Mirror images to another registry

Mirror images to another registry

Mirantis Secure Registry allows you to create mirroring policies for a repository. When an image gets pushed to a repository and meets the mirroring criteria, MSR automatically pushes it to a repository in a remote Mirantis Secure Registry or Hub registry.

This not only allows you to mirror images but also allows you to create image promotion pipelines that span multiple MSR deployments and datacenters.

In this example we will create an image mirroring policy such that:

  1. Developers iterate and push their builds to msr-example.com/dev/website the repository in the MSR deployment dedicated to development.

  2. When the team creates a stable build, they make sure their image is tagged with -stable.

  3. When a stable build is pushed to msr-example.com/dev/website, it will automatically be pushed to qa-example.com/qa/website, mirroring the image and promoting it to the next stage of development.

With this mirroring policy, the development team does not need access to the QA cluster, and the QA team does not need access to the development cluster.

You need to have permissions to push to the destination repository in order to set up the mirroring policy.

Configure your repository connection

Once you have created a repository, navigate to the repository page on the web interface, and select the Mirrors tab.

Click New mirror to define where the image will be pushed if it meets the mirroring criteria.

Under Mirror direction, choose Push to remote registry. Specify the following details:

Field

Description

Registry type

You can choose between Mirantis Secure Registry and Docker Hub. If you choose MSR, enter your MSR URL. Otherwise, Docker Hub defaults to https://index.docker.io

Username and password or access token

Your credentials in the remote repository you wish to push to. To use an access token instead of your password, see authentication token.

Repository

Enter the namespace and the repository_name after the /

Show advanced settings

Enter the TLS details for the remote repository or check Skip TLS verification. If the MSR remote repository is using self-signed TLS certificates or certificates signed by your own certificate authority, you also need to provide the public key certificate for that CA. You can retrieve the certificate by accessing https://<msr-domain>/ca. Remote certificate authority is optional for a remote repository in Docker Hub.

Note

Make sure the account you use for the integration has permissions to write to the remote repository.

Click Connect to test the integration.

In this example, the image gets pushed to the qa/example repository of a MSR deployment available at qa-example.com using a service account that was created just for mirroring images between repositories.

Next, set your push triggers. MSR allows you to set your mirroring policy based on the following image attributes:

Name

Description

Example

Tag name

Whether the tag name equals, starts with, ends with, contains, is one of, or is not one of your specified string values

Copy image to remote repository if Tag name ends in stable

Component

Whether the image has a given component and the component name equals, starts with, ends with, contains, is one of, or is not one of your specified string values

Copy image to remote repository if Component name starts with b

Vulnarabilities

Whether the image has vulnerabilities – critical, major, minor, or all – and your selected vulnerability filter is greater than or equals, greater than, equals, not equals, less than or equals, or less than your specified number

Copy image to remote repository if Critical vulnerabilities = 3

License

Whether the image uses an intellectual property license and is one of or not one of your specified words

Copy image to remote repository if License name = docker

You can choose to keep the image tag, or transform the tag into something more meaningful in the remote registry by using a tag template.

In this example, if an image in the dev/website repository is tagged with a word that ends in stable, MSR will automatically push that image to the MSR deployment available at qa-example.com. The image is pushed to the qa/example repository and is tagged with the timestamp of when the image was promoted.

Everything is set up! Once the development team pushes an image that complies with the policy, it automatically gets promoted to qa/example in the remote trusted registry at qa-example.com.

Metadata persistence

When an image is pushed to another registry using a mirroring policy, scanning and signing data is not persisted in the destination repository.

If you have scanning enabled for the destination repository, MSR is going to scan the image pushed. If you want the image to be signed, you need to do it manually.

Where to go next

Mirror images from another registry.