Trust internal CA for Authentik SSO; canonical identity.unkin.net for NetBox (#314)

Authentik is canonical at https://identity.unkin.net, served by the internal
unkin.net CA. Grafana, LiteLLM and NetBox failed OIDC discovery because their
images don't trust that CA (x509: unknown authority); NetBox also still pointed
at the secondary admin host.

- grafana: mount the reflected vault-ca-cert; set generic_oauth `tls_client_ca`.
- litellm: `combine-certs` init builds public+internal CA bundle; `SSL_CERT_FILE`
  + `REQUESTS_CA_BUNDLE` point at it.
- netbox: flip OIDC issuer to identity.unkin.net; same combine bundle for
  python-social-auth (`requests`).
- docs: record the Rancher manual runtime step (issuer + CA in the auth config).

Validated: kustomize build + kubeconform + pre-commit.

https://claude.ai/code/session_015ur3i7D2azsMAWTSVABApv
Reviewed-on: #314
Co-authored-by: Ben Vincent <ben@unkin.net>
Co-committed-by: Ben Vincent <ben@unkin.net>

apps/base/litellm/deployment.yaml

@@ -15,6 +15,23 @@ spec:
       labels:
         app: litellm
     spec:
+      # LiteLLM's SSO client reaches identity.unkin.net, whose cert is signed by
+      # the internal unkin.net CA. Combine the image's public roots with the
+      # reflected vault-ca-cert into one bundle (SSL_CERT_FILE/REQUESTS_CA_BUNDLE
+      # in litellm-env point at it) so internal OIDC and public HTTPS both work.
+      initContainers:
+        - name: combine-certs
+          image: alpine:3
+          command:
+            - sh
+            - -c
+            - cat /etc/ssl/certs/ca-certificates.crt /custom-ca/ca.crt > /combined-certs/ca-certificates.crt
+          volumeMounts:
+            - name: vault-ca-cert
+              mountPath: /custom-ca
+              readOnly: true
+            - name: combined-certs
+              mountPath: /combined-certs
       containers:
         - name: litellm
           image: docker.litellm.ai/berriai/litellm-database:main-stable
@@ -72,8 +89,19 @@ spec:
             - mountPath: /app/config.yaml
               name: config
               subPath: config.yaml
+            - name: combined-certs
+              mountPath: /etc/ssl/combined
+              readOnly: true
       restartPolicy: Always
       volumes:
         - name: config
           configMap:
             name: litellm-config
+        - name: vault-ca-cert
+          secret:
+            secretName: vault-ca-cert
+            items:
+              - key: ca.crt
+                path: ca.crt
+        - name: combined-certs
+          emptyDir: {}

apps/base/litellm/kustomization.yaml

@@ -39,5 +39,9 @@ configMapGenerator:
       - GENERIC_SCOPE=openid email profile litellm_role
       - GENERIC_USER_ROLE_ATTRIBUTE=litellm_role
       - PROXY_BASE_URL=https://litellm.k8s.syd1.au.unkin.net
+      # Trust the internal unkin.net CA (identity.unkin.net) via the combined
+      # bundle assembled by the combine-certs init container.
+      - SSL_CERT_FILE=/etc/ssl/combined/ca-certificates.crt
+      - REQUESTS_CA_BUNDLE=/etc/ssl/combined/ca-certificates.crt
     options:
       disableNameSuffixHash: true