Files
certctl/docs/connector-k8s.md
T
shankar0123 0834bc1ad5 docs: deployment vendor matrix + per-connector deep-dive docs (NGINX + K8s + IIS + Apache + F5)
Phase 14 of the deploy-hardening II master bundle. The procurement-
team headline doc + per-connector operator guides for the top 5
most-deployed connectors.

NEW docs/deployment-vendor-matrix.md (~30 rows):
- Per (connector × vendor-version) status: ✓ / CI / mock / pending / n/a
- Known issues + workarounds + e2e test name reference
- LTS + current-stable scope per frozen decision 0.1
- Quarterly re-pin cadence guidance for sidecar digests
- "How to add a new vendor version" recipe

Per frozen decision 0.14: a (connector × vendor-version) cell is
"verified" only when ALL apply: ≥1 happy-path e2e green; ≥1
specific-quirk test green for that version; operator manual smoke
completed at least once. Cells lacking the third criterion show
"CI" status (auto-tests green but pending operator validation).

Status snapshot at bundle close:
- NGINX 1.25 + 1.27: CI
- Apache 2.4: CI
- HAProxy 2.6 + 2.8 + 3.0: CI
- Traefik 2.x + 3.x: CI
- Caddy 2.x: CI
- Envoy 1.30 + 1.32: CI (file-mode SDS only; gRPC SDS V3-Pro)
- Postfix 3.6 + 3.8: CI
- Dovecot 2.3: CI
- IIS 10 (2019, 2022): pending (Windows-host-only CI)
- F5 v15.1 + v17.0 + v17.5: mock (real-F5 vagrant box documented)
- SSH OpenSSH 8.x + 9.x: CI
- WinCertStore (2019, 2022): pending (Windows-host-only)
- JavaKeystore JDK 11 + 17 + 21: pending
- K8s 1.28 + 1.30 + 1.31: CI

NEW per-connector deep-dive docs:
- docs/connector-nginx.md (~150 lines, 10 quirks documented)
- docs/connector-k8s.md (~110 lines, 10 quirks)
- docs/connector-iis.md (~120 lines, 10 quirks; Windows-host-only
  CI constraint loud)
- docs/connector-apache.md (~80 lines, 10 quirks)
- docs/connector-f5.md (~190 lines, 10 quirks; two-tier validation
  recipe for operator-supplied real-F5 vagrant box)

Each doc follows the same structure:
- Overview
- Vendor versions tested
- Per-quirk operator guidance (one section per
  TestVendorEdge_<vendor>_<edge>_E2E)
- Troubleshooting matrix
- V3-Pro deferrals
- Related docs cross-refs

Other connector docs (HAProxy, Traefik, Caddy, Envoy, Postfix,
Dovecot, SSH, WinCertStore, JavaKeystore) live in docs/connectors.md
+ are referenced from the matrix.

Phase 15 next: per-vendor CI matrix job in
.github/workflows/ci.yml.
2026-04-30 16:16:48 +00:00

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3.8 KiB
Markdown

# Kubernetes Secrets Connector — Operator Deep-Dive
> Per Phase 14 of the deploy-hardening II master bundle.
## Overview
The K8s connector (`internal/connector/target/k8ssecret/`) deploys
TLS certs into `kubernetes.io/tls` Secrets. Atomic at the API
server level (Update is transactional); the post-deploy verify
SHA-256-compares the returned Secret data against deployed bytes
(defends against admission webhooks that modify cert data).
## Vendor versions tested
- **Kubernetes 1.28 LTS**
- **Kubernetes 1.30**
- **Kubernetes 1.31** (current stable)
## Per-quirk operator guidance
### Kubelet sync wait contract
`TestVendorEdge_K8s_KubeletSyncWaitContract_DefaultTimeout60s_E2E`
After Secret update, kubelet projects new cert bytes into
pod-mounted volumes. Default sync interval ~60s. The connector
waits up to `CERTCTL_K8S_DEPLOY_KUBELET_SYNC_TIMEOUT` (default
60s).
**Operator action:** for slow clusters (large pod count, slow
node DNS), tune the env var upward. For fast clusters, the
default is fine.
### Admission webhook mutation
`TestVendorEdge_K8s_AdmissionWebhookModifiesSecretData_DeployDetectsViaSHA256Compare_E2E`
Some admission webhooks (Vault Agent Injector, OPA Gatekeeper)
mutate Secret data on Update. The connector pulls the Secret
back after Update and SHA-256-compares against deployed bytes.
Mismatch surfaces as deploy failure.
### Multi-version API stability
`TestVendorEdge_K8s_K8s128LTS_vs_130_vs_131_SecretAPIContractStable_E2E`
`kubernetes.io/tls` Secret schema (data.tls.crt + data.tls.key)
is stable across 1.28-1.31. No per-version branch needed.
### Typed vs Opaque Secret
`TestVendorEdge_K8s_TypedKubernetesIOTLSVsUntypedOpaque_DeployRespectsType_E2E`
Connector preserves operator-supplied Secret type. Typed
`kubernetes.io/tls` is the canonical form; untyped `Opaque` is
preserved for operators with legacy automation that expects it.
### Cert-manager interop
`TestVendorEdge_K8s_CertManagerInterop_RawSecretVsCertificateCRD_E2E`
Connector targets raw Secrets, NOT cert-manager `Certificate` CRs.
Operators using cert-manager should NOT also point certctl at the
same Secret name (cert-manager will overwrite). Documented
coexistence: certctl handles non-cert-manager Secrets;
cert-manager handles its own.
### Multi-namespace
`TestVendorEdge_K8s_MultiNamespaceDeploy_DeployUpdatesCorrectNamespace_E2E`
Connector targets the configured `Namespace` only. Cross-namespace
deploys require multiple connector entries.
### RBAC errors
`TestVendorEdge_K8s_RBACInsufficientPermissions_DeployFailsWithActionableError_E2E`
Connector surfaces the K8s API's `forbidden: secrets is restricted`
error verbatim. Operator action: bind a Role with
`secrets: get,update,create` verbs to the agent's ServiceAccount.
### Labels + annotations preservation
`TestVendorEdge_K8s_LabelsAnnotationsPreserved_E2E`
Connector merges (not replaces) operator-supplied metadata. Custom
labels/annotations on the Secret survive cert rotation.
### Pod-mounted Secret rollover
`TestVendorEdge_K8s_PodMountedSecretRollover_E2E`
When a pod mounts the Secret as a volume, kubelet projects new
cert bytes into the pod's filesystem after sync. Pods watching
the file (via inotify or polling) pick up the new cert without
restart.
### Immutable Secret flag
`TestVendorEdge_K8s_ImmutableSecretFlag_E2E`
K8s Secrets can be marked `immutable: true` for performance.
Update fails with actionable error; operator must drop the flag,
update, then re-apply if desired.
## V3-Pro deferrals
- cert-manager `Certificate` CR interop as first-class deploy
target (V3-Pro: certctl as cert-manager external issuer).
- Multi-cluster federation (deploy a single cert across N
clusters with single connector entry).
## Related docs
- [Atomic deploy + post-verify + rollback](deployment-atomicity.md)
- [Vendor compatibility matrix](deployment-vendor-matrix.md)