docs: B-1 — Redis moves the session and leaves the tokens behind

Adding Spring Session Redis grows the context by 81 beans and swaps sessionRepository for RedisSessionRepository, while authorizedClientService stays InMemoryOAuth2AuthorizedClientService. The user then reads as logged in with principal labuser while accessTokenStoredOnServer is false, which is worse than being logged out. Redis holds only the security context, serialized with Java native serialization, and the refresh token is not there to encrypt in the first place. Three problems on the way: Kubernetes service links overwrote REDIS_PORT with a tcp:// URL, the tests tried to reach Redis, and the resource server was never deployed so a DNS failure looked like a token failure. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
docs: B-0 — deploy the BFF and read what autoconfiguration actually chose
2026-09-04 14:05:02 +09:00 · 2026-09-04 13:48:33 +09:00
49 changed files with 1760 additions and 0 deletions
@@ -82,3 +82,62 @@
 [  776007ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  792298ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  803509ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  822917ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  827374ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  847278ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  867460ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  875338ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  886296ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  900938ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  912511ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  917067ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  924405ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  930435ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  942211ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  953146ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  957153ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  969140ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [  984088ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1003544ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1014908ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1020851ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1034668ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1040406ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1056887ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1062828ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1073375ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1085052ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1102031ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1110039ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1129341ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1132300ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1133670ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1142705ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1160906ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1172400ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1190482ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1196673ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1213666ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1225136ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1228310ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1242751ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1243874ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1256126ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1274444ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1288526ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1307058ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1320986ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1325134ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1335974ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1344832ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1354780ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1364165ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1383346ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1399019ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1400207ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1413875ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1423809ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1427502ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1430773ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1436408ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
 [ 1447464ms] [ERROR] WebSocket connection to 'wss://app2.hyeonworks.com/api/live/ws' failed: Error during WebSocket handshake: Unexpected response code: 400 @ https://app2.hyeonworks.com/public/build/1518.a3f1f690c084a37f01c7.js:362
@@ -0,0 +1 @@
 [     207ms] [ERROR] Failed to load resource: the server responded with a status of 404 () @ https://app1.hyeonworks.com/favicon.ico:0
@@ -0,0 +1 @@
 [     236ms] [ERROR] Failed to load resource: the server responded with a status of 500 () @ https://app1.hyeonworks.com/bff/api/me:0
@@ -0,0 +1,2 @@
 [    7292ms] [ERROR] Access to fetch at 'https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=WWc76H7TY73Fbsdc41B2nRD5exkXqHcohLh4WdJB4AA%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=A4TXweuKS4Y5HdZ63rLJUez1ZOyI2em6zs3OIfTXLFo&code_challenge=wPr8PXG0lcUvie7Wo91YrVMhOUYq0KtEU4PxVJ0_CWA&code_challenge_method=S256' (redirected from 'https://app1.hyeonworks.com/bff/api/me') from origin 'https://app1.hyeonworks.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. @ https://app1.hyeonworks.com/bff/token-boundary:0
 [    7293ms] [ERROR] Failed to load resource: net::ERR_FAILED @ https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=WWc76H7TY73Fbsdc41B2nRD5exkXqHcohLh4WdJB4AA%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=A4TXweuKS4Y5HdZ63rLJUez1ZOyI2em6zs3OIfTXLFo&code_challenge=wPr8PXG0lcUvie7Wo91YrVMhOUYq0KtEU4PxVJ0_CWA&code_challenge_method=S256:0
@@ -0,0 +1,2 @@
 [    6726ms] [ERROR] Access to fetch at 'https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=GGupuPr3ZklKp8ah99r7h7mNHEq9yTsEWZr85WyXevE%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=rPVvEOvG7rzssAjR7pP67qNvoY2W6ZVpIpKYz1LGoU8&code_challenge=qoKRLRrzB7z9CU_rlaAxJ7UYcRZswyqmDi8PgxmaWM0&code_challenge_method=S256' (redirected from 'https://app1.hyeonworks.com/bff/api/me') from origin 'https://app1.hyeonworks.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. @ https://app1.hyeonworks.com/:0
 [    6726ms] [ERROR] Failed to load resource: net::ERR_FAILED @ https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=GGupuPr3ZklKp8ah99r7h7mNHEq9yTsEWZr85WyXevE%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=rPVvEOvG7rzssAjR7pP67qNvoY2W6ZVpIpKYz1LGoU8&code_challenge=qoKRLRrzB7z9CU_rlaAxJ7UYcRZswyqmDi8PgxmaWM0&code_challenge_method=S256:0
@@ -0,0 +1,7 @@
 - main [ref=f21e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f21e3]
  - paragraph [ref=f21e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f21e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f21e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f21e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f21e8] [cursor=pointer]
@@ -0,0 +1,16 @@
 - generic [ref=f22e3]:
  - banner [ref=f22e4]:
    - generic [ref=f22e5]: keycloak-patterns
  - main [ref=f22e6]:
    - heading "Sign in to your account" [level=1] [ref=f22e8]
    - generic [ref=f22e12]:
      - generic [ref=f22e13]:
        - generic [ref=f22e14]: Username or email
        - textbox "Username or email" [active] [ref=f22e17]
      - generic [ref=f22e18]:
        - generic [ref=f22e19]: Password
        - generic [ref=f22e21]:
          - textbox "Password" [ref=f22e24]
          - button "Show password" [ref=f22e26] [cursor=pointer]:
            - generic [aria-hidden] [ref=f22e27]: 
      - button "Sign In" [ref=f22e30] [cursor=pointer]
@@ -0,0 +1,20 @@
 - generic [ref=f23e3]:
  - banner [ref=f23e4]:
    - generic [ref=f23e5]: keycloak-patterns
  - main [ref=f23e6]:
    - heading "Update Account Information" [level=1] [ref=f23e8]
    - generic [ref=f23e9]:
      - generic [ref=f23e10]: "* Required fields"
      - generic [ref=f23e13]:
        - generic [ref=f23e14]:
          - generic [ref=f23e15]: Email *
          - textbox "Email" [ref=f23e19]: labuser@example.com
        - generic [ref=f23e20]:
          - generic [ref=f23e21]: First name *
          - textbox "First name" [invalid] [ref=f23e25]
          - generic [ref=f23e26]: Please specify this field.
        - generic [ref=f23e31]:
          - generic [ref=f23e32]: Last name *
          - textbox "Last name" [invalid] [ref=f23e36]
          - generic [ref=f23e37]: Please specify this field.
        - button "Submit" [ref=f23e44]
@@ -0,0 +1,20 @@
 - generic [ref=f23e3]:
  - banner [ref=f23e4]:
    - generic [ref=f23e5]: keycloak-patterns
  - main [ref=f23e6]:
    - heading "Update Account Information" [level=1] [ref=f23e8]
    - generic [ref=f23e9]:
      - generic [ref=f23e10]: "* Required fields"
      - generic [ref=f23e13]:
        - generic [ref=f23e14]:
          - generic [ref=f23e15]: Email *
          - textbox "Email" [ref=f23e19]: labuser@example.com
        - generic [ref=f23e20]:
          - generic [ref=f23e21]: First name *
          - textbox "First name" [invalid] [ref=f23e25]: Lab
          - generic [ref=f23e26]: Please specify this field.
        - generic [ref=f23e31]:
          - generic [ref=f23e32]: Last name *
          - textbox "Last name" [active] [invalid] [ref=f23e36]: User
          - generic [ref=f23e37]: Please specify this field.
        - button "Submit" [ref=f23e44]
@@ -0,0 +1,7 @@
 - main [ref=f24e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f24e3]
  - paragraph [ref=f24e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f24e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f24e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f24e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f24e8] [cursor=pointer]
@@ -0,0 +1,16 @@
 - generic [ref=f25e3]:
  - banner [ref=f25e4]:
    - generic [ref=f25e5]: keycloak-patterns
  - main [ref=f25e6]:
    - heading "Sign in to your account" [level=1] [ref=f25e8]
    - generic [ref=f25e12]:
      - generic [ref=f25e13]:
        - generic [ref=f25e14]: Username or email
        - textbox "Username or email" [active] [ref=f25e17]
      - generic [ref=f25e18]:
        - generic [ref=f25e19]: Password
        - generic [ref=f25e21]:
          - textbox "Password" [ref=f25e24]
          - button "Show password" [ref=f25e26] [cursor=pointer]:
            - generic [aria-hidden] [ref=f25e27]: 
      - button "Sign In" [ref=f25e30] [cursor=pointer]
@@ -0,0 +1,9 @@
 - generic [ref=f26e2]:
  - heading "Login with OAuth 2.0" [level=2] [ref=f26e3]
  - alert [ref=f26e4]: Invalid credentials
  - table [ref=f26e5]:
    - rowgroup [ref=f26e6]:
      - row [ref=f26e7]:
        - cell [ref=f26e8]:
          - link "keycloak" [ref=f26e9] [cursor=pointer]:
            - /url: /oauth2/authorization/keycloak
@@ -0,0 +1,7 @@
 - main [ref=f27e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f27e3]
  - paragraph [ref=f27e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f27e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f27e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f27e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f27e8] [cursor=pointer]
@@ -0,0 +1,7 @@
 - main [ref=f27e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f27e3]
  - paragraph [ref=f27e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f27e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f27e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f27e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f27e8] [cursor=pointer]
@@ -0,0 +1,7 @@
 - main [ref=f27e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f27e3]
  - paragraph [ref=f27e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f27e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f27e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f27e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f27e8] [cursor=pointer]
@@ -0,0 +1 @@
 - generic [active] [ref=f28e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":true,\"refreshTokenStoredOnServer\":true,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"
@@ -0,0 +1,7 @@
 - main [ref=f29e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f29e3]
  - paragraph [ref=f29e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f29e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f29e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f29e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f29e8] [cursor=pointer]
@@ -0,0 +1 @@
 - generic [active] [ref=f30e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"
@@ -0,0 +1,5 @@
 - generic [active] [ref=f31e1]:
  - heading "Whitelabel Error Page" [level=1] [ref=f31e2]
  - paragraph [ref=f31e3]: This application has no explicit mapping for /error, so you are seeing this as a fallback.
  - generic [ref=f31e4]: Fri Sep 04 05:00:51 GMT 2026
  - generic [ref=f31e5]: There was an unexpected error (type=Internal Server Error, status=500).
@@ -0,0 +1 @@
 - generic [active] [ref=f32e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"
@@ -0,0 +1,7 @@
 - main [ref=f33e2]:
  - heading "AP3 · Backend-for-Frontend" [level=1] [ref=f33e3]
  - paragraph [ref=f33e4]: 브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource Server 요청에 붙입니다.
  - button "Keycloak 로그인" [ref=f33e5] [cursor=pointer]
  - button "token 경계 확인" [ref=f33e6] [cursor=pointer]
  - button "BFF 경유 API 호출" [ref=f33e7] [cursor=pointer]
  - button "CSRF token으로 상태 변경" [ref=f33e8] [cursor=pointer]
@@ -0,0 +1 @@
 - generic [active] [ref=f34e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"
@@ -0,0 +1 @@
 target/
@@ -0,0 +1,14 @@
 FROM maven:3.9.11-eclipse-temurin-21-alpine AS build
 WORKDIR /workspace
 COPY pom.xml .
