How to Configure Credentials for a Proxy Repository to Google Container or Artifact Registry (GCR)

Defining a proxy repository that connects and authenticates against Google Container Registry or Artifact Registry is possible with Sonatype Nexus Repo 3.

To authenticate to these remote registries, Sonatype Nexus Repo requires using long lived service account credentials:

• Container Registry JSON Key
• Artifact Registry Service Account Key

How to Configure a Docker Proxy Repository to Container Registry or Artifact Registry

1. Configure the Remote URL to the recommended host names Google documents, without any trailing path information.
2. For authentication, go to the repo settings HTTP -> Authentication and set:
   
   1. Authentication Type: Username
   2. Username: _json_key
   3. Password: paste entire contents of json key file