How to fix cert-manager failed issue in Kubernetes

KubernetesINTERMEDIATEHIGHUpdated Dec 6, 2025· 150 views

cert-manager certificate issuance fails due to ACME validation errors, invalid issuer configuration, or challenge failures. Fix by verifying issuer status, checking DNS/HTTP validation, and reviewing logs.

Quick fix

Fixes cert-manager failed issue

kubectl describe certificate <cert-name>
kubectl get certificate <cert-name> -o yaml
  1. Check Certificate resource status
  2. Verify Issuer/ClusterIssuer status
  3. Review CertificateRequest status
  4. Check ACME challenge status
kubernetes — error
kubectl describe certificate <cert-name>
kubectl get certificate <cert-name> -o yaml
cert-manager failed issue

What this error means

cert-manager is a Kubernetes operator that automates TLS certificate provisioning. When certificate issuance fails, the Certificate resource shows Ready: False status and the controller cannot obtain a certificate from the issuer (Let's Encrypt, private CA, etc.). This prevents Ingress/Services from using HTTPS.

Typical symptoms

  • Certificate shows Ready: False status indefinitely
  • Certificate last renewal timestamp stuck in past
  • Challenge resource shows failed condition
  • ACME order shows invalid or failed state
  • CertificateRequest resource shows failed status
  • Error message about validation failure or DNS timeout
  • TLS handshake failures on Ingress/Service
  • cert-manager controller logs show repeated retry warnings

Common causes

  1. ACME challenge validation fails (DNS-01, HTTP-01)
  2. Invalid email address in ACME account (e.g., @example.com)
  3. ClusterIssuer/Issuer not in Ready state
  4. Issuer API key or credentials expired or revoked
  5. DNS propagation delay causing DNS-01 validation timeout
  6. HTTP-01 validation endpoint not reachable from ACME servers
  7. Certificate domain already issued with different account
  8. Resource quota or namespace limits exceeded

How to fix "cert-manager failed issue"

1Check Certificate resource status

View detailed status of the failing certificate:

bash
kubectl describe certificate <cert-name>
kubectl get certificate <cert-name> -o yaml

Look for "Ready: False" and check conditions for specific error.

2Verify Issuer/ClusterIssuer status

Ensure the issuer is properly configured and ready:

bash
kubectl describe issuer <issuer-name>
kubectl describe clusterissuer <issuer-name>

If not Ready, check CA certificate validity or ACME account status.

3Review CertificateRequest status

Check if CertificateRequest shows where issuance failed:

bash
kubectl get certificaterequest
kubectl describe certificaterequest <req-name>

This shows detailed error from the issuer.

4Check ACME challenge status

For ACME issuers, examine challenge resources:

bash
kubectl get challenge
kubectl describe challenge <challenge-name>

Look for "DNS name does not point to Waiting validation server" or HTTP connection errors.

5Verify DNS records for DNS-01 validation

For DNS-01 challenges, verify DNS is correctly configured:

bash
nslookup _acme-challenge.example.com
dig _acme-challenge.example.com TXT

DNS record must exist before ACME server checks it.

6Test HTTP-01 validation endpoint

For HTTP-01 challenges, verify the validation endpoint is reachable:

bash
curl -v http://example.com/.well-known/acme-challenge/<token>

Must return the validation token, not redirect or 404.

7Fix invalid ACME account email

If issuer uses invalid email (@example.com), delete and recreate:

bash
kubectl delete secret letsencrypt-account -n cert-manager
kubectl delete issuer <issuer-name>
# Recreate issuer with valid email

Use real email addresses for production ACME accounts.

8Review cert-manager controller logs

Check controller logs for detailed error information:

bash
kubectl logs -n cert-manager deploy/cert-manager --tail=100
kubectl logs -n cert-manager deploy/cert-manager-webhook --tail=100

Look for specific validation or API errors.

Advanced notes

For production, use real email addresses for Let's Encrypt and monitor certificate expiration dates. Implement DNS validation (DNS-01) for wildcard certificates and internal domains. For high-volume issuance, implement certificate reuse to avoid ACME rate limits. Store ACME account credentials as secret backups. Monitor cert-manager metrics (renewal timing, failure count) for early problem detection. Use staging ACME endpoints for testing before going to production.

Frequently asked questions

What does "cert-manager failed issue" mean?
cert-manager is a Kubernetes operator that automates TLS certificate provisioning. ). This prevents Ingress/Services from using HTTPS.
How do I fix "cert-manager failed issue"?
cert-manager certificate issuance fails due to ACME validation errors, invalid issuer configuration, or challenge failures. Fix by verifying issuer status, checking DNS/HTTP validation, and reviewing logs.
What causes "cert-manager failed issue"?
ACME challenge validation fails (DNS-01, HTTP-01) Invalid email address in ACME account (e.g., @example.com) ClusterIssuer/Issuer not in Ready state
Is the "cert-manager failed issue" error serious?
Yes. This is a high-severity error that usually blocks work until it is fixed, but the steps above resolve it.

Official resources & further reading