 RUN mvn --batch-mode dependency:go-offline
 COPY src src
 RUN mvn --batch-mode verify
 FROM eclipse-temurin:21-jre-alpine
 RUN addgroup -S spring && adduser -S spring -G spring
 WORKDIR /app
 COPY --from=build /workspace/target/keycloak-bff.jar app.jar
 USER spring:spring
 EXPOSE 8083
 ENTRYPOINT ["java", "-jar", "/app/app.jar"]
@@ -0,0 +1,71 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <project xmlns="http://maven.apache.org/POM/4.0.0"
         xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
         xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 https://maven.apache.org/xsd/maven-4.0.0.xsd">
    <modelVersion>4.0.0</modelVersion>
    <parent>
        <groupId>org.springframework.boot</groupId>
        <artifactId>spring-boot-starter-parent</artifactId>
        <version>3.5.16</version>
        <relativePath/>
    </parent>
    <groupId>com.example</groupId>
    <artifactId>keycloak-bff</artifactId>
    <version>0.0.1-SNAPSHOT</version>
    <name>keycloak-bff</name>
    <properties>
        <java.version>21</java.version>
    </properties>
    <dependencies>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-actuator</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-oauth2-client</artifactId>
        </dependency>
        <!-- B-1: Application Session 을 Redis 로 옮긴다.
             spring-session-data-redis 가 SessionRepository 를 갈아끼우고,
             spring-boot-starter-data-redis 가 연결(Lettuce)을 제공한다.
             둘 다 있어야 자동구성이 걸린다 — 하나만 넣으면 조용히 in-memory 로 남는다. -->
        <dependency>
            <groupId>org.springframework.session</groupId>
            <artifactId>spring-session-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-data-redis</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-web</artifactId>
        </dependency>
        <dependency>
            <groupId>org.springframework.boot</groupId>
            <artifactId>spring-boot-starter-test</artifactId>
            <scope>test</scope>
        </dependency>
        <dependency>
            <groupId>org.springframework.security</groupId>
            <artifactId>spring-security-test</artifactId>
            <scope>test</scope>
        </dependency>
    </dependencies>
    <build>
        <finalName>keycloak-bff</finalName>
        <plugins>
            <plugin>
                <groupId>org.springframework.boot</groupId>
                <artifactId>spring-boot-maven-plugin</artifactId>
            </plugin>
        </plugins>
    </build>
 </project>
@@ -0,0 +1,12 @@
 package com.example.keycloakpattern.bff;
 import org.springframework.boot.SpringApplication;
 import org.springframework.boot.autoconfigure.SpringBootApplication;
@SpringBootApplication
 public class BffApplication {
    public static void main(String[] args) {
        SpringApplication.run(BffApplication.class, args);
    }
 }
@@ -0,0 +1,112 @@
 package com.example.keycloakpattern.bff;
 import java.util.LinkedHashMap;
 import java.util.Map;
 import java.util.concurrent.atomic.AtomicReference;
 import org.springframework.beans.factory.annotation.Value;
 import org.springframework.http.CacheControl;
 import org.springframework.http.HttpHeaders;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.core.Authentication;
 import org.springframework.security.oauth2.client.OAuth2AuthorizeRequest;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.PostMapping;
 import org.springframework.web.bind.annotation.RequestParam;
 import org.springframework.web.bind.annotation.RestController;
 import org.springframework.web.client.RestClient;
 import org.springframework.web.server.ResponseStatusException;
 import static org.springframework.http.HttpStatus.UNAUTHORIZED;
@RestController
 public class BffController {
    private final OAuth2AuthorizedClientService authorizedClientService;
    private final OAuth2AuthorizedClientManager authorizedClientManager;
    private final RestClient resourceApi;
    private final AtomicReference<String> theme = new AtomicReference<>("system");
    public BffController(
        OAuth2AuthorizedClientService authorizedClientService,
        OAuth2AuthorizedClientManager authorizedClientManager,
        RestClient.Builder restClientBuilder,
        @Value("${resource-api.base-url}") String resourceApiBaseUrl
    ) {
        this.authorizedClientService = authorizedClientService;
        this.authorizedClientManager = authorizedClientManager;
        this.resourceApi = restClientBuilder.baseUrl(resourceApiBaseUrl).build();
    }
    @GetMapping("/bff/token-boundary")
    ResponseEntity<Map<String, Object>> tokenBoundary(Authentication authentication) {
        OAuth2AuthorizedClient client = authorizedClientService.loadAuthorizedClient(
            "keycloak",
            authentication.getName()
        );
        Map<String, Object> response = new LinkedHashMap<>();
        response.put("pattern", "AP3-backend-for-frontend");
        response.put("principal", authentication.getName());
        response.put("accessTokenStoredOnServer", client != null
            && client.getAccessToken() != null);
        response.put("refreshTokenStoredOnServer", client != null
            && client.getRefreshToken() != null);
        response.put("browserTokenCount", 0);
        response.put("csrfProtectionEnabled", true);
        return ResponseEntity.ok()
            .cacheControl(CacheControl.noStore())
            .header("Pragma", "no-cache")
            .body(response);
    }
    @GetMapping("/bff/api/me")
    ResponseEntity<?> currentUser(Authentication authentication) {
        OAuth2AuthorizedClient client = authorizedClient(authentication);
        return resourceApi.get()
            .uri("/api/me")
            .header(
                HttpHeaders.AUTHORIZATION,
                "Bearer " + client.getAccessToken().getTokenValue()
            )
            .retrieve()
            .toEntity(Map.class);
    }
    @PostMapping("/bff/api/preferences")
    Map<String, Object> updatePreference(
        Authentication authentication,
        @RequestParam(defaultValue = "system") String theme
    ) {
        this.theme.set(theme);
        return Map.of(
            "updated", true,
            "theme", this.theme.get(),
            "principal", authentication.getName()
        );
    }
    @GetMapping("/bff/api/preferences")
    Map<String, String> preference() {
        return Map.of("theme", theme.get());
    }
    private OAuth2AuthorizedClient authorizedClient(Authentication authentication) {
        OAuth2AuthorizeRequest request = OAuth2AuthorizeRequest
            .withClientRegistrationId("keycloak")
            .principal(authentication)
            .build();
        OAuth2AuthorizedClient client = authorizedClientManager.authorize(request);
        if (client == null || client.getAccessToken() == null) {
            throw new ResponseStatusException(
                UNAUTHORIZED,
                "No authorized Keycloak client is available"
            );
        }
        return client;
    }
 }
@@ -0,0 +1,25 @@
 package com.example.keycloakpattern.bff;
 import java.util.Map;
 import org.springframework.http.CacheControl;
 import org.springframework.http.ResponseEntity;
 import org.springframework.security.web.csrf.CsrfToken;
 import org.springframework.web.bind.annotation.GetMapping;
 import org.springframework.web.bind.annotation.RestController;
@RestController
 public class CsrfController {
    @GetMapping("/bff/csrf")
    ResponseEntity<Map<String, String>> csrf(CsrfToken csrfToken) {
        return ResponseEntity.ok()
            .cacheControl(CacheControl.noStore())
            .header("Pragma", "no-cache")
            .body(Map.of(
                "headerName", csrfToken.getHeaderName(),
                "parameterName", csrfToken.getParameterName(),
                "token", csrfToken.getToken()
            ));
    }
 }
@@ -0,0 +1,85 @@
 package com.example.keycloakpattern.bff;
 import org.springframework.context.annotation.Bean;
 import org.springframework.context.annotation.Configuration;
 import org.springframework.security.config.annotation.web.builders.HttpSecurity;
 import org.springframework.security.oauth2.client.AuthorizedClientServiceOAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProvider;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientProviderBuilder;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.client.registration.ClientRegistrationRepository;
 import org.springframework.security.oauth2.client.web.DefaultOAuth2AuthorizationRequestResolver;
 import org.springframework.security.oauth2.client.web.OAuth2AuthorizationRequestCustomizers;
 import org.springframework.security.web.SecurityFilterChain;
 import org.springframework.security.web.csrf.CookieCsrfTokenRepository;
@Configuration
 public class SecurityConfig {
    @Bean
    SecurityFilterChain bffSecurity(
        HttpSecurity http,
        ClientRegistrationRepository clientRegistrationRepository
    ) throws Exception {
        DefaultOAuth2AuthorizationRequestResolver authorizationRequestResolver =
            new DefaultOAuth2AuthorizationRequestResolver(
                clientRegistrationRepository,
                "/oauth2/authorization"
            );
        authorizationRequestResolver.setAuthorizationRequestCustomizer(
            OAuth2AuthorizationRequestCustomizers.withPkce()
        );
        CookieCsrfTokenRepository csrfTokenRepository =
            CookieCsrfTokenRepository.withHttpOnlyFalse();
        csrfTokenRepository.setCookiePath("/");
        return http
            .csrf(csrf -> csrf
                .csrfTokenRepository(csrfTokenRepository)
                .csrfTokenRequestHandler(new SpaCsrfTokenRequestHandler()))
            .authorizeHttpRequests(authorize -> authorize
                .requestMatchers(
                    "/",
                    "/index.html",
                    "/app.js",
                    "/favicon.ico",
                    "/actuator/health",
                    "/actuator/health/**",
                    // 실험대 전용 — B-0 은 "자동구성이 실제로 무엇을 골랐는가"를
                    // 밖에서 읽어야 답할 수 있다. 운영에서는 절대 열지 않는다:
                    // /actuator/beans 와 /actuator/env 는 내부 구조와 설정값을
                    // 그대로 드러낸다.
