Files
certctl/docs/acme-cert-manager-walkthrough.md
T
shankar0123 39f065dda4 docs(acme-server): operator-facing reference + threat model + cert-manager walkthrough (Phase 6/7)
Doc-only commit closing the ACME-server work series. After this commit,
an outside reviewer (procurement engineer / Venafi diligence engineer /
Infisical-comparison-shopper) can read the docs cold, understand the
ACME server's surface, follow the cert-manager walkthrough, and reach
a deployment decision without escalating to certctl maintainers.

What ships:
  - docs/acme-server.md final pass: Auth-mode decision tree (when to
    use trust_authenticated vs challenge), RFC 8555 + RFC 9773
    conformance statement (section-by-section table of implemented
    plus procurement-honest 'not implemented' rows for EAB / multi-
    level wildcards / RFC 8738 / cross-CA proxying), Troubleshooting
    (5 failure modes — badNonce / unknownAuthority / HTTP-01
    connection refused / DNS-01 NXDOMAIN / rejectedIdentifier with
    canonical fix for each), Version pinning + tested clients table
    (cert-manager 1.15.0, lego v4, kind v0.20+, Caddy 2.7.x, Traefik
    3.0+), FAQ (5 entries — why two auth modes, vs cert-manager-
    against-LE, can-I-use-from-outside-K8s, migration story, audit-
    log catalog), See-also cross-link block.
  - docs/acme-cert-manager-walkthrough.md: kind → cert-manager →
    certctl → Certificate flow, with YAML blocks byte-equal to
    deploy/test/acme-integration/{clusterissuer-trust-authenticated,
    certificate-test}.yaml to prevent doc/test drift.
  - docs/acme-caddy-walkthrough.md: Caddyfile acme_ca + tls.cas
    options (OS trust store + Caddy pki.ca block).
  - docs/acme-traefik-walkthrough.md: certificatesResolvers.<name>.acme
    .caServer + serversTransport.rootCAs configuration.
  - docs/acme-server-threat-model.md: Threat surface map + JWS forgery
    resistance (alg-confusion / HS256 substitution / replayed nonce /
    URL spoofing / multi-sig / kid-vs-jwk / kid round-trip mismatch),
    Nonce store integrity rationale, HTTP-01 SSRF defense-in-depth
    (pre-dial check + per-dial check + per-redirect check + body cap +
    bounded redirects), DNS-01 cache-poisoning posture (default Google
    Public DNS + operator-owns-private-resolver-posture), TLS-ALPN-01
    chain-not-validated rationale (RFC 8737 §3 explicit), Rate-limit
    tuning, Audit trail catalog, Out-of-scope threats list.
  - docs/connectors.md: TOC renumbered 3→4 etc. to make room for new
    top-level 'ACME Server (Built-in)' section between Issuer Connector
    and Target Connector — distinguishes the consumer-side ACME
    (existing) from the new server-side ACME via env-var-prefix
    call-out (CERTCTL_ACME_* vs CERTCTL_ACME_SERVER_*).

DoD verification:
  - All 5 docs files exist with the structure prescribed by the
    Phase 6 prompt.
  - Every CERTCTL_ACME_SERVER_* env var in docs/acme-server.md maps
    to an actual lookup in internal/config/config.go (verified by
    'grep -oE | sort -u | diff' returning empty).
  - Every YAML snippet in docs/acme-cert-manager-walkthrough.md is
    byte-equal to the corresponding file in deploy/test/acme-integration/
    (verified with 'diff' against awk-extracted YAML blocks).
  - docs/connectors.md has the cross-link subsection with all 4 new
    docs referenced.
  - cowork/CLAUDE.md Architecture Decisions has the new ACME-server
    bullet documenting per-profile URL family + per-profile
    acme_auth_mode + Phase 4-5-6 progression.
  - cowork/WORKSPACE-CHANGELOG.md has the ACME-Server-6 entry plus
    the ACME-Server rollup spanning Phases 1a-6.
  - cowork/infisical-deep-research-results.md Rank 1 marked SHIPPED.
  - 'gofmt -l .' clean (no Go changes); 'go vet ./...' clean.

Acquisition-readiness: every one of the 12 acquisition-grade criteria
from cowork/acme-server-endpoint-prompt.md is verified by the test
suite (Phases 1a-5) plus this doc walkthrough (Phase 6). The full
RFC 8555 + RFC 9773 surface is live; the operator can deploy
end-to-end by reading one walkthrough doc and one env-var table.

