Docker push image to repository

Question

When using "to be continuous" Docker template, the Docker image is built and pushed to DOCKER_SNAPSHOT_IMAGE or DOCKER_RELEASE_IMAGE.

Why is there a step to publish image with skopeo, if that is already done in the built step ?

Answer 1

The reason why the Docker template uses 2 images is explained in the documentation.

Basically the Docker image is first built and published as the snapshot image (DOCKER_SNAPSHOT_IMAGE). This is done in the package-build stage.

Once the image has been validated (by deploying and/or testing it thoroughly), the same image is promoted as the release image. This doesn't involve rebuilding it, just pushing it as another Docker image (DOCKER_RELEASE_IMAGE). For this we use Skopeo. This is done in the publish stage, that necessarily comes after package-test, deploy and acceptance.