                    "/actuator/**"
                )
                .permitAll()
                .anyRequest()
                .authenticated())
            .oauth2Login(oauth2 -> oauth2
                .authorizationEndpoint(endpoint -> endpoint
                    .authorizationRequestResolver(authorizationRequestResolver))
                .defaultSuccessUrl("/", true))
            .build();
    }
    @Bean
    OAuth2AuthorizedClientManager authorizedClientManager(
        ClientRegistrationRepository clientRegistrationRepository,
        OAuth2AuthorizedClientService authorizedClientService
    ) {
        OAuth2AuthorizedClientProvider authorizedClientProvider =
            OAuth2AuthorizedClientProviderBuilder.builder()
                .authorizationCode()
                .refreshToken()
                .build();
        AuthorizedClientServiceOAuth2AuthorizedClientManager manager =
            new AuthorizedClientServiceOAuth2AuthorizedClientManager(
                clientRegistrationRepository,
                authorizedClientService
            );
        manager.setAuthorizedClientProvider(authorizedClientProvider);
        return manager;
    }
 }
@@ -0,0 +1,40 @@
 package com.example.keycloakpattern.bff;
 import java.util.function.Supplier;
 import jakarta.servlet.http.HttpServletRequest;
 import jakarta.servlet.http.HttpServletResponse;
 import org.springframework.security.web.csrf.CsrfToken;
 import org.springframework.security.web.csrf.CsrfTokenRequestAttributeHandler;
 import org.springframework.security.web.csrf.CsrfTokenRequestHandler;
 import org.springframework.security.web.csrf.XorCsrfTokenRequestAttributeHandler;
 import org.springframework.util.StringUtils;
 final class SpaCsrfTokenRequestHandler implements CsrfTokenRequestHandler {
    private final CsrfTokenRequestHandler plain =
        new CsrfTokenRequestAttributeHandler();
    private final CsrfTokenRequestHandler xor =
        new XorCsrfTokenRequestAttributeHandler();
    @Override
    public void handle(
        HttpServletRequest request,
        HttpServletResponse response,
        Supplier<CsrfToken> deferredCsrfToken
    ) {
        xor.handle(request, response, deferredCsrfToken);
    }
    @Override
    public String resolveCsrfTokenValue(
        HttpServletRequest request,
        CsrfToken csrfToken
    ) {
        if (StringUtils.hasText(request.getHeader(csrfToken.getHeaderName()))) {
            return plain.resolveCsrfTokenValue(request, csrfToken);
        }
        return xor.resolveCsrfTokenValue(request, csrfToken);
    }
 }
@@ -0,0 +1,63 @@
 server:
  port: ${SERVER_PORT:8083}
  servlet:
    session:
      cookie:
        name: AP3_SESSION
        http-only: true
        same-site: lax
 spring:
  application:
    name: keycloak-bff
  data:
    redis:
      host: ${REDIS_HOST:localhost}
      port: ${REDIS_PORT:6379}
  session:
    # Application Session 만 Redis 로 간다. OAuth2AuthorizedClient 는
    # 이 설정과 무관하며 여전히 InMemory 다 — 조회 키가 다르기 때문이다(B-0).
    store-type: ${SPRING_SESSION_STORE_TYPE:redis}
    timeout: ${SPRING_SESSION_TIMEOUT:30m}
    redis:
      namespace: bff:session
  security:
    oauth2:
      client:
        registration:
          keycloak:
            provider: keycloak
            client-id: bff-confidential
            client-secret: ${KEYCLOAK_CLIENT_SECRET}
            client-authentication-method: client_secret_basic
            authorization-grant-type: authorization_code
            redirect-uri: "{baseUrl}/login/oauth2/code/{registrationId}"
            scope:
              - openid
              - profile
              - email
        provider:
          keycloak:
            # 브라우저가 리다이렉트되는 주소와 BFF 가 서버끼리 부르는 주소는 다르다.
            # 앞의 것은 외부에서 닿는 이름이어야 하고, 뒤의 것은 클러스터 안 주소여도 된다.
            authorization-uri: ${KC_ISSUER_EXTERNAL:http://localhost:8080/realms/keycloak-patterns}/protocol/openid-connect/auth
            token-uri:         ${KC_ISSUER_INTERNAL:http://keycloak:8080/realms/keycloak-patterns}/protocol/openid-connect/token
            jwk-set-uri:       ${KC_ISSUER_INTERNAL:http://keycloak:8080/realms/keycloak-patterns}/protocol/openid-connect/certs
            user-info-uri:     ${KC_ISSUER_INTERNAL:http://keycloak:8080/realms/keycloak-patterns}/protocol/openid-connect/userinfo
            user-name-attribute: preferred_username
 resource-api:
  base-url: ${RESOURCE_API_BASE_URL:http://localhost:8081}
 management:
  endpoint:
    health:
      probes:
        enabled: true
      show-details: always
  endpoints:
    web:
      exposure:
        # beans / conditions 는 B-0 에서 "자동구성이 실제로 무엇을 골랐는가"를
        # 보기 위해 연다. 운영에 그대로 두면 내부 구조가 노출된다.
        include: health,info,beans,conditions,env
@@ -0,0 +1,59 @@
 const result = document.querySelector("#result");
 function render(value) {
  result.textContent = JSON.stringify(value, null, 2);
 }
 function readCookie(name) {
  const prefix = `${encodeURIComponent(name)}=`;
  const value = document.cookie
    .split("; ")
    .find((cookie) => cookie.startsWith(prefix));
  return value ? decodeURIComponent(value.slice(prefix.length)) : null;
 }
 async function request(path, options = {}) {
  const response = await fetch(path, {
    ...options,
    headers: { Accept: "application/json", ...options.headers },
  });
  if (response.redirected || response.status === 401) {
    window.location.assign("/oauth2/authorization/keycloak");
    return null;
  }
  const body = await response.json();
  render({ status: response.status, ...body });
  return { response, body };
 }
 document.querySelector("#login").addEventListener("click", () => {
  window.location.assign("/oauth2/authorization/keycloak");
 });
 document.querySelector("#inspect").addEventListener("click", () => {
  void request("/bff/token-boundary");
 });
 document.querySelector("#call-bff").addEventListener("click", () => {
  void request("/bff/api/me");
 });
 document.querySelector("#change-with-csrf").addEventListener("click", async () => {
  const csrfResponse = await fetch("/bff/csrf", {
    headers: { Accept: "application/json" },
  });
  const csrf = await csrfResponse.json();
  const csrfToken = readCookie("XSRF-TOKEN");
  if (!csrfToken) {
    render({ status: 500, error: "XSRF-TOKEN cookie was not created" });
    return;
  }
  await request("/bff/api/preferences", {
    method: "POST",
    body: new URLSearchParams({ theme: "dark" }),
    headers: {
      "Content-Type": "application/x-www-form-urlencoded",
      [csrf.headerName]: csrfToken,
    },
  });
 });
@@ -0,0 +1,31 @@
 <!doctype html>
 <html lang="ko">
 <head>
  <meta charset="utf-8">
  <meta name="viewport" content="width=device-width, initial-scale=1">
  <title>AP3 · Backend-for-Frontend</title>
  <style>
    :root { color-scheme: light dark; font-family: system-ui, sans-serif; }
    body { max-width: 58rem; margin: 6vh auto; padding: 0 1.5rem; line-height: 1.6; }
    button { margin: 0 0.5rem 0.5rem 0; padding: 0.6rem 0.9rem; cursor: pointer; }
    pre { min-height: 9rem; padding: 1rem; border-radius: 0.4rem;
      background: color-mix(in srgb, CanvasText 9%, Canvas); white-space: pre-wrap; }
  </style>
 </head>
 <body>
  <main>
    <h1>AP3 · Backend-for-Frontend</h1>
    <p>
      브라우저에는 OAuth token이 전혀 전달되지 않습니다. HttpOnly session
      cookie로 BFF만 호출하고, BFF가 서버 보관 access token을 Resource
      Server 요청에 붙입니다.
    </p>
    <button id="login" type="button">Keycloak 로그인</button>
    <button id="inspect" type="button">token 경계 확인</button>
    <button id="call-bff" type="button">BFF 경유 API 호출</button>
    <button id="change-with-csrf" type="button">CSRF token으로 상태 변경</button>
    <pre id="result" aria-live="polite"></pre>
  </main>
  <script type="module" src="/app.js"></script>
 </body>
 </html>
@@ -0,0 +1,93 @@
 package com.example.keycloakpattern.bff;
 import static org.mockito.Mockito.mock;
 import static org.mockito.Mockito.when;
 import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.oidcLogin;
 import static org.springframework.security.test.web.servlet.request.SecurityMockMvcRequestPostProcessors.csrf;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.get;
 import static org.springframework.test.web.servlet.request.MockMvcRequestBuilders.post;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.header;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.jsonPath;
 import static org.springframework.test.web.servlet.result.MockMvcResultMatchers.status;
 import org.junit.jupiter.api.Test;
 import org.springframework.beans.factory.annotation.Autowired;
 import org.springframework.boot.test.autoconfigure.web.servlet.AutoConfigureMockMvc;
 import org.springframework.boot.test.context.SpringBootTest;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClient;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientManager;
 import org.springframework.security.oauth2.client.OAuth2AuthorizedClientService;
 import org.springframework.security.oauth2.core.OAuth2AccessToken;
 import org.springframework.security.oauth2.core.OAuth2RefreshToken;
 import org.springframework.test.context.bean.override.mockito.MockitoBean;
 import org.springframework.test.web.servlet.MockMvc;
@SpringBootTest(properties = {
    "KEYCLOAK_CLIENT_SECRET=test-only-secret",
    // 테스트는 Redis 를 띄우지 않는다. store-type=none 이면 자동구성이
    // 서블릿 컨테이너 기본 세션으로 되돌아가 컨텍스트가 뜬다.
    "spring.session.store-type=none",
    "resource-api.base-url=http://127.0.0.1:9"
 })
@AutoConfigureMockMvc
 class BffControllerTest {
    @Autowired
    private MockMvc mockMvc;
    @MockitoBean
    private OAuth2AuthorizedClientService authorizedClientService;
    @MockitoBean
    private OAuth2AuthorizedClientManager authorizedClientManager;
    @Test
    void reportsServerTokenCustodyWithoutReturningTokens() throws Exception {
        OAuth2AuthorizedClient client = mock(OAuth2AuthorizedClient.class);
        when(client.getAccessToken()).thenReturn(mock(OAuth2AccessToken.class));
        when(client.getRefreshToken()).thenReturn(mock(OAuth2RefreshToken.class));
        when(authorizedClientService.loadAuthorizedClient("keycloak", "test-subject"))
            .thenReturn(client);
        mockMvc.perform(get("/bff/token-boundary").with(oidcLogin()
                .idToken(token -> token.subject("test-subject"))))
            .andExpect(status().isOk())
            .andExpect(header().string("Cache-Control", "no-store"))
            .andExpect(jsonPath("$.accessTokenStoredOnServer").value(true))
            .andExpect(jsonPath("$.refreshTokenStoredOnServer").value(true))
            .andExpect(jsonPath("$.browserTokenCount").value(0))
            .andExpect(jsonPath("$.csrfProtectionEnabled").value(true))
            .andExpect(jsonPath("$.access_token").doesNotExist())
            .andExpect(jsonPath("$.refresh_token").doesNotExist());
    }
    @Test
    void rejectsStateChangeWithoutCsrfToken() throws Exception {
        mockMvc.perform(post("/bff/api/preferences")
                .param("theme", "attacker")
                .with(oidcLogin().idToken(token -> token.subject("test-subject"))))
            .andExpect(status().isForbidden());
    }
    @Test
    void acceptsStateChangeWithCsrfToken() throws Exception {
        mockMvc.perform(post("/bff/api/preferences")
                .param("theme", "dark")
                .with(oidcLogin().idToken(token -> token.subject("test-subject")))
                .with(csrf()))
            .andExpect(status().isOk())
            .andExpect(jsonPath("$.updated").value(true))
            .andExpect(jsonPath("$.theme").value("dark"));
    }
    @Test
    void exposesSpaCsrfTokenWithoutCaching() throws Exception {
        mockMvc.perform(get("/bff/csrf").with(oidcLogin()
                .idToken(token -> token.subject("test-subject"))))
            .andExpect(status().isOk())
            .andExpect(header().string("Cache-Control", "no-store"))
            .andExpect(header().exists("Set-Cookie"))
            .andExpect(jsonPath("$.headerName").value("X-XSRF-TOKEN"))
            .andExpect(jsonPath("$.token").isNotEmpty());