Engineering history: cowork/WORKSPACE-CHANGELOG.md 'ACME-Server-6 (docs)'
+ ACME-Server rollup of all 6 phases.
2026-05-03 19:58:15 +00:00

255 lines
9.9 KiB
Markdown

# cert-manager Integration Walkthrough
End-to-end recipe for issuing certs from a certctl-server deployment
through cert-manager 1.15+. Target audience: Kubernetes operator who
has never deployed certctl before and wants a working
`Certificate``Secret` flow on their cluster in under 30 minutes.
The Phase 5 integration test (`make acme-cert-manager-test`) automates
exactly the recipe below. The YAML snippets in this doc are byte-equal
to the files under `deploy/test/acme-integration/` — re-running the
test from a fresh clone produces the same results documented here.
## Prereqs
- A Kubernetes cluster (kind / k3d / EKS / GKE / AKS / on-prem). For
local trial, `kind v0.20+` works exactly the way the Phase 5 test
uses it. The kind config lives at
[`deploy/test/acme-integration/kind-config.yaml`](../deploy/test/acme-integration/kind-config.yaml).
- `kubectl` v1.27+, `helm` v3.13+.
- `cert-manager` v1.15.0 installed in the `cert-manager` namespace.
If absent, run:
```
bash deploy/test/acme-integration/cert-manager-install.sh
```
which is the same idempotent installer the integration test uses.
- A certctl Helm chart published to a registry your cluster can pull
from. The Phase 5 test uses an `image.tag=test` placeholder; production
deployments use the actual image tag for your release line.
## Step 1 — Deploy certctl-server
```
helm install certctl-test deploy/helm/certctl/ \
--set acmeServer.enabled=true \
--set acmeServer.defaultProfileId=prof-test \
--set image.tag=test
kubectl wait --for=condition=Available --timeout=3m deployment/certctl-test
```
`acmeServer.enabled=true` flips the `CERTCTL_ACME_SERVER_ENABLED`
env var which gates the ACME route registration.
`acmeServer.defaultProfileId` sets `CERTCTL_ACME_SERVER_DEFAULT_PROFILE_ID`
so the `/acme/*` shorthand path mirrors the per-profile path family.
## Step 2 — Create the certctl profile
The ACME server requires a `certificate_profiles` row to bind issuance
to. Create one via the certctl API or GUI; for the simplest case set
`acme_auth_mode='trust_authenticated'`:
```
curl -X POST https://certctl-test.default.svc.cluster.local:8443/api/profiles \
-H 'Content-Type: application/json' \
-H "Authorization: Bearer $CERTCTL_API_KEY" \
-d '{
"id": "prof-test",
"name": "ACME test profile",
"issuer_id": "iss-internal-ca",
"max_ttl_seconds": 7776000,
"acme_auth_mode": "trust_authenticated"
}'
```
Auth-mode tradeoffs are covered in
[`docs/acme-server.md` § Auth-mode decision tree](./acme-server.md#auth-mode-decision-tree).
For first-time deployments, `trust_authenticated` is the right default.
## Step 3 — Capture the certctl bootstrap CA
cert-manager validates the certctl-server's TLS chain before sending
any account / order / finalize JWS. With certctl's self-signed
bootstrap cert (the demo default at `deploy/test/certs/server.crt`),
cert-manager rejects the directory URL with
`x509: certificate signed by unknown authority` unless you feed the
bootstrap CA in.
```
cat deploy/test/certs/ca.crt | base64 -w0
```
Capture the output for Step 4. This is **the** single biggest first-
time-deploy footgun on the cert-manager integration path. The reference
recipe lives in
[`docs/acme-server.md` § TLS trust bootstrap](./acme-server.md#tls-trust-bootstrap-read-this-before-configuring-cert-manager).
## Step 4 — Apply the ClusterIssuer
```yaml
# Phase 5 — sample ClusterIssuer for the certctl trust_authenticated
# auth mode (RFC 8555 §6 + certctl auth_mode=trust_authenticated, where
# the JWS-authenticated ACME account is trusted to issue any identifier
# the profile policy permits — no per-identifier ownership challenges).
#
# Use this as the starting template for any internal-PKI rollout.
# Replace the caBundle placeholder with the base64-encoded PEM of the
# certctl-server's self-signed bootstrap root, then `kubectl apply`.
#
# Generate the caBundle via:
# cat deploy/test/certs/ca.crt | base64 -w0
# (See certctl/docs/acme-server.md "TLS trust bootstrap" section for the
# end-to-end walkthrough — this is the single biggest first-time-deploy
# footgun on cert-manager, captured as audit fix #9.)
apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
name: certctl-test-trust
spec:
acme:
email: test@example.com
# Replace 'certctl-test' with your release name + adjust the
# profile path segment. Default profile path:
# https://<service>.<namespace>.svc.cluster.local:8443/acme/profile/<profile-id>/directory
server: https://certctl-test.default.svc.cluster.local:8443/acme/profile/prof-test/directory
# caBundle: Audit fix #9. cert-manager validates the ACME server's
# TLS chain before submitting any account/order/finalize. With a
# self-signed bootstrap root, the ClusterIssuer MUST carry the root
# explicitly via this field.
caBundle: |
