registry-image-resource

Registry Image Resource

Supports checking, fetching, and pushing of images to Docker registries.

This resource is intended as a replacement for the Docker Image resource. Here are the key differences:

• This resource is implemented in pure Go and does not use the Docker daemon or CLI. This makes it safer (no need for privileged: true), more efficient, and less error-prone (now that we're using Go APIs and not parsing docker CLI output).

• This resource has stronger test coverage.

• This resource does not and will never support building - only registry image pushing/pulling. Building should instead be done with something like the concourse/builder task (or anything that can produce OCI image tarballs).

• A goal of this resource is to stay as focused and simple as possible. The Docker Image resource grew way too large and complicated. There are simply too many ways to build and publish Docker images. It will be easier to support many smaller resources + tasks rather than one huge interface.

Source Configuration

• repository: Required. The name of the repository, e.g. alpine.

• tag: Optional. Default latest. The name of the tag to monitor and publish to.

• username and password: Optional. A username and password to use when authenticating to the registry. Must be specified for private repos or when using put.

• debug: Optional. Default false. If set, progress bars will be disabled and debugging output will be printed instead.

Behavior

check: Discover new digests.

Reports the current digest that the registry has for the tag configured in source.

in: Fetch the image's rootfs and metadata.

Fetches an image at a digest.

Parameters

• format: Optional. Default rootfs. The format to fetch as.

Files created by the resource

The resource will produce the following files:

• ./digest: A file containing the image's digest, e.g. sha256:....

The remaining files depend on the configuration value for format:

rootfs

The rootfs format will fetch and unpack the image for use by Concourse task and resource type images.

This the default for the sake of brevity in pipelines and task configs.

In this format, the resource will produce the following files:

• ./rootfs/...: the unpacked rootfs produced by the image.
• ./metadata.json: the runtime information to propagate to Concourse.

oci

The oci format will fetch the image and write it to disk in OCI format. This is analogous to running docker save.

In this format, the resource will produce the following files:

• ./image.tar: the OCI image tarball, suitable for passing to docker load.

out: Push an image up to the registry under the given tags.

Uploads an image to the registry under the tag configured in source.

The currently encouraged way to build these images is by using the concourse/builder task.

Parameters

• image: Required. The path to the OCI image tarball to upload.