    }
 }
@@ -0,0 +1,181 @@
 # BFF (2 replicas) + Redis, for the B-layer experiments.
 #
 # The BFF is deployed FIRST WITHOUT any session store wiring. That is deliberate:
 # B-0 asks what Spring Boot's autoconfiguration actually picks when nothing is
 # configured, and the only honest way to answer is to look at a running instance
 # that has been given nothing. Redis is deployed alongside but left unused until
 # B-1 turns it on.
 #
 #   kubectl apply -f deploy/lab/k8s/bff-redis.yaml
 #
 # Image comes from the workstation, not a registry:
 #   docker build -t keycloak-pattern-bff:lab bff/
 #   docker save keycloak-pattern-bff:lab | ssh test-server "ssh kc-lab-1 'sudo k3s ctr images import -'"
 #   (repeat for kc-lab-2)
 # so imagePullPolicy must stay Never on both replicas.
 apiVersion: v1
 kind: Secret
 metadata:
  name: bff-secrets
  namespace: keycloak-lab
 type: Opaque
 stringData:
  # Matches the client created with kcadm in the keycloak-patterns realm.
  # Base64 in etcd is not encryption — see D-3.
  KEYCLOAK_CLIENT_SECRET: bff-lab-secret
 ---
 # Redis. No persistence yet: `--save ""` and no appendonly, so a restart loses
 # everything. B-5 and B-6 compare that against RDB and AOF, which is easier to
 # reason about when the starting point is "nothing survives".
 apiVersion: apps/v1
 kind: Deployment
 metadata:
  name: redis
  namespace: keycloak-lab
 spec:
  replicas: 1
  selector:
    matchLabels: { app: redis }
  template:
    metadata:
      labels: { app: redis }
    spec:
      # Same node as postgres so a node-loss experiment takes both stores at
      # once, matching how A-4 was set up.
      nodeSelector:
        kubernetes.io/hostname: kc-lab-2
      containers:
        - name: redis
          image: redis:7.4-alpine
          args: ["redis-server", "--save", "", "--appendonly", "no"]
          ports:
            - containerPort: 6379
              name: redis
          readinessProbe:
            exec: { command: ["redis-cli", "ping"] }
            initialDelaySeconds: 3
          resources:
            requests: { memory: 32Mi, cpu: 20m }
            limits:   { memory: 128Mi }
 ---
 apiVersion: v1
 kind: Service
 metadata:
  name: redis
  namespace: keycloak-lab
 spec:
  selector: { app: redis }
  ports:
    - port: 6379
      targetPort: redis
 ---
 apiVersion: apps/v1
 kind: Deployment
 metadata:
  name: bff
  namespace: keycloak-lab
 spec:
  # Two replicas is the whole point: Q1 and Q2 only exist because a request can
  # land on an instance that did not handle the login.
  replicas: 2
  selector:
    matchLabels: { app: bff }
  template:
    metadata:
      labels: { app: bff }
    spec:
      # Spread across both nodes so "the other instance" is genuinely another
      # machine, not another process on the same kernel.
      topologySpreadConstraints:
        - maxSkew: 1
          topologyKey: kubernetes.io/hostname
          whenUnsatisfiable: ScheduleAnyway
          labelSelector:
            matchLabels: { app: bff }
      # 쿠버네티스는 같은 네임스페이스의 Service 마다 Docker link 시절의
      # 환경변수를 자동 주입한다: REDIS_PORT=tcp://10.43.57.116:6379.
      # 그것이 application.yml 의 ${REDIS_PORT:6379} 를 덮어써서 기동이 실패했다.
      #   Failed to bind properties under 'spring.data.redis.port' to int:
      #     Value: "tcp://10.43.57.116:6379"
      # 이 주입 자체를 끄는 것이 근본 처방이다. 이름을 바꿔 피하면 다음 사람이
      # 같은 함정에 다시 빠진다.
      enableServiceLinks: false
      containers:
        - name: bff
          image: keycloak-pattern-bff:lab
          imagePullPolicy: Never
          ports:
            - containerPort: 8083
              name: http
          env:
            # The browser is redirected to the public name; the BFF calls the
            # token endpoint over the cluster network. Getting these two the same
            # way round is what the 2-hop header experiment was about.
            - name: KC_ISSUER_EXTERNAL
              value: https://auth.hyeonworks.com/realms/keycloak-patterns
            - name: KC_ISSUER_INTERNAL
              value: http://keycloak.keycloak-lab.svc:8080/realms/keycloak-patterns
            # echo 는 header-lab 네임스페이스의 8081 이다. 다른 네임스페이스의
            # 서비스는 <svc>.<ns>.svc 로 부른다. 이름을 틀리면 500 이 나는데
            # 원인은 UnresolvedAddressException 이지 토큰 문제가 아니다.
            - name: RESOURCE_API_BASE_URL
              value: http://echo.header-lab.svc:8081
            - name: KEYCLOAK_CLIENT_SECRET
              valueFrom:
                secretKeyRef: { name: bff-secrets, key: KEYCLOAK_CLIENT_SECRET }
            # Spring needs to know it is behind TLS termination, for the same
            # reason Keycloak needs KC_PROXY_HEADERS. Without it the redirect_uri
            # it builds comes back as http:// and Keycloak rejects it.
            - name: SERVER_FORWARD_HEADERS_STRATEGY
              value: native
            # B-1: Application Session 을 Redis 로 옮긴다.
            # OAuth2AuthorizedClient 는 이것으로 옮겨지지 않는다 — 조회 키가
            # 다르기 때문이며, B-0 에서 확인한 사실이다.
            - name: SPRING_SESSION_STORE_TYPE
              value: redis
            - name: REDIS_HOST
              value: redis.keycloak-lab.svc
            - name: REDIS_PORT
              value: "6379"
            - name: JAVA_TOOL_OPTIONS
              value: "-Xms128m -Xmx320m"
          readinessProbe:
            httpGet: { path: /actuator/health/readiness, port: http }
            initialDelaySeconds: 20
            failureThreshold: 30
          livenessProbe:
            httpGet: { path: /actuator/health/liveness, port: http }
            initialDelaySeconds: 60
          resources:
            requests: { memory: 320Mi, cpu: 100m }
            limits:   { memory: 512Mi }
 ---
 apiVersion: v1
 kind: Service
 metadata:
  name: bff
  namespace: keycloak-lab
 spec:
  selector: { app: bff }
  ports:
    - port: 8083
      targetPort: http
 ---
 apiVersion: networking.k8s.io/v1
 kind: Ingress
 metadata:
  name: bff
  namespace: keycloak-lab
 spec:
  ingressClassName: traefik
  rules:
    - host: app1.hyeonworks.com
      http:
        paths:
          - path: /
            pathType: Prefix
            backend:
              service:
                name: bff
                port:
                  number: 8083
@@ -0,0 +1,21 @@
 === 배포 전 자원 ===
 Mem:           11648        7329         280           4        4377        4319
 NAME       CPU(cores)   CPU(%)   MEMORY(bytes)   MEMORY(%)   
 kc-lab-1   115m         5%       2192Mi          44%         
 kc-lab-2   121m         6%       1324Mi          33%         
 === 배포 ===
 secret/bff-secrets created
 deployment.apps/redis created
 service/redis created
 deployment.apps/bff created
 service/bff created
 ingress.networking.k8s.io/bff created
 deployment "redis" successfully rolled out
 Waiting for deployment "bff" rollout to finish: 1 of 2 updated replicas are available...
 deployment "bff" successfully rolled out
 bff-574c6d658b-8cz4x        true   kc-lab-1
 bff-574c6d658b-zpkbp        true   kc-lab-2
 redis-568bd7c4-5c5vc        true   kc-lab-2
@@ -0,0 +1,13 @@
 === B-0: 자동구성이 실제로 고른 구현체 ===
  Q1 확인한 사실: "코드에 저장소를 직접 생성하는 Bean 이 없기 때문에,
   어떤 구현체가 실제로 사용되는지는 자동구성 결과까지 확인해야 정확하게 알 수 있다"
  File "<stdin>", line 9
    print(f"    {name:46} {t.rsplit(\".\",1)[-1]}")
                                     ^
 SyntaxError: unexpected character after line continuation character
 === HttpSession 은 어디에 있는가 (서블릿 컨테이너 기본) ===
 === 외부 진입점 ===
  https://app1.hyeonworks.com/  HTTP 200
@@ -0,0 +1,29 @@
 === B-0 — 자동구성이 실제로 고른 구현체 ===
  컨텍스트: keycloak-bff
  전체 빈 수: 321
  --- 세션 · 토큰 저장소 관련 ---
    authorizedClientManager                        -> AuthorizedClientServiceOAuth2AuthorizedClientManager
    authorizedClientManagerRegistrar               -> OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerRegistrar
    authorizedClientRepository                     -> AuthenticatedPrincipalOAuth2AuthorizedClientRepository
    authorizedClientService                        -> InMemoryOAuth2AuthorizedClientService
    org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientConfigurations$OAuth2AuthorizedClientServiceConfiguration -> OAuth2ClientConfigurations$OAuth2AuthorizedClientServiceConfiguration
    org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerConfiguration -> OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerConfiguration
  --- OAuth2 클라이언트 관련 전체 ---
    authorizedClientManager                        -> AuthorizedClientServiceOAuth2AuthorizedClientManager
    authorizedClientManagerRegistrar               -> OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerRegistrar
    authorizedClientRepository                     -> AuthenticatedPrincipalOAuth2AuthorizedClientRepository
    authorizedClientService                        -> InMemoryOAuth2AuthorizedClientService
    clientRegistrationRepository                   -> InMemoryClientRegistrationRepository
    org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientAutoConfiguration -> OAuth2ClientAutoConfiguration
    org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientConfigurations$ClientRegistrationRepositoryConfiguration -> OAuth2ClientConfigurations$ClientRegistrationRepositoryConfiguration
    org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientConfigurations$OAuth2AuthorizedClientServiceConfiguration -> OAuth2ClientConfigurations$OAuth2AuthorizedClientServiceConfiguration
    org.springframework.boot.autoconfigure.security.oauth2.client.servlet.OAuth2ClientWebSecurityAutoConfiguration -> OAuth2ClientWebSecurityAutoConfiguration
    org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration -> OAuth2ClientConfiguration
    org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerConfiguration -> OAuth2ClientConfiguration$OAuth2AuthorizedClientManagerConfiguration
    org.springframework.security.config.annotation.web.configuration.OAuth2ClientConfiguration$OAuth2ClientWebMvcSecurityConfiguration -> OAuth2ClientConfiguration$OAuth2ClientWebMvcSecurityConfiguration
    spring.security.oauth2.client-org.springframework.boot.autoconfigure.security.oauth2.client.OAuth2ClientProperties -> OAuth2ClientProperties
  --- Redis / Spring Session 이 구성되었는가 ---
    ★ 없음 — Redis 도 Spring Session 도 구성되지 않았다
@@ -0,0 +1,18 @@
 # B-0 — BFF·Redis 배포와 자동구성 확인 증거
 2026-09-04 14:20–14:50 KST
 해설: [`docs/experiment-b0-bff-redis-deploy.md`](../../experiment-b0-bff-redis-deploy.md)
 | 파일 | 무엇을 보여주는가 |
 |---|---|
 | `01-deploy.txt` | 배포 전 자원, Redis·BFF 롤아웃, 두 노드에 하나씩 배치됨 |
 | `02-autoconfiguration.txt` | 첫 조회 시도(파싱 실패)와 **외부 진입점 `HTTP 200`** |
 | `03-beans-analysis.txt` | **B-0 의 답** — `InMemoryOAuth2AuthorizedClientService`, `AuthenticatedPrincipalOAuth2AuthorizedClientRepository`, **Redis·Spring Session 없음** |
 | `b0-bff-login-success-single-replica.png` | replica 1 에서 로그인 성공한 BFF 화면 |
 | `b0-bff-token-boundary.png` | `/bff/token-boundary` — `principal: labuser`, `accessTokenStoredOnServer: true`, **`browserTokenCount: 0`** |
 ## 핵심 세 줄
 1. **`AuthenticatedPrincipalOAuth2AuthorizedClientRepository`** — 조회 키가 principal 이고 session ID 가 없다. Q1·Q3 문제의 기제가 이 빈 하나에 있다.