LS0tLS1CRUdJTiBDRVJUSUZJQ0FURS0tLS0tCi4uLgotLS0tLUVORCBDRVJUSUZJQ0FURS0tLS0tCg==
privateKeySecretRef:
name: certctl-test-trust-account-key
solvers:
# In trust_authenticated mode the solver is unused at the
# validation step but cert-manager still requires at least one
# solver in the spec. http01-via-ingress-nginx is the cheapest
# placeholder shape that round-trips correctly through cert-
# manager's validation webhooks.
- http01:
ingress:
class: nginx
```
This block is byte-equal to
[`deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml`](../deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml).
Replace the `caBundle` placeholder with the base64 string from Step 3.
The full reference YAML lives at
[`deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml`](../deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml).
```
kubectl apply -f deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml
kubectl wait --for=condition=Ready --timeout=2m clusterissuer/certctl-test-trust
```
The solver block is a placeholder under `trust_authenticated` mode —
cert-manager 1.15 still requires at least one solver in the spec, but
certctl auto-resolves authzs without a solver round-trip. The
http01-ingress-nginx shape validates against cert-manager's webhook
without needing an actual ingress controller deployed.
For `challenge` mode profiles, swap to
[`deploy/test/acme-integration/clusterissuer-challenge.yaml`](../deploy/test/acme-integration/clusterissuer-challenge.yaml)
— same shape, but the solver is now load-bearing and you need
ingress-nginx (or your chosen ingress class) actually deployed for
HTTP-01 to work.
## Step 5 — Apply the Certificate
```yaml
# Phase 5 — Certificate resource the integration test applies and
# waits for. The certctl-test-trust ClusterIssuer (trust_authenticated
# mode) issues the cert without any solver round-trip; the resulting
# Secret 'test-com-tls' is asserted to carry tls.crt + tls.key.
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
name: test-com
namespace: default
spec:
secretName: test-com-tls
commonName: test.example.com
dnsNames:
- test.example.com
- www.test.example.com
issuerRef:
name: certctl-test-trust
kind: ClusterIssuer
duration: 720h # 30d
renewBefore: 240h # 10d
```
This block is byte-equal to
[`deploy/test/acme-integration/certificate-test.yaml`](../deploy/test/acme-integration/certificate-test.yaml).
```
kubectl apply -f deploy/test/acme-integration/certificate-test.yaml
kubectl wait --for=condition=Ready --timeout=3m certificate/test-com
```
cert-manager creates an `Order`, the ACME flow runs against certctl,
and the resulting Secret is populated.
## Step 6 — Verify
```
kubectl get certificate test-com -o wide
# NAME READY SECRET ISSUER STATUS AGE
# test-com True test-com-tls certctl-test-trust Certificate is up to date and has not expired 42s
kubectl get secret test-com-tls -o yaml | yq '.data."tls.crt"' | base64 -d | openssl x509 -noout -subject -issuer -dates
# subject= CN=test.example.com
# issuer= CN=certctl test internal CA
# notBefore=... notAfter=...
```
Both the cert-manager `Certificate` resource and the underlying Secret
are populated. The actor on the certctl side is `acme:<account-id>`,
which you can correlate via the `audit_events` table:
```
psql -c "SELECT created_at, action, resource_type, resource_id
FROM audit_events
WHERE actor LIKE 'acme:%'
ORDER BY created_at DESC LIMIT 10;"
```
## Common failure modes
These are operator-side; full troubleshooting reference is in
[`docs/acme-server.md` § Troubleshooting](./acme-server.md#troubleshooting).
- `400 Bad Request: badNonce` → clock skew between certctl-server and
cert-manager, or a multi-replica certctl fleet without sticky
sessions.
- `x509: certificate signed by unknown authority` → missing or stale
`caBundle`. Re-run Step 3, paste the fresh value.
- `connection refused` from the HTTP-01 validator → ingress controller
not deployed, OR your network blocks port 80 inbound to the solver
Ingress.
- `Ready=False` with `rejectedIdentifier` → CSR has a SAN your profile
policy doesn't permit. Decode the `subproblems` array of the RFC
7807 problem doc.
## Cleanup
```
kubectl delete -f deploy/test/acme-integration/certificate-test.yaml
kubectl delete -f deploy/test/acme-integration/clusterissuer-trust-authenticated.yaml
helm uninstall certctl-test
# Optional: delete the certctl profile via API.
```
## See also
- [`docs/acme-server.md`](./acme-server.md) — canonical reference.
- [`docs/acme-server-threat-model.md`](./acme-server-threat-model.md) —
security posture.
- [`docs/acme-caddy-walkthrough.md`](./acme-caddy-walkthrough.md) —
Caddy-side recipe.
- [`docs/acme-traefik-walkthrough.md`](./acme-traefik-walkthrough.md) —
Traefik-side recipe.
- [`deploy/test/acme-integration/`](../deploy/test/acme-integration/) —
Phase 5 integration test (the same recipe, automated).