TLS Certificates

Applications that publish HTTP endpoints can be protected by TLS certificates. In the future, Acorn will provide built-in mechanisms to automatically provide certificates for each endpoint. Today, adding a certificate must follow the manual approach.

Manually adding certificates

Acorn will automatically look for SANs in secrets of type kubernetes.io/tls for the exposed FQDN of the application in the Acorn namespace.

Assume you are deploying an app and plan to host on my-app.example.com

Add existing certificates using kubectl

Before launching the application pre-create a secret in the acorn namespace containing the certificate like so:

kubectl create secret tls my-app-tls-secret --cert=path/to/my-app-tls.cert --key=path/to/my-app-tls.key

Add with Cert-Manager

If you are already using Cert-Manager today, you can leverage it with Acorn right away. First you must create a certificate resource in the Acorn namespace:

kubectl apply -n acorn -f ./my-cert.yaml

# my-cert.yaml
apiVersion: cert-manager.io/v1
kind: Certificate
metadata:
  name: registry-studio-cert
spec:
  dnsNames:
  - my-app.example.com
  issuerRef:
    group: cert-manager.io
    kind: ClusterIssuer
    name: prod-issuer
  secretName: my-app-tls-secret

Cert-Manager will create a certificate for my-app.example.com and store it in a secret my-app-tls-secret.

Consume the secret

Once you have manually created the TLS secret using one of the methods above you can consume it in your application.

When you deploy the application Acorn, you can launch with the FQDN of your app.

acorn run -p my-app.example.com:web [MY_APP_IMAGE]

Acorn will automatically inspect each certificate in the Acorn namespace for one that can be used with my-app.example.com. If no TLS secret is found with that FQDN, it will be exposed on HTTP only.