 2. **Redis 를 붙여도 그건 안 고쳐진다.** 저장소 공유와 조회 키는 다른 문제다.
 3. **replica 2개에서는 로그인 자체가 실패한다.** 인가 코드 흐름의 왕복 두 번이 같은 인스턴스로 가야 하는데, 인가 요청이 인스턴스 메모리에 있다.
@@ -0,0 +1,5 @@
 deployment.apps/bff configured
 deployment "bff" successfully rolled out
 bff-576d869c6d-bshvl   true   kc-lab-2
 bff-695646ddb-kzs9k    true   kc-lab-1
 bff-695646ddb-vjqzf    true   kc-lab-2
@@ -0,0 +1,64 @@
 === B-1 — Redis 를 붙인 뒤 자동구성이 실제로 바뀌었는가 ===
  빈 수: 321 → 402  (+81)
  --- 세션 저장소 관련 (새로 생긴 것) ---
    ★ cookieSerializer                           -> DefaultCookieSerializer
    ★ org.springframework.boot.autoconfigure.session.RedisSessionConfiguration -> RedisSessionConfiguration
    ★ org.springframework.boot.autoconfigure.session.RedisSessionConfiguration$DefaultRedisSessionConfiguration -> RedisSessionConfiguration$DefaultRedisSessionConfiguration
    ★ org.springframework.boot.autoconfigure.session.SessionAutoConfiguration -> SessionAutoConfiguration
    ★ org.springframework.boot.autoconfigure.session.SessionAutoConfiguration$ServletSessionConfiguration -> SessionAutoConfiguration$ServletSessionConfiguration
    ★ org.springframework.boot.autoconfigure.session.SessionAutoConfiguration$ServletSessionConfiguration$RememberMeServicesConfiguration -> SessionAutoConfiguration$ServletSessionConfiguration$RememberMeServicesConfiguration
    ★ org.springframework.boot.autoconfigure.session.SessionAutoConfiguration$ServletSessionConfiguration$ServletSessionRepositoryConfiguration -> SessionAutoConfiguration$ServletSessionConfiguration$ServletSessionRepositoryConfiguration
    ★ org.springframework.boot.autoconfigure.session.SessionRepositoryFilterConfiguration -> SessionRepositoryFilterConfiguration
    ★ org.springframework.session.config.annotation.web.http.SpringHttpSessionConfiguration -> SpringHttpSessionConfiguration
    ★ org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration -> RedisHttpSessionConfiguration
    ★ rememberMeServicesCookieSerializerCustomizer -> SessionAutoConfiguration$ServletSessionConfiguration$RememberMeServicesConfiguration$$Lambda/0x00007f364e69fa60
    ★ sessionEventHttpSessionListenerAdapter     -> SessionEventHttpSessionListenerAdapter
    ★ sessionRepository                          -> RedisSessionRepository
    ★ sessionRepositoryFilterRegistration        -> DelegatingFilterProxyRegistrationBean
    ★ spring.session-org.springframework.boot.autoconfigure.session.SessionProperties -> SessionProperties
    ★ spring.session.redis-org.springframework.boot.autoconfigure.session.RedisSessionProperties -> RedisSessionProperties
    ★ springBootSessionRepositoryCustomizer      -> RedisSessionConfiguration$DefaultRedisSessionConfiguration$$Lambda/0x00007f364e6a4a68
    ★ springSessionRepositoryFilter              -> SessionRepositoryFilter
  --- OAuth2 authorized client — 바뀌었는가? ---
    authorizedClientService
      before: InMemoryOAuth2AuthorizedClientService
      after : InMemoryOAuth2AuthorizedClientService    그대로 — Redis 로 안 옮겨졌다
    authorizedClientRepository
      before: AuthenticatedPrincipalOAuth2AuthorizedClientRepository
      after : AuthenticatedPrincipalOAuth2AuthorizedClientRepository    그대로 — Redis 로 안 옮겨졌다
    authorizedClientManager
      before: AuthorizedClientServiceOAuth2AuthorizedClientManager
      after : AuthorizedClientServiceOAuth2AuthorizedClientManager    그대로 — Redis 로 안 옮겨졌다
  --- Redis 연결 빈 (새로 생긴 것) ---
    ★ keyValueMappingContext                     -> RedisMappingContext
    ★ lettuceMetrics                             -> LettuceMetricsAutoConfiguration$$Lambda/0x00007f364e56f4d0
    ★ org.springframework.boot.actuate.autoconfigure.data.redis.RedisHealthContributorAutoConfiguration -> RedisHealthContributorAutoConfiguration
    ★ org.springframework.boot.actuate.autoconfigure.data.redis.RedisReactiveHealthContributorAutoConfiguration -> RedisReactiveHealthContributorAutoConfiguration
    ★ org.springframework.boot.actuate.autoconfigure.metrics.redis.LettuceMetricsAutoConfiguration -> LettuceMetricsAutoConfiguration
    ★ org.springframework.boot.autoconfigure.data.redis.LettuceConnectionConfiguration -> LettuceConnectionConfiguration
    ★ org.springframework.boot.autoconfigure.data.redis.RedisAutoConfiguration -> RedisAutoConfiguration
    ★ org.springframework.boot.autoconfigure.data.redis.RedisReactiveAutoConfiguration -> RedisReactiveAutoConfiguration
    ★ org.springframework.boot.autoconfigure.data.redis.RedisRepositoriesAutoConfiguration -> RedisRepositoriesAutoConfiguration
    ★ org.springframework.boot.autoconfigure.session.RedisSessionConfiguration -> RedisSessionConfiguration
    ★ org.springframework.boot.autoconfigure.session.RedisSessionConfiguration$DefaultRedisSessionConfiguration -> RedisSessionConfiguration$DefaultRedisSessionConfiguration
    ★ org.springframework.session.data.redis.config.annotation.web.http.RedisHttpSessionConfiguration -> RedisHttpSessionConfiguration
    ★ reactiveRedisTemplate                      -> ReactiveRedisTemplate
    ★ reactiveStringRedisTemplate                -> ReactiveStringRedisTemplate
    ★ redisConnectionDetails                     -> PropertiesRedisConnectionDetails
    ★ redisConnectionFactory                     -> LettuceConnectionFactory
    ★ redisConverter                             -> MappingRedisConverter
    ★ redisCustomConversions                     -> RedisCustomConversions
    ★ redisHealthContributor                     -> RedisReactiveHealthIndicator
    ★ redisKeyValueAdapter                       -> RedisKeyValueAdapter
    ★ redisKeyValueTemplate                      -> RedisKeyValueTemplate
    ★ redisMappingConfiguration#0                -> MappingConfiguration
    ★ redisReferenceResolver                     -> ReferenceResolverImpl
    ★ redisTemplate                              -> RedisTemplate
    ★ sessionRepository                          -> RedisSessionRepository
    ★ spring.data.redis-org.springframework.boot.autoconfigure.data.redis.RedisProperties -> RedisProperties
    ★ spring.session.redis-org.springframework.boot.autoconfigure.session.RedisSessionProperties -> RedisSessionProperties
    ★ springBootSessionRepositoryCustomizer      -> RedisSessionConfiguration$DefaultRedisSessionConfiguration$$Lambda/0x00007f364e6a4a68
    ★ stringRedisTemplate                        -> StringRedisTemplate
@@ -0,0 +1,21 @@
 === Redis 에 무엇이 들어 있는가 ===
 bff:session:sessions:8963b6de-3564-4775-9ccd-1ee9616b83ae
  총 키 수: 1
 === 세션 키의 내용 — refresh token 이 있는가 (Q3 검증 2번) ===
  키: bff:session:sessions:8963b6de-3564-4775-9ccd-1ee9616b83ae
  타입: hash
    필드: sessionAttr:SPRING_SECURITY_CONTEXT
    필드: sessionAttr:SPRING_SECURITY_SAVED_REQUEST
    필드: sessionAttr:SPRING_SECURITY_LAST_EXCEPTION
    필드: sessionAttr:org.springframework.security.oauth2.client.web.HttpSessionOAuth2AuthorizationRequestRepository.AUTHORIZATION_REQUEST
    필드: lastAccessedTime
    필드: maxInactiveInterval
    필드: creationTime
 === 필드 값에 토큰 문자열이 보이는가 ===
 1) "sessionAttr:SPRING_SECURITY_CONTEXT"
 2) "\xac\xed\x00\x05sr\x00=org.springframework.security.core.context.SecurityContextImpl\x00\x00\x00\x00\x00\x00\x02l\x02\x00\x01L\x00\x0eauthenticationt\x002Lorg/springframework/security/core/Authentication;xpsr\x00Sorg.springframework.security.oauth2.client.authentication.OAuth2AuthenticationToken\x00\x00\x00\x00\x00\x00\x02l\x02\x00\x02L\x00\x1eauthorizedClientRegistrationIdt\x00\x12Ljava/lang/String;L\x00\tprincipalt\x00:Lorg/springframework/security/oauth2/core/user/OAuth2User;xr\x00Gorg.springframework.security.authentication.AbstractAuthenticationToken\xd3\xaa(~nGd\x0e\x02\x00\x03Z\x00\rauthenticatedL\x00\x0bauthoritiest\x00\x16Ljava/util/Collection;L\x00\adetailst\x00\x12Ljava/lang/Object;xp\x01sr\x00&java.util.Collections$UnmodifiableList\xfc\x0f%1\xb5\xec\x8e\x10\x02\x00\x01L\x00\x04listt\x00\x10Ljava/util/List;xr\x00,java.util.Collect
 === TTL (Q3 검증 3번 — session TTL) ===
  TTL: 1772 초
@@ -0,0 +1,18 @@
 # B-1 — Redis 세션 저장소 전환 증거
 2026-09-04 14:50–15:05 KST
 해설: [`docs/experiment-b1-redis-session-store.md`](../../experiment-b1-redis-session-store.md)
 | 파일 | 무엇을 보여주는가 |
 |---|---|
 | `01-servicelinks-trap.txt` | `enableServiceLinks: false` 적용 후 롤아웃 성공 — 쿠버네티스가 주입한 `REDIS_PORT=tcp://...` 가 설정을 덮어쓴 문제 |
 | `02-autoconfig-after.txt` | **핵심** — 빈 321→402(+81). `sessionRepository → RedisSessionRepository` 로 바뀌었지만 **`authorizedClientService` 는 `InMemory` 그대로** |
 | `03-redis-contents.txt` | Redis 키 1개, 필드는 `SPRING_SECURITY_CONTEXT` 뿐. **토큰 없음.** Java 직렬화(`\xac\xed`), TTL 1772초 |
 | `b1-login-works-two-replicas.png` | 전환 직후 `accessTokenStoredOnServer: false` |
 | `b1-token-boundary-after-redis.png` | 파드 전면 교체 후 — `principal: labuser` 는 살아남고 토큰만 사라진 상태 |
 ## 핵심 세 줄
 1. **세션은 옮겨졌고 토큰은 안 옮겨졌다.** 빈 81개가 늘었는데 authorized client 관련은 하나도 안 바뀌었다.
