Tag resolution

Knative Serving resolves image tags to a digest when you create a Revision. This helps to provide consistency for Deployments. For more information, see the documentation on Why we resolve tags in Knative.

Important

The Knative Serving controller must be configured to access the container registry to use this feature.

Custom certificates

If you are using a registry that has a self-signed certificate, you must configure the Knative Serving controller to trust that certificate.

Knative Serving accepts the SSL_CERT_FILE and SSL_CERT_DIR environment variables.

You can configure trusting certificates by mounting your certificates into the controller Deployment, and then setting the environment variable appropriately.

For example, if you are using a custom-certs secret that contains your CA certificates, the Deployment object is as follows:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: controller
  namespace: knative-serving
spec:
  template:
    spec:
      containers:
        - name: controller
          volumeMounts:
            - name: custom-certs
              mountPath: /path/to/custom/certs
          env:
            - name: SSL_CERT_DIR
              value: /path/to/custom/certs
      volumes:
        - name: custom-certs
          secret:
            secretName: custom-certs

Corporate proxy

If you are behind a corporate proxy, you must proxy the tag resolution requests between the controller and your registry.

Knative accepts the HTTP_PROXY and HTTPS_PROXY environment variables, so you can configure the controller Deployment as follows:

apiVersion: apps/v1
kind: Deployment
metadata:
  name: controller
  namespace: knative-serving
spec:
  template:
    spec:
      containers:
        - name: controller
          env:
            - name: HTTP_PROXY
              value: http://proxy.example.com
            - name: HTTPS_PROXY
              value: https://proxy.example.com