Pulp Docker Roadmap¶

This is a living document that is moving towards a long term plan to develop Docker plugin for Pulp 3.0 and beyond.

With Pulp as a docker registry you can:

- Mirror container image repositories hosted on Docker-hub, Google Container Registry, Quay.io, etc
- Reduce disk use space by mirroring container image repositories using the "on demand" policy. An image is only downloaded once it has been requested by a client.
- Use local filesystem or an object storage store such as S3 to host all the container images.
- Curate container images by whitelisting what is mirrored from an external repository.
- Curate container images by creating repository versions with a specific set of images.
- Create versioned repositories that can be promoted or rolled back with a single operation.

Pulp also has:
- tasking system that can be used to perform a variety of specialized work such as analysis of content. e.g. integration with clair-scanner
- a large community of users
- a commuity of plugin developers

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MVP¶

Supported Content Types¶

• Image manifest schema2 and schema1
• {color: #458b74} Manifest list
• {color: #458b74} Blob
• {color: #458b74} Tag

Pulp Docker Plugin Use Cases¶

MVP¶

Sync¶

• As a user I can sync docker repo from docker registry

• {color: #458b74} assumes registry is compliant v2 api specs
• {color: #458b74} with token based auth
• {color: #458b74} with basic auth
• {color: #458b74} specify `feed` and `upstream_name`

• {color: #458b74} As a user I can sync a registry by whitelisting tags ( Filtered Sync)
• {color: #458b74} As a user i can lazily fetch docker repo by specifying the download policy
• {color: #458b74} As a user I can sync a private docker repo from docker registry
• {color: #458b74} As a user I can sync from a docker repo published by Pulp ( pulp2pulp3 and pulp3pulp3 sync)
• {color: #458b74} As a user, I can mirror the content of a remote repository with an additive behaviour, so content is never removed locally.
• As a user I can validate the size and the checksum of downloaded content against metadata ( #2625 #2624)

NOTE: dropping enable_v1, enable_v2, mask_id options

Publish¶

• {color: #458b74} As a user I can distribute docker content
• {color: #458b74} As a user, I can specify publish_directory( i.e base_path) from which the content will be served( provided by pulp_core)
• As a user, I can specify repo-registry-id that will be used in the docker registry
• As a user i can specify redirect-url which will lead to the location the content is stored
• As a user I can specify whether i want to convert docker image schema2 to schema1( aka schema convertor, for older clients support)
• As a user I cam pull from docker registry that has auth mechanish
  *token auth
  *basic auth

As a result the above section should enable clients to perform `docker/podman pull`

NOTE dropping protected option

Filtering¶

• {color: #458b74} As a user I can filter tags and images by digest, media_type, tag_name

Addition of the content to the repo with deps¶

• As a user I can add Manifest and all Blobs it references to the destination repo
• As a user I can add Manifest List and all Manifests and Blobs it references to the destination repo
• As a user I can add Tag and all its' associated content it references to the destination repo

Removal of the content from the repo with deps¶

• As a user I can remove Manifest and all Blobs it references from the repo
• As a user I can remove Manifest List and all Manifests and Blobs it references from the repo
• As a user I can remove Tag and all its' associated content it references from the repo

NOTE units that are referenced by other units are not removed, unless force flag is specified

Force removal of the content from the repo with deps¶

• As a user I can remove Manifest and all Blobs it references from the repo
• As a user I can remove Manifest List and all Manifests and Blobs it references from the repo
• As a user I can remove Tag and all its' associated content it references from the repo

Copy of the content form source repo to the dest repo with deps¶

• {color: #458b74} As a user I can copy by digest, media_type Manifest and all Blobs it references from the source repo to the destination repo
• {color: #458b74} As a user I can copy by digest , media_type Manifest List and all Manifests and Blobs it references from the source repo to the destination repo
• {color: #458b74} As a user I can copy Tag by name and all its' associated content it references from the source repo to the destination repo

Adding/removing Tag via pulp api¶

• As a user I can Tag an imagine in a repo
• As a user I can Untag an imagine in a repo
• As a user I can point existing Tag to a different image in a repo

Post-MVP 4.1+¶

Sync¶

• As a user, I can sync from a repository with Forein Layers and save them in pulp for disconnected env.
• As a user, I can exactly mirror the content of a remote repository( mirror on sync)

Export¶

• As a user I can distribute docker content using a remote server ( rsync exporter)

Docker push¶

• As a user, I can 'docker push' to a Pulp repository
• As a user I can 'docker tag' to a Pulp repository

Skopeo copy¶

• As a user I can use skopeo pulp transport to push images to Pulp container registry

Enable v2/catalog endpoint¶

Custom Live API (4.1+))¶

• some dedicated storage for the metadata files ( remove the need of in-memory database)
• enable docker push functionality or provide this as a separate plugin/package

What will be dropped in Pulp3¶

• v1 API support. In Pulp3 we'll have just v2 api registry and corresponding v2 content types
• v1/search. There is no v2/search so `docker search` for v2 content will not work. If upstream docker will add support for v2 docker content search by the time we deliver docker plugin for pulp3 we will reconsider and include the endpoint.
• content protection. In Pulp3 docker repos will not support entitlement cert protection. ( option `protected` is dropped)
• export content into a tar file. It was possible to do so for v1 content.
• Crane is not longer used as a registry API. Pulp 3's ability to serve custom live APIs has made it possible for Crane's feature set to be incorporated into the pulp_docker plugin