 2. **refresh token 은 Redis 에 평문으로 있는 게 아니라 아예 없다.** 암호화를 고민하기 전에 이걸 알아야 한다.
 3. **"로그인은 되어 있는데 아무것도 못 하는" 상태가 만들어진다** — 완전 로그아웃보다 나쁘다.
@@ -0,0 +1,283 @@
 # B-0 — 자동구성은 실제로 무엇을 골랐는가 (그리고 배포에서 겪은 것들)
 브랜치 `feature/keycloak-b0-bff-redis-deploy` ·
 증거 [`docs/evidence/b0-bff-redis-deploy/`](evidence/b0-bff-redis-deploy/) ·
 2026-09-04 14:20–14:50 KST
 **Q1 이 직접 요구한 확인이다.**
 > 코드에 저장소를 직접 생성하는 Bean 이 없기 때문에, 어떤 구현체가 실제로
 > 사용되는지는 **Spring Boot 의 자동구성 결과까지 확인해야** 정확하게 알 수 있다.
 ---
 ## 0. 결론부터
 ```
 authorizedClientService      -> InMemoryOAuth2AuthorizedClientService
 authorizedClientRepository   -> AuthenticatedPrincipalOAuth2AuthorizedClientRepository
 authorizedClientManager      -> AuthorizedClientServiceOAuth2AuthorizedClientManager
 clientRegistrationRepository -> InMemoryClientRegistrationRepository
 SessionRepository            -> 없음 (서블릿 컨테이너 in-memory)
 Redis / Spring Session       -> ★ 없음
 ```
 **추측이 맞았지만, 추측으로 두면 안 되는 이유가 두 번째 줄에 있다.**
 `AuthenticatedPrincipalOAuth2AuthorizedClientRepository` — 이름이 곧 설명이다.
 **"인증된 주체(principal) 기준"** 으로 authorized client 를 찾는다.
 **session ID 가 아니다.** Q1·Q3 가 지적한 "같은 사용자의 여러 브라우저가 같은
 token 을 공유한다"는 문제의 **기제가 이 빈 하나에 들어 있다.**
 그리고 배포하자마자 **Q1 의 문제가 실험을 시작하기도 전에 나타났다** —
 replica 2개에서는 **로그인 자체가 실패한다.**
 ---
 ## 1. 배포에서 겪은 문제 다섯 가지
 ### 문제 ① — `bff/` 가 소스 없이 빌드 산출물만 있었다
 ```
 bff/target/classes/...   9개 파일
 bff/src/                 없음
 ```
 `.gitignore` 에 `target/` 이 없어 클래스 파일만 커밋되어 있었다.
 소스는 다른 브랜치에 있었다.
 ```bash
 git checkout origin/develop-keycloak-pattern3 -- bff/
 ```
 ### 문제 ② — YAML 중복 키로 빌드가 깨졌다
 actuator 를 열려고 `management:` 아래에 `endpoint:` 블록을 **하나 더** 넣었다.
 이미 있는데.
 ```
 org.yaml.snakeyaml.constructor.SafeConstructor.processDuplicateKeys
 ```
 **Docker 빌드 로그가 `tail` 로 잘려 원인이 안 보였다.** `--progress=plain` 으로
 전체를 받아서야 스택트레이스에서 `processDuplicateKeys` 를 찾았다.
 ```bash
 docker build --progress=plain -t keycloak-pattern-bff:lab . > /tmp/build.log 2>&1
 grep -nE "Tests run|Caused by|\.java:[0-9]" /tmp/build.log
 ```
 > **빌드 실패는 마지막 15줄에 안 들어 있는 경우가 많다.** 전체를 파일로 받는다.
 ### 문제 ③ — 환경변수에 기본값을 안 줘서 테스트가 죽었다
 `${KC_ISSUER_EXTERNAL}` 처럼 기본값 없이 쓰면 **테스트에서 컨텍스트가 안 뜬다.**
 테스트는 그 환경변수를 모른다.
 ```yaml
 authorization-uri: ${KC_ISSUER_EXTERNAL:http://localhost:8080/realms/keycloak-patterns}/protocol/openid-connect/auth
 ```
 ### 문제 ④ — actuator 가 인증에 막혀 있었다
 `/actuator/beans` 를 부르면 `200` 이 왔는데, **Keycloak 로그인 페이지**였다.
 `-L` 로 리다이렉트를 따라간 결과였다.
 ```java
 "/actuator/health",
 "/actuator/health/**",
 // 실험대 전용 — 운영에서는 절대 열지 않는다
 "/actuator/**"
 ```
 > **`200` 이 곧 성공은 아니다.** 무엇이 왔는지 봐야 한다.
 ### 문제 ⑤ — 큰 응답이 프록시에서 `Bad Gateway`
 `/actuator/beans` 는 117KB 다. nginx → Traefik 을 거치면서 실패했다.
 ```
 $ curl https://app1.hyeonworks.com/actuator/beans
 Bad Gateway
 ```
 파드 안에서 직접 받아 해결했다. **alpine 기반 JRE 이미지에 `wget` 이 있다.**
 ```bash
 kubectl -n keycloak-lab exec <bff-pod> -- wget -qO- http://localhost:8083/actuator/beans
 ```
 ---
 ## 2. 배포 구성
 ```
   브라우저 ──https──▶ nginx ──▶ Traefik ──▶ bff (2 replica)
                                              │
                                              ├──▶ Keycloak  (realm: keycloak-patterns)
                                              └──▶ echo      (resource server 대역)
   redis  ── kc-lab-2 (postgres 와 같은 노드)  ← 아직 연결하지 않았다
 ```
 **Redis 는 배포만 하고 BFF 에 연결하지 않았다.** B-0 의 질문이 "아무것도 주지
 않았을 때 자동구성이 무엇을 고르는가"이므로, 아무것도 주지 않은 상태를 먼저
 측정해야 한다.
 ### Keycloak realm 준비 (kcadm)
 ```bash
 kubectl -n keycloak-lab exec keycloak-0 -- /opt/keycloak/bin/kcadm.sh config credentials \
  --server http://localhost:8080 --realm master --user admin --password <pw>
 kubectl -n keycloak-lab exec keycloak-0 -- /opt/keycloak/bin/kcadm.sh create realms \
  -s realm=keycloak-patterns -s enabled=true -s accessTokenLifespan=60
 kubectl -n keycloak-lab exec keycloak-0 -- /opt/keycloak/bin/kcadm.sh create clients -r keycloak-patterns \
  -s clientId=bff-confidential -s publicClient=false -s secret=bff-lab-secret \
  -s 'redirectUris=["https://app1.hyeonworks.com/*"]'
 ```
 **`accessTokenLifespan=60`** 으로 둔 것은 B-3(refresh 경쟁)을 위해서다.
 만료를 기다리는 시간이 짧아야 재현이 된다.
 ### 브라우저용 URL 과 백채널 URL 을 분리했다
 ```yaml
 authorization-uri: ${KC_ISSUER_EXTERNAL}/protocol/openid-connect/auth   # 브라우저가 간다
 token-uri:         ${KC_ISSUER_INTERNAL}/protocol/openid-connect/token  # BFF 가 서버끼리
 ```
 ```yaml
 - name: KC_ISSUER_EXTERNAL
  value: https://auth.hyeonworks.com/realms/keycloak-patterns
 - name: KC_ISSUER_INTERNAL
  value: http://keycloak.keycloak-lab.svc:8080/realms/keycloak-patterns
 ```
 **2홉 헤더 실험에서 배운 것이 그대로 쓰인다** — 브라우저가 보는 이름과
 서버가 부르는 주소는 다르고, 섞으면 리다이렉트가 깨진다.
 `SERVER_FORWARD_HEADERS_STRATEGY=native` 도 같은 이유다. 없으면 Spring 이
 `redirect_uri` 를 `http://` 로 만들어 Keycloak 이 거부한다.
 ---
 ## 3. 동작 확인 — 브라우저 증거
 ![로그인 성공](evidence/b0-bff-redis-deploy/b0-bff-login-success-single-replica.png)
 ![token 경계](evidence/b0-bff-redis-deploy/b0-bff-token-boundary.png)
 ```json
 {"pattern":"AP3-backend-for-frontend","principal":"labuser",
 "accessTokenStoredOnServer":true,"refreshTokenStoredOnServer":true,
 "browserTokenCount":0,"csrfProtectionEnabled":true}
 ```
 **BFF 패턴이 성립한다** — 브라우저에 토큰이 0개이고, 서버가 access/refresh 를
 들고 있다.
 ---
 ## 4. B-0 의 답 — 자동구성 결과
 전체 빈 321개 중 관련된 것들이다.
 | 빈 | 구현체 | 뜻 |
 |---|---|---|
 | `authorizedClientService` | **`InMemoryOAuth2AuthorizedClientService`** | **프로세스 메모리.** 재시작하면 사라진다 |
 | `authorizedClientRepository` | **`AuthenticatedPrincipalOAuth2AuthorizedClientRepository`** | **principal 기준 조회.** session ID 가 없다 |
 | `authorizedClientManager` | `AuthorizedClientServiceOAuth2AuthorizedClientManager` | **service**(공유) 를 쓴다 |
 | `clientRegistrationRepository` | `InMemoryClientRegistrationRepository` | 설정에서 읽은 것 |
 | SessionRepository | **없음** | Tomcat 의 기본 `StandardSession` |
 | Redis / Spring Session | **없음** | 의존성 자체가 없다 |
 ### `AuthenticatedPrincipalOAuth2AuthorizedClientRepository` 가 핵심이다
 ```
   요청이 인증되어 있으면
     └─▶ OAuth2AuthorizedClientService 에 위임
            └─▶ 키: (clientRegistrationId, principalName)
                        └─ session ID 가 없다   ★
   인증되어 있지 않으면
     └─▶ HttpSession 에 임시 보관
 ```
 **같은 사용자가 두 브라우저에서 로그인하면 principalName 이 같으므로
 같은 항목을 본다.** Q1 의 미지수 3 과 Q3 의 제약이 여기서 나온다.
