diff --git a/deploy/lab/k8s/traefik-forwarded-headers.yaml b/deploy/lab/k8s/traefik-forwarded-headers.yaml new file mode 100644 index 0000000..7d17369 --- /dev/null +++ b/deploy/lab/k8s/traefik-forwarded-headers.yaml @@ -0,0 +1,42 @@ +# Make Traefik trust the X-Forwarded-* headers that the host nginx sets. +# +# Without this, Traefik rewrites every forwarded header from its own connection, +# which is plain HTTP on port 80. The application then sees scheme=http even +# though the browser connected over TLS. See docs/two-hop-proxy-header-contract.md. +# +# k3s installs Traefik through its bundled HelmChart, so values are overridden +# with a HelmChartConfig rather than by editing the deployment. k3s reconciles +# the chart and recreates the Traefik pod. +# +# kubectl apply -f deploy/lab/k8s/traefik-forwarded-headers.yaml +# kubectl -n kube-system rollout status deploy/traefik --timeout=180s +apiVersion: helm.cattle.io/v1 +kind: HelmChartConfig +metadata: + name: traefik + namespace: kube-system +spec: + valuesContent: |- + ports: + web: + forwardedHeaders: + # Requests arriving from these sources keep their existing + # X-Forwarded-* values instead of having them rewritten. + # + # 10.42.0.0/16 is the pod CIDR. It is required because the traefik + # Service uses externalTrafficPolicy: Cluster, so svclb SNATs the + # traffic and Traefik sees a pod-network address rather than the + # host nginx address. + # + # Trusting the whole pod CIDR means any pod in the cluster could + # forge these headers. That is acceptable in this lab and is the + # reason a production setup would narrow it — see the trade-off + # section in docs/two-hop-proxy-header-contract.md. + trustedIPs: + - 10.42.0.0/16 + - 192.168.122.0/24 + websecure: + forwardedHeaders: + trustedIPs: + - 10.42.0.0/16 + - 192.168.122.0/24