Recipes

Configuring Crane with pulp_docker

The Crane project can be used to make Docker repositories hosted by Pulp available to the Docker client. This allows a docker pull to be performed against data that is published by the Pulp server.

If Crane is being run on the same server that is running Pulp, there is one setting that must be configured in Crane in order for it to find the information that is published by Pulp. In the /etc/crane.conf the data_dir parameter must be set to a location that contains the app files that are generated during Pulp publish operations.

Pulp places these files in two locations, one for each version of Docker: /var/lib/pulp/published/docker/v1/app/ and /var/lib/pulp/published/docker/v2/app/. If you only plan to use one version of Docker content, you can set Crane’s data_dir setting to point at the appropriate path. If you plan to serve both, Crane can scan the whole /var/lib/pulp/published/docker path, filtering for *.json files. Crane will check the data_dir for updates periodically.

Full documentation for /etc/crane.conf can be found in the Crane README.

Sync

The pulp-docker plugin supports synchronizing from upstream repositories as of version 0.2.1. As of version 2.0.0, it can synchronize with either Docker v1 or v2 registries.

Note

registry-1.docker.io is a Docker V2 Registry API. For V1 API index.docker.io should be used, along with --enable-v1 true and --enable-v2 false. Please note however that V1 content is deprecated and Docker may remove it at any time.

$ pulp-admin docker repo create --repo-id=synctest --feed=https://registry-1.docker.io --upstream-name=busybox
Repository [synctest] successfully created

$ pulp-admin docker repo sync run --repo-id synctest
+----------------------------------------------------------------------+
                  Synchronizing Repository [synctest]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.


Downloading manifests
[\]
... completed

Copying units already in pulp
[-]
... completed

Copying units already in pulp
[-]
... completed

Downloading remote files
[==================================================] 100%
11 of 11 items
... completed

Saving Manifests and Blobs
[-]
... completed

Saving Tags
[-]
... completed


Task Succeeded




Task Succeeded

Once this is complete, the data in the remote repository is now in your local Pulp instance.

As mentioned, it is still possible to synchronize Docker v1 content if you use the old feed URL and enable/disable v1/v2:

$ pulp-admin docker repo create --repo-id=v1synctest --feed=https://index.docker.io --upstream-name=busybox --enable-v1 true --enable-v2 false
Repository [v1synctest] successfully created

$ pulp-admin docker repo sync run --repo-id v1synctest
+----------------------------------------------------------------------+
                 Synchronizing Repository [v1synctest]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.


Retrieving v1 metadata
[-]
... completed

Copying units already in pulp
[-]
... completed

Downloading remote files
[==================================================] 100%
53 of 53 items
... completed

Saving v1 images and tags
[-]
... completed


Task Succeeded




Task Succeeded

Publish

The repositories created above can be published for use with Crane.

First the Docker repository name must be specified, which can be different than the repo_id. The repository name should usually have a namespace, a /, and then a name. Other than the slash between the namespace and the name, it is required that this field can contain only lower case letters, integers, hyphens, and periods. The command below sets the repository name to pulpdemo/synctest:

$ pulp-admin docker repo update --repo-id=synctest --repo-registry-id=pulpdemo/synctest
This command may be exited via ctrl+c without affecting the request.


[\]
Running...
Updating distributor: docker_web_distributor_name_cli

Task Succeeded



[\]
Running...
Updating distributor: docker_export_distributor_name_cli

Task Succeeded

Then a publish operation can be executed:

$ pulp-admin docker repo publish run --repo-id=synctest
+----------------------------------------------------------------------+
                    Publishing Repository [synctest]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.



Task Succeeded

Crane can now be run on the same machine serving the Docker repository through its Docker-registry-like read-only API.

Upload v1 Images to Pulp

Note

As of the time of this writing, docker save can only output Docker v1 content. Thus, only Docker v1 content can be uploaded to Pulp for now. In order to get your own Docker v2 content into Pulp, it is possible to run your own Docker registry and point Pulp’s feed URL at it and synchronize.