 > **Redis 를 붙여도 이건 안 고쳐진다.** 저장소를 공유해도 **키에 session ID 가
 > 없기 때문**이다. Q1 이 "Session Store 를 공유 저장소로 바꾸는 것만으로는
 > 충분하지 않다"고 쓴 이유다.
 ---
 ## 5. 예상 못 한 것 — **replica 2개에서 로그인 자체가 안 된다**
 배포 직후 브라우저에서 로그인하니 `/login?error` 로 떨어졌다.
 BFF 로그에는 아무 오류도 없었다 (Spring Security 는 로그인 실패를 DEBUG 로만 남긴다).
 **가설** — 인가 요청(state, PKCE verifier)은 `HttpSession` 에 저장된다.
 그런데 그 세션은 **인스턴스 메모리**다. 콜백이 다른 replica 로 가면 저장된
 인가 요청이 없어 실패한다.
 **검증** — replica 를 1로 줄이고 다시 시도했다.
 ```bash
 kubectl -n keycloak-lab scale deployment/bff --replicas=1
 ```
 **로그인이 성공했다.** 가설 확정.
 ```
   replica 2 + 스티키 없음 → 로그인 실패 (콜백이 다른 인스턴스로)
   replica 1              → 로그인 성공
 ```
 > **Q1 의 문제가 실험을 시작하기도 전에 나타났다.**
 > "다중 인스턴스에서 어떻게 운영할 것인가"는 **로그인한 뒤의 문제가 아니라
 > 로그인 자체의 문제**다. 인가 코드 흐름은 **왕복 두 번**이고, 두 번 다 같은
 > 인스턴스로 가야 한다.
 >
 > 이건 B-2 의 검증 1번("한쪽에서 로그인한 뒤 다른 인스턴스로 요청")보다
 > **앞선 단계**다. 로그인이 끝나야 그 검증을 할 수 있는데, 로그인부터 막힌다.
 ---
 ## 6. 재현 절차 (명령어)
 ```bash
 # 1. 소스 가져오기 (target/ 만 커밋되어 있었다)
 git checkout origin/develop-keycloak-pattern3 -- bff/
 # 2. 빌드 — 실패하면 전체 로그를 파일로
 docker build --progress=plain -t keycloak-pattern-bff:lab bff/ > /tmp/build.log 2>&1
 grep -nE "Tests run|Caused by" /tmp/build.log
 # 3. 두 노드에 적재 (레지스트리 없음 → imagePullPolicy: Never)
 docker save keycloak-pattern-bff:lab | ssh test-server "ssh kc-lab-1 'sudo k3s ctr images import -'"
 docker save keycloak-pattern-bff:lab | ssh test-server "ssh kc-lab-2 'sudo k3s ctr images import -'"
 # 4. realm · client · user
 kubectl -n keycloak-lab exec keycloak-0 -- /opt/keycloak/bin/kcadm.sh create realms -s realm=keycloak-patterns ...
 # 5. 배포
 kubectl apply -f deploy/lab/k8s/bff-redis.yaml
 # 6. 자동구성 결과 — 파드 안에서 (프록시는 큰 응답에서 502)
 kubectl -n keycloak-lab exec <bff-pod> -- wget -qO- http://localhost:8083/actuator/beans > beans.json
 python3 -c "import json;d=json.load(open('beans.json'));[print(n,'->',i['type']) for n,i in
  list(d['contexts'].values())[0]['beans'].items() if 'AuthorizedClient' in i['type']]"
 ```
 ---
 ## 7. 다음 실험에 남기는 것
 | 실험 | 이 실험이 준 것 |
 |---|---|
 | **B-1** 저장소 결정 | **전환 후 이 빈들이 바뀌는지 다시 찍는다.** "Redis 붙였다"고 믿는데 자동구성이 안 걸리는 경우가 흔하다 |
 | **B-2** 다중 인스턴스 | **로그인 자체가 실패한다**는 것이 이미 관측됐다. 그것이 검증 0번이다 |
 | **B-3** refresh 경쟁 | `accessTokenLifespan=60` 으로 realm 을 만들어뒀다 |
 | 운영 | actuator `beans`/`env` 는 **내부 구조를 그대로 드러낸다.** 실험대에서만 연다 |
@@ -0,0 +1,297 @@
 # B-1 — Redis 를 붙이면 무엇이 옮겨지고 무엇이 안 옮겨지는가 → Q3
 브랜치 `feature/keycloak-b1-redis-session-store` ·
 증거 [`docs/evidence/b1-redis-session-store/`](evidence/b1-redis-session-store/) ·
 2026-09-04 14:50–15:05 KST
 선행: [`B-0`](experiment-b0-bff-redis-deploy.md)
 **대응 질문** — [Q3 · BFF의 Session과 OAuth2AuthorizedClient를 어디에 저장할 것인가](https://hyeonworks.com/questions/bff-session-authorized-client-store)
 ---
 ## 0. 결론부터
 | | before | after | |
 |---|---|---|---|
 | `sessionRepository` | (없음, Tomcat 기본) | **`RedisSessionRepository`** | **옮겨졌다** |
 | `authorizedClientService` | `InMemoryOAuth2AuthorizedClientService` | **`InMemoryOAuth2AuthorizedClientService`** | **그대로다** |
 | `authorizedClientRepository` | `AuthenticatedPrincipalOAuth2AuthorizedClientRepository` | **동일** | **그대로다** |
 그 결과 사용자에게는 이렇게 보인다.
 ```json
 {"principal":"labuser",                     ← 로그인은 되어 있다
 "accessTokenStoredOnServer":false,         ← 그런데 토큰이 없다
 "refreshTokenStoredOnServer":false,
 "browserTokenCount":0}
 ```
 **"로그인은 되어 있는데 아무것도 못 하는" 상태**가 만들어진다.
 Q1 이 *"Session Store 를 공유 저장소로 변경하는 것만으로는 충분하지 않다"* 고
 쓴 것의 실물이다.
 ---
 ## 1. 문제 ① — 쿠버네티스가 내 환경변수를 덮어썼다
 배포하자마자 파드가 안 떴다.
 ```
 Failed to bind properties under 'spring.data.redis.port' to int:
    Property: spring.data.redis.port
    Value: "${REDIS_PORT:6379}"
    Reason: failed to convert java.lang.String to int
            (caused by NumberFormatException: For input string: "tcp://10.43.57.116:6379")
 ```
 **쿠버네티스가 `REDIS_PORT=tcp://10.43.57.116:6379` 를 주입했다.**
 ### 개념 — Service Links
 쿠버네티스는 같은 네임스페이스의 **모든 Service 마다** Docker link 시절의
 환경변수를 파드에 자동으로 넣는다.
 ```
   Service 이름이 redis 이면
     REDIS_SERVICE_HOST=10.43.57.116
     REDIS_SERVICE_PORT=6379
     REDIS_PORT=tcp://10.43.57.116:6379        ← 이게 문제
     REDIS_PORT_6379_TCP=tcp://10.43.57.116:6379
     REDIS_PORT_6379_TCP_ADDR=10.43.57.116
     ...
 ```
 **`<SVCNAME>_PORT` 는 포트 번호가 아니라 URL 형태다.** 이름이 겹치면
 애플리케이션 설정이 조용히 오염된다.
 ```yaml
 spec:
  enableServiceLinks: false      # 근본 처방
 ```
 > **환경변수 이름을 바꿔 피할 수도 있다.** 그러면 다음 사람이 같은 함정에
 > 다시 빠진다. **주입 자체를 끄는 쪽**을 골랐다.
 >
 > 이 함정은 Service 이름과 환경변수 이름이 겹칠 때만 나타나므로,
 > `REDIS`, `POSTGRES`, `MYSQL` 처럼 **흔한 이름일수록 위험하다.**
 ## 문제 ② — 테스트가 Redis 를 찾다가 죽었다
 `spring-session-data-redis` 를 넣으면 컨텍스트 기동 시 Redis 에 붙으려 한다.
 테스트에는 Redis 가 없다.
 ```java
@SpringBootTest(properties = {
    "KEYCLOAK_CLIENT_SECRET=test-only-secret",
    // 테스트는 Redis 를 띄우지 않는다
    "spring.session.store-type=none",
 })
 ```
 ## 문제 ③ — 리소스 서버가 아예 없었다
 API 호출이 `500` 이었다. 원인은 토큰이 아니었다.
 ```
 java.nio.channels.UnresolvedAddressException
 ```
 `RESOURCE_API_BASE_URL=http://echo.keycloak-lab.svc:8080` 인데 `echo` 는
 **`header-lab` 네임스페이스의 8081** 이었다. 배포조차 되어 있지 않았다.
 > **500 을 보고 "토큰이 없어서"라고 읽을 뻔했다.** 로그를 보니 DNS 였다.
 > A층에서 반복해서 배운 것 — **증상과 원인을 붙이기 전에 로그를 본다.**
 ```yaml
 # 다른 네임스페이스의 서비스는 <svc>.<ns>.svc 로 부른다
 value: http://echo.header-lab.svc:8081
 ```
 ---
 ## 2. 자동구성이 실제로 바뀌었는가 — B-0 의 방법을 다시 쓴다
 ```bash
 kubectl -n keycloak-lab exec <bff-pod> -- wget -qO- http://localhost:8083/actuator/beans
 ```
 ```
  빈 수: 321 → 402  (+81)
  --- 세션 저장소 (새로 생긴 것) ---
    ★ sessionRepository                    -> RedisSessionRepository
    ★ springSessionRepositoryFilter        -> SessionRepositoryFilter
    ★ RedisHttpSessionConfiguration
    ★ cookieSerializer                     -> DefaultCookieSerializer
  --- OAuth2 authorized client ---
    authorizedClientService
      before: InMemoryOAuth2AuthorizedClientService
      after : InMemoryOAuth2AuthorizedClientService    그대로 — Redis 로 안 옮겨졌다
    authorizedClientRepository
      before: AuthenticatedPrincipalOAuth2AuthorizedClientRepository
      after : AuthenticatedPrincipalOAuth2AuthorizedClientRepository   그대로
 ```
 **빈 81개가 늘었는데 authorized client 는 하나도 안 바뀌었다.**
 > **"Redis 를 붙였다"가 "상태가 공유된다"를 뜻하지 않는다.**
 > 무엇이 옮겨졌는지 **찍어서 확인**해야 한다. B-0 을 실험으로 만든 이유다.
