https://registry.gift1000.co.kr/v2/openjdk21/manifests/0.001": tls: failed to verify certificate: x509: certificate is valid for ingress.local, not registry.gift1000.co.kr

빠른 진단

# 인증서에 어떤 이름(SAN)이 들어있는지 확인
openssl s_client -showcerts -connect registry.gift1000.co.kr:443 </dev/null 2>/dev/null | openssl x509 -noout -subject -ext subjectAltName

# Ingress와 TLS Secret 확인
kubectl -n nginx get ingress
kubectl -n nginx describe ingress <레지스트리-ingress-이름>
kubectl -n nginx get cert,secret | grep registry
kubectl -n nginx describe certificate <cert-이름>

Ingress에 인증서 적용

# registry.yml
apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  name: registry
  namespace: nginx
  annotations:
    cert-manager.io/cluster-issuer: letsencrypt-staging # 성공하면 prod로 변경
spec:
  ingressClassName: nginx
  tls:
  - hosts:
    - registry.gift1000.co.kr
    secretName: registry-gift1000-co-kr-tls
  rules:
  - host: registry.gift1000.co.kr
    http:
      paths:
      - path: /
        pathType: Prefix
        backend:
          service:
            name: registry-svc
            port:
              number: 5000   # 레지스트리 서비스 포트(보통 5000)

# 적용
# 인증서까지 생성됨
kubectl apply -f registry.yml