How do I check the certificate status?

# kubectl -n default describe certificate example-com
...
Status:
  Acme:
    Authorizations:
      Account:  https://acme-v01.api.letsencrypt.org/acme/reg/22442061
      Domain:   example.com
      Uri:      https://acme-v01.api.letsencrypt.org/acme/challenge/qJA9MGCZnUnVjAgxhoxONvDnKAsPatRILJ4n0lJ7MMY/4062050823
      Account:  https://acme-v01.api.letsencrypt.org/acme/reg/22442061
      Domain:   admin.example.com
      Uri:      https://acme-v01.api.letsencrypt.org/acme/challenge/pW2tFKLBDTll2Gx8UBqmEl846x5W-YpBs8a4HqstJK8/4062050808
      Account:  https://acme-v01.api.letsencrypt.org/acme/reg/22442061
      Domain:   www.example.com
      Uri:      https://acme-v01.api.letsencrypt.org/acme/challenge/LaZJMM9_OKcTYbEThjT3oLtwgpkNfbHVdl8Dz-yypx8/4062050792
  Conditions:
    Last Transition Time:  2018-04-02T18:01:04Z
    Message:               Certificate issued successfully
    Reason:                CertIssueSuccess
    Status:                True
    Type:                  Ready
Events:
  Type     Reason                 Age                 From                     Message
  ----     ------                 ----                ----                     -------
  Normal   PrepareCertificate     1m                cert-manager-controller  Preparing certificate with issuer
  Normal   PresentChallenge       1m                cert-manager-controller  Presenting http-01 challenge for domain example.com
  Normal   PresentChallenge       1m                cert-manager-controller  Presenting http-01 challenge for domain www.example.com
  Normal   PresentChallenge       1m                cert-manager-controller  Presenting http-01 challenge for domain admin.example.com
  Normal   SelfCheck              1m                cert-manager-controller  Performing self-check for domain admin.example.com
  Normal   SelfCheck              1m                cert-manager-controller  Performing self-check for domain example.com
  Normal   SelfCheck              1m                cert-manager-controller  Performing self-check for domain www.example.com
  Normal   ObtainAuthorization    55s               cert-manager-controller  Obtained authorization for domain example.com
  Normal   ObtainAuthorization    54s               cert-manager-controller  Obtained authorization for domain admin.example.com
  Normal   ObtainAuthorization    53s               cert-manager-controller  Obtained authorization for domain www.example.com

How do I get a list of certificates?

# kubectl get certificate --all-namespaces
NAMESPACE          NAME                            AGE
default            example-com                     13m

What types of certificates are supported?

Currently, the module supports the following two ClusterIssuers:

  • letsencrypt
  • letsencrypt-staging

Does the legacy tls-acme annotation work?

Yes, it works! The dedicated component (cert-manager-ingress-shim) automatically creates Certificate resources based on these annotations (in the same namespaces as those of Ingress resources with annotations).

Caution! The Certificate for a particular annotation is linked to the existing Ingress resource. The additional records are put into the existing Ingress resource instead of creating a separate one. Thus, the process will fail if authentication or whitelist is set for the primary Ingress. In this case, you shouldn’t use the annotation; use the Certificate instead.

Caution! If you switched to the Certificate instead of annotation, then you need to delete the annotation-based Certificate. Otherwise, the same Secret will be updated for both Certificates (this may lead to exceeding the Let’s Encrypt limits).

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/tls-acme: "true"           # here is the annotation!
  name: example-com
  namespace: default
spec:
  ingressClassName: nginx
  rules:
  - host: example.com
    http:
      paths:
      - backend:
          service:
            name: site
            port:
              number: 80
        path: /
        pathType: ImplementationSpecific
  - host: www.example.com                    # the additional domain
    http:
      paths:
      - backend:
          service:
            name: site
            port:
              number: 80
        path: /
        pathType: ImplementationSpecific
  - host: admin.example.com                  # another additional domain
    http:
      paths:
      - backend:
          service:
            name: site
            port:
              number: 80
        path: /
        pathType: ImplementationSpecific
  tls:
  - hosts:
    - example.com
    - www.example.com                        # the additional domain
    - admin.example.com                      # another additional domain
    secretName: example-com-tls              # the name of the certificate & secret

The “CAA record does not match issuer” error

Suppose cert-manager gets the following error when trying to provide a certificate:

CAA record does not match issuer

In this case, you have to check the CAA (Certificate Authority Authorization) DNS record of the domain for which the certificate is intended. For Let’s Encrypt certificates, the domain must have the issue "letsencrypt.org" CAA record. You can read more about CAA here and here.

Vault integration

You can use this manual for configuring certificate issuance using Vault.

After configuring PKI and enabling Kubernetes authorization, you have to:

  • Create a service account and copy its secret reference:

    kubectl create serviceaccount issuer
    ISSUER_SECRET_REF=$(kubectl get serviceaccount issuer -o json | jq -r ".secrets[].name")
    
  • Create an Issuer:

    kubectl apply -f - <<EOF
    apiVersion: cert-manager.io/v1
    kind: Issuer
    metadata:
      name: vault-issuer
      namespace: default
    spec:
      vault:
        # HashiCorp instruction has mistype here
        server: http://vault.default.svc.cluster.local:8200 
        path: pki/sign/example-dot-com # configure in pki setup step
        auth:
          kubernetes:
            mountPath: /v1/auth/kubernetes
            role: issuer
            secretRef:
              name: $ISSUER_SECRET_REF
              key: token
    EOF
    
  • Create a Certificate resource, to get a TLS certificate, which is issued by Vault CA:

    kubectl apply -f - <<EOF
    apiVersion: cert-manager.io/v1
    kind: Certificate
    metadata:
      name: example-com
      namespace: default
    spec:
      secretName: example-com-tls
      issuerRef:
        name: vault-issuer
      # domains are set on PKI setup
      commonName: www.example.com 
      dnsNames:
      - www.example.com
    EOF
    

How to secure cert-manager credentials?

If you don’t want to store credentials in the deckhouse ConfigMap (security reasons, for example), feel free to create your own ClusterIssuer / Issuer. For example, you can create your own ClusterIssuer for a route53 service in this way:

  • Create a Secret with credentials:

    kubectl apply -f - <<EOF
    apiVersion: v1
    kind: Secret
    type: Opaque
    metadata:
      name: route53
      namespace: default
    data:
      secret-access-key: MY-AWS-ACCESS-KEY-TOKEN
    EOF
    
  • Create a simple ClusterIssuer with reference to that secret:

    kubectl apply -f - <<EOF
    apiVersion: cert-manager.io/v1
    kind: ClusterIssuer
    metadata:
      name: route53
      namespace: default
    spec:
      acme:
        server: https://acme-v02.api.letsencrypt.org/directory
        privateKeySecretRef:
          name: route53-tls-key
        solvers:
        - dns01:
            route53:
              region: us-east-1
              accessKeyID: MY-AWS-ACCESS-KEY-ID
              secretAccessKeySecretRef:
                name: route53
                key: secret-access-key
    EOF
    
  • Order certificates as usual, using created ClusterIssuer:

    kubectl apply -f - <<EOF
    apiVersion: cert-manager.io/v1
    kind: Certificate
    metadata:
      name: example-com
      namespace: default
    spec:
      secretName: example-com-tls
      issuerRef:
        name: route53
      commonName: www.example.com 
      dnsNames:
      - www.example.com
    EOF