 ---
 ## 3. Redis 안에 무엇이 들어갔는가 → Q3 검증 2번
 ```
 === Redis 키 ===
 bff:session:sessions:8963b6de-3564-4775-9ccd-1ee9616b83ae
  dbsize: 1
 === 필드 ===
  sessionAttr:SPRING_SECURITY_CONTEXT
  sessionAttr:SPRING_SECURITY_SAVED_REQUEST
  sessionAttr:SPRING_SECURITY_LAST_EXCEPTION
  sessionAttr:...HttpSessionOAuth2AuthorizationRequestRepository.AUTHORIZATION_REQUEST
  lastAccessedTime / maxInactiveInterval / creationTime
 === TTL ===
  1772 초        ← spring.session.timeout=30m 과 일치
 ```
 ### **refresh token 은 Redis 에 없다**
 Q3 는 *"저장소를 직접 열어 refresh token 이 평문으로 남는지 확인한다"* 를
 검증 항목으로 두었다. 답은 더 앞에 있었다 — **애초에 들어가지 않는다.**
 ```
   Application Session  ──▶ Redis        (인증 상태, principal, 인가 요청)
   OAuth2AuthorizedClient ─▶ 프로세스 메모리  (access token, refresh token)
 ```
 **"토큰 암호화를 어떻게 할까"를 고민하기 전에, 토큰이 그 저장소에 가지도
 않는다는 것을 먼저 알아야 한다.**
 ### 직렬화는 Java 네이티브다
 ```
 \xac\xed\x00\x05sr\x00=org.springframework.security.core.context.SecurityContextImpl
 ```
 `\xac\xed` 는 **Java 직렬화 매직 넘버**다. JSON 이 아니다.
 | 결과 | |
 |---|---|
 | 사람이 못 읽는다 | 운영 중 디버깅이 어렵다 |
 | **클래스 버전에 묶인다** | 애플리케이션을 올리면 **기존 세션이 역직렬화에 실패**할 수 있다 |
 | 역직렬화 취약점 | 신뢰할 수 없는 데이터가 들어오면 위험한 형식이다 |
 **D-2(버전 업그레이드)에서 이것이 다시 나온다** — Spring Security 버전이
 바뀌면 Redis 에 남은 세션이 깨질 수 있다.
 ---
 ## 4. 사용자에게 보이는 결과 — 가장 중요한 부분
 ![Redis 전환 후 token-boundary](evidence/b1-redis-session-store/b1-token-boundary-after-redis.png)
 ```json
 {"pattern":"AP3-backend-for-frontend",
 "principal":"labuser",                  ← 세션은 Redis 에서 복원되었다
 "accessTokenStoredOnServer":false,      ← 토큰은 사라졌다
 "refreshTokenStoredOnServer":false,
 "browserTokenCount":0,
 "csrfProtectionEnabled":true}
 ```
 **파드가 전부 교체됐는데 로그인 상태는 살아남았다.** Redis 덕분이다.
 **그런데 토큰은 같이 살아남지 못했다.** 인스턴스 메모리에 있었으니까.
 ```
   사용자 관점:  로그인되어 있다고 나온다
   실제:        BFF 가 사용자를 대신해 아무것도 못 한다
 ```
 **이것이 "부분적으로만 공유했을 때"의 실패 모양이다.**
 완전히 로그아웃되는 편이 차라리 낫다 — 적어도 사용자가 다시 로그인한다.
 ### B-0 과 나란히 놓으면
 | | B-0 (Redis 없음, replica 1) | **B-1 (Redis 세션, replica 2)** |
 |---|---|---|
 | `principal` | labuser | labuser |
 | `accessTokenStoredOnServer` | **true** | **false** |
 | 파드 재시작 후 | 로그아웃 | **로그인 상태만 남고 토큰은 소실** |
 ---
 ## 5. Q3 검증 항목 대조
 | # | Q3 의 검증 | 결과 |
 |---|---|---|
 | 1 | 인스턴스 두 대에서 로그인 유지·재시작 복구 | **세션은 유지, 토큰은 소실** |
 | 2 | 저장소를 열어 refresh token 이 평문인지 | **평문 이전에 존재하지 않는다** |
 | 3 | session TTL 과 token 만료 어긋남 | TTL 1772초 관측. 토큰 만료(60초)와 **처음부터 어긋나 있다** |
 | 4 | logout 뒤 두 store 잔여 항목 | **B-2 에서 이어서** |
 | 5 | 저장소를 끊었을 때 오류 | **B-5 에서** |
 | 6 | 같은 store vs 분리 | **분리가 기본값이었다** — 고르는 것이 아니라 이미 그렇다 |
 | 7 | 저장소 지연이 화면 지연으로 | **B-2 이후** |
 **6번의 답이 이 실험의 요지다.** "두 상태를 같은 저장소에 둘지 나눌지"는
 선택지가 아니라 **이미 나뉘어 있고, 나뉜 채로 두면 깨진다.**
 ---
 ## 6. 그래서 무엇을 해야 하는가
 `OAuth2AuthorizedClientService` 를 공유 저장소로 옮기는 구현이 따로 필요하다.
 | 후보 | |
 |---|---|
 | `JdbcOAuth2AuthorizedClientService` | Spring Security 기본 제공. **PostgreSQL 이 이미 있다** |
 | 직접 구현 (Redis) | `OAuth2AuthorizedClientService` 인터페이스를 Redis 로 구현 |
 | 세션 안에 넣기 | `HttpSessionOAuth2AuthorizedClientRepository` 를 쓰면 세션과 함께 Redis 로 간다 |
 **세 번째가 흥미롭다** — 조회 키 문제(principal 기준)까지 같이 해결된다.
 세션 단위로 저장되므로 **같은 사용자의 다른 브라우저가 서로를 덮어쓰지 않는다.**
 대신 세션이 커진다.
 **B-2 에서 이 선택지를 비교한다.**
 ---
 ## 7. 재현 절차 (명령어)
 ```bash
 # 1. 의존성 두 개를 함께 넣는다 (하나만 넣으면 조용히 in-memory 로 남는다)
 #    spring-session-data-redis  +  spring-boot-starter-data-redis
 # 2. 테스트는 Redis 를 안 띄우므로 store-type=none 을 준다
 # 3. 배포 — enableServiceLinks: false 를 잊지 말 것
 kubectl apply -f deploy/lab/k8s/bff-redis.yaml
 # 4. 자동구성이 실제로 바뀌었는지 확인 (B-0 의 방법)
 kubectl -n keycloak-lab exec <bff-pod> -- wget -qO- http://localhost:8083/actuator/beans > after.json
 #    sessionRepository 가 RedisSessionRepository 인가
 #    authorizedClientService 는 여전히 InMemory 인가   ← 이쪽이 핵심
 # 5. Redis 를 직접 연다
 kubectl -n keycloak-lab exec deploy/redis -- redis-cli --scan
 kubectl -n keycloak-lab exec deploy/redis -- redis-cli hkeys "bff:session:sessions:<id>"
 kubectl -n keycloak-lab exec deploy/redis -- redis-cli ttl  "bff:session:sessions:<id>"
 # 6. 사용자 관점 확인
 #    브라우저로 https://app1.hyeonworks.com/bff/token-boundary
 ```
 ---
 ## 8. 다음 실험에 남기는 것
 | 실험 | 이 실험이 준 것 |
 |---|---|
 | **B-2** 다중 인스턴스 | **authorized client 를 어디로 옮길지**가 남았다. 세 후보를 비교한다 |
 | **B-3** refresh 경쟁 | 토큰이 공유되어야 경쟁이 재현된다 — **아직 공유되지 않았다** |
 | **D-2** 업그레이드 | **Java 직렬화된 세션**이 버전 변경에 견디는가 |
 | 운영 | `enableServiceLinks: false` — Service 이름과 환경변수 충돌 |
		`@@ -0,0 +1 @@`
							`[ 207ms] [ERROR] Failed to load resource: the server responded with a status of 404 () @ https://app1.hyeonworks.com/favicon.ico:0`
		`@@ -0,0 +1 @@`
							`[ 236ms] [ERROR] Failed to load resource: the server responded with a status of 500 () @ https://app1.hyeonworks.com/bff/api/me:0`
		`@@ -0,0 +1,2 @@`
							[ 7292ms] [ERROR] Access to fetch at 'https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=WWc76H7TY73Fbsdc41B2nRD5exkXqHcohLh4WdJB4AA%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=A4TXweuKS4Y5HdZ63rLJUez1ZOyI2em6zs3OIfTXLFo&code_challenge=wPr8PXG0lcUvie7Wo91YrVMhOUYq0KtEU4PxVJ0_CWA&code_challenge_method=S256' (redirected from 'https://app1.hyeonworks.com/bff/api/me') from origin 'https://app1.hyeonworks.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. @ https://app1.hyeonworks.com/bff/token-boundary:0
							`[ 7293ms] [ERROR] Failed to load resource: net::ERR_FAILED @ https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=WWc76H7TY73Fbsdc41B2nRD5exkXqHcohLh4WdJB4AA%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=A4TXweuKS4Y5HdZ63rLJUez1ZOyI2em6zs3OIfTXLFo&code_challenge=wPr8PXG0lcUvie7Wo91YrVMhOUYq0KtEU4PxVJ0_CWA&code_challenge_method=S256:0`
		`@@ -0,0 +1,2 @@`
							[ 6726ms] [ERROR] Access to fetch at 'https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=GGupuPr3ZklKp8ah99r7h7mNHEq9yTsEWZr85WyXevE%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=rPVvEOvG7rzssAjR7pP67qNvoY2W6ZVpIpKYz1LGoU8&code_challenge=qoKRLRrzB7z9CU_rlaAxJ7UYcRZswyqmDi8PgxmaWM0&code_challenge_method=S256' (redirected from 'https://app1.hyeonworks.com/bff/api/me') from origin 'https://app1.hyeonworks.com' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. @ https://app1.hyeonworks.com/:0
							`[ 6726ms] [ERROR] Failed to load resource: net::ERR_FAILED @ https://auth.hyeonworks.com/realms/keycloak-patterns/protocol/openid-connect/auth?response_type=code&client_id=bff-confidential&scope=openid%20profile%20email&state=GGupuPr3ZklKp8ah99r7h7mNHEq9yTsEWZr85WyXevE%3D&redirect_uri=https://app1.hyeonworks.com/login/oauth2/code/keycloak&nonce=rPVvEOvG7rzssAjR7pP67qNvoY2W6ZVpIpKYz1LGoU8&code_challenge=qoKRLRrzB7z9CU_rlaAxJ7UYcRZswyqmDi8PgxmaWM0&code_challenge_method=S256:0`
		`@@ -0,0 +1 @@`
							`- generic [active] [ref=f28e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":true,\"refreshTokenStoredOnServer\":true,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"`
		`@@ -0,0 +1 @@`
							`- generic [active] [ref=f30e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"`
		`@@ -0,0 +1 @@`
							`- generic [active] [ref=f32e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"`
		`@@ -0,0 +1 @@`
							`- generic [active] [ref=f34e1]: "{\"pattern\":\"AP3-backend-for-frontend\",\"principal\":\"labuser\",\"accessTokenStoredOnServer\":false,\"refreshTokenStoredOnServer\":false,\"browserTokenCount\":0,\"csrfProtectionEnabled\":true}"`