Skip to content

SSL/TLS Certificates

KanjiIQ uses cert-manager with Let's Encrypt for automatic TLS certificate provisioning and renewal.

How It Works

sequenceDiagram
    participant I as Ingress Resource
    participant CM as cert-manager
    participant LE as Let's Encrypt
    participant T as Traefik
    participant S as K8s Secret

    I->>CM: New Ingress with cert-manager annotation
    CM->>LE: Request certificate (ACME HTTP-01)
    LE->>T: HTTP-01 challenge request
    T->>LE: Challenge response
    LE->>CM: Certificate issued
    CM->>S: Store as TLS Secret
    T->>S: Read certificate
    Note over T: HTTPS now active
    CM->>CM: Monitor expiry (auto-renew at 30 days)

ClusterIssuer

A cluster-wide issuer is configured for Let's Encrypt production:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: letsencrypt-prod
spec:
  acme:
    server: https://acme-v02.api.letsencrypt.org/directory
    email: [email protected]
    privateKeySecretRef:
      name: letsencrypt-prod
    solvers:
      - http01:
          ingress:
            class: traefik

Requesting Certificates

Any Ingress resource can request a TLS certificate by adding a single annotation:

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-prod
spec:
  tls:
    - hosts:
        - kanjiiq.com
        - api.kanjiiq.com
      secretName: kanjiiq-tls  # cert-manager creates this

cert-manager watches for Ingress resources with its annotation and automatically:

  1. Creates a Certificate resource
  2. Performs the ACME HTTP-01 challenge via Traefik
  3. Stores the issued certificate in the specified Secret
  4. Renews 30 days before expiry

Current Certificates

Secret Name Domains Ingress
kanjiiq-tls kanjiiq.com, www.kanjiiq.com, api.kanjiiq.com, admin.kanjiiq.com ingress-kanjiiq.yaml
kanjiiq-docs-tls docs.kanjiiq.app ingress-docs.yaml

Troubleshooting

Check certificate status:

# List all certificates
kubectl get certificates -n jlpt-kanji

# Check certificate details
kubectl describe certificate kanjiiq-tls -n jlpt-kanji

# Check cert-manager logs
kubectl logs -n cert-manager deploy/cert-manager

# View certificate challenges in progress
kubectl get challenges -n jlpt-kanji

Common issues:

  • Challenge fails: Ensure DNS A records point to the server and port 80 is accessible
  • Rate limited: Let's Encrypt has a 50 certificates/week limit per domain
  • Secret not created: Check cert-manager logs for ACME errors