Container Registry implements a Docker protocol so that you can push and pullimages directly with Docker clients, including theDocker command-line tool.

Google Cloud services that typically integrate withContainer Registry, such as Cloud Build and Google Kubernetes Engine, areconfigured by withdefault permissions to accessrepositories in the same project and do not require a separate client.

If you want to interact with Container Registry without the Docker client,we recommend using thegcrane tool. The tool provides:

• Simple commands that work with Container Registry, Artifact Registry, and otherregistries.
• Useful commands for Container Registry and Artifact Registry tasks that do nothave an equivalent command in the Google Cloud CLI or the Docker command-linetool, such as listing untagged images or copying images across registry hosts.

If gcrane isn't an appropriate option, you can use the Docker Registry HTTP API.

• SeeAuthenticating using the Docker Registry API for informationabout authentication using the API.
• Refer to theDocker Registry HTTP API V2 documentation for details about the APi request format.

Authenticating using the Docker Registry HTTP API

If using Docker or thegcrane tool is not an option, you can use the DockerRegistry HTTP API.

First, grant the requiredpermissions to your user account. You can then usethe Google Cloud CLI to create an access token for requests.

The following example shows the command forlisting tags, usingmy-image as the image andmy-project as the Google Cloud project. Thisexample also uses thejq command to filter and format the output returned byrequests, but it's optional. Thejq tool is included in Cloud Shell.

curl\-H"Authorization: Bearer$(gcloudauthprint-access-token)"\"https://gcr.io/v2/my-project/my-image/tags/list"|jq".tags"