Using a Certificate Issuer

Epinio comes with multiple cert-manager cluster issuers for creating certificates:

• epinio-ca (default)
• letsencrypt-production
• selfsigned-issuer

The issuer will be used for both, the Epinio API endpoint and workloads (i.e. pushed applications).

Choosing a Different Issuer

When installing Epinio with helm, you can choose between those issuers by using the global.tlsIssuer helm variable.

It's also possible to create a cert-manager cluster issuer in the cluster, before installing Epinio and referencing it by name when installing.

When using the letsencrypt-production issuer further use the global.tlsIssuerEmail helm variable to set an email address for the reception of the certificate notification emails sent by that issuer. Note, the default address is epinio@suse.com.

Cluster Issuer for ACME DNS Challenge

For example to use Letsencrypt with a DNS challenge, which supports wildcards and private IPs, create this cluster issuer after installing cert-manager:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: dns-staging
spec:
  acme:
    server: https://acme-staging-v02.api.letsencrypt.org/directory
    privateKeySecretRef:
      name: example-issuer-account-key
    solvers:
    - dns01:
        cloudflare:
          email: user@example.com
          apiKeySecretRef:
            name: cloudflare-apikey-secret
            key: apikey
      selector:
        dnsNames:
        - 'example.com'
        - '*.example.com'

Note: This uses the Letsencrypt staging endpoint for testing. More information in the cert-manager ACME docs.

You can then install Epinio with the global.tlsIssuer pointing to the new cluster issuer:

helm install epinio epinio/epinio --set global.tlsIssuer=dns-staging ...(other values here)

Cluster Issuer for Existing Private CA

According to the instructions from https://cert-manager.io/docs/configuration/ca/, follow these steps:

Create Secret With CA Cert and Key

If you don't already have a private CA, use a tool like openssl or easy-rsa to create it.

The following oneliner creates a CA:

openssl req -x509 -newkey rsa:4096 -sha256 -days 3650 -nodes \
  -keyout example.key -out example.crt -subj "/CN=*.yourdomainhere.org"

IMPORTANT: make sure the CN field matches the domain you are planning to use with Epinio

Create a Kubernetes secret from the CA, in the cert-manager namespace.

kubectl create secret -n cert-manager tls private-ca-secret \
  --cert=./example.crt --key=./example.key

The cert-manager documentation has more details about this.

Create ClusterIssuer

Then create the cluster issuer:

apiVersion: cert-manager.io/v1
kind: ClusterIssuer
metadata:
  name: private-ca
spec:
  ca:
    secretName: private-ca-secret

Install Epinio

Use the global.tlsIssuer variable to choose your cluster issuer:

helm install --set global.tlsIssuer=private-ca epinio epinio/epinio --global.domain=epinio.yourdomainhere.org

Background on Cert Manager and Issuers

Cert manager watches for a certificate resource and uses the referenced cluster issuer to generate a certificate. The certificate is stored in a secret, in the namespace the certificate resources was created in. An ingress resource can then use that secret to set up TLS.

Example:

1. The Epinio installation creates a certificate resource in epinio namespace

apiVersion: cert-manager.io/v1alpha2
kind: Certificate
metadata:
  name: epinio
  namespace: epinio
spec:
  commonName: epinio.172.27.0.2.omg.howdoi.website
  dnsNames:
  - epinio.172.27.0.2.omg.howdoi.website
  issuerRef:
    kind: ClusterIssuer
    name: epinio-ca
  secretName: epinio-tls

2. cert-manager creates the 'epinio-tls' secret, using the referenced cluster issuer 'epinio-ca'

apiVersion: v1
kind: Secret
type: kubernetes.io/tls
metadata:
  annotations:
    cert-manager.io/alt-names: epinio.172.27.0.2.omg.howdoi.website
    cert-manager.io/certificate-name: epinio
    cert-manager.io/common-name: epinio.172.27.0.2.omg.howdoi.website
    cert-manager.io/ip-sans: ""
    cert-manager.io/issuer-group: ""
    cert-manager.io/issuer-kind: ClusterIssuer
    cert-manager.io/issuer-name: epinio-ca
    cert-manager.io/uri-sans: ""
  name: epinio-tls
  namespace: epinio
data:
  ca.crt: ...
  tls.crt: ...
  tls.key: ...

3. Epinio creates an ingress resource

apiVersion: networking.k8s.io/v1
kind: Ingress
metadata:
  annotations:
    kubernetes.io/ingress.class: traefik
    traefik.ingress.kubernetes.io/router.entrypoints: websecure
    traefik.ingress.kubernetes.io/router.middlewares: epinio-epinio-api-auth@kubernetescrd
    traefik.ingress.kubernetes.io/router.tls: "true"
  labels:
    app.kubernetes.io/name: epinio
  name: epinio
  namespace: epinio
spec:
  rules:
  - host: epinio.172.27.0.2.omg.howdoi.website
    http:
      paths:
      - backend:
          service:
            name: epinio-server
            port:
              number: 80
        path: /
        pathType: ImplementationSpecific
  tls:
  - hosts:
    - epinio.172.27.0.2.omg.howdoi.website
    secretName: epinio-tls

Epinio Push

The same is true for applications, epinio push creates a certificate in the app's workspace and cert-manager creates a secret for the app's ingress.