To upload a Docker Image to Pulp, first you must save its repository with Docker. Note that the below command saves all of the Images and tags in the busybox repository to a tarball:

$ sudo docker pull busybox
$ sudo docker save busybox > busybox.tar

Then create a Pulp repository and run an upload command with pulp-admin:

$ pulp-admin docker repo create --repo-id=busybox
Repository [busybox] successfully created

$ pulp-admin docker repo uploads upload --repo-id=busybox -f busybox.tar
+----------------------------------------------------------------------+
                              Unit Upload
+----------------------------------------------------------------------+

Extracting necessary metadata for each request...
[==================================================] 100%
Analyzing: busybox.tar
... completed

Creating upload requests on the server...
[==================================================] 100%
Initializing: busybox.tar
... completed

Starting upload of selected units. If this process is stopped through ctrl+c,
the uploads will be paused and may be resumed later using the resume command or
canceled entirely using the cancel command.

Uploading: busybox.tar
[==================================================] 100%
2825216/2825216 bytes
... completed

Importing into the repository...
This command may be exited via ctrl+c without affecting the request.


[\]
Running...

Task Succeeded


Deleting the upload request...
... completed

There are now Images in the Pulp repository:

$ pulp-admin docker repo list
+----------------------------------------------------------------------+
                          Docker Repositories
+----------------------------------------------------------------------+

Id:                  busybox
Display Name:        busybox
Description:         None
Content Unit Counts:
  Docker Image: 4

Note

The number of Images associated with the repository at this point may differ from the number seen above, but should be at least 1 Image.

During an Image upload, you can specify the id of an ancestor Image that should not be uploaded to the repository. In this case, the masked ancestor and any ancestors of that Image will not be imported:

$ pulp-admin docker repo create --repo-id tutorial
Repository [tutorial] successfully created

$ pulp-admin docker repo uploads upload --repo-id tutorial
-f /home/skarmark/git/pulp1/pulp/tutorial.tar
--mask-id 'f38e479062c4953de709cc7f08fa8f85bec6bc5d01f03e340f7caf2990e8efd1'
+----------------------------------------------------------------------+
                          Unit Upload
+----------------------------------------------------------------------+

Extracting necessary metadata for each request...
[==================================================] 100%
Analyzing: tutorial.tar
... completed

Creating upload requests on the server...
[==================================================] 100%
Initializing: tutorial.tar
... completed

Starting upload of selected units. If this process is stopped through ctrl+c,
the uploads will be paused and may be resumed later using the resume command or
canceled entirely using the cancel command.

Uploading: tutorial.tar
[==================================================] 100%
353358336/353358336 bytes
... completed

Importing into the repository...
This command may be exited via ctrl+c without affecting the request.


[\]
Running...

Task Succeeded


Deleting the upload request...
... completed

There are now only two Images imported into the Pulp repository, instead of five total Images in the tar file:

$ pulp-admin docker repo list
+----------------------------------------------------------------------+
                        Docker Repositories
+----------------------------------------------------------------------+

Id:                  tutorial
Display Name:        tutorial
Description:         None
Content Unit Counts:
    Docker Image: 2

v1 Export

The busybox repository can also be exported for a case where Crane will be run on a different machine, or the Image files will be hosted by another service:

$ pulp-admin docker repo export run --repo-id=busybox
+----------------------------------------------------------------------+
                    Publishing Repository [busybox]
+----------------------------------------------------------------------+

This command may be exited via ctrl+c without affecting the request.


Publishing Image Files.
[==================================================] 100%
4 of 4 items
... completed

Saving tar file.
[-]
... completed


Task Succeeded

Note

The number of Images that get published when you try this may differ from the number seen above, but should be at least 1 Image.

This produces a tarball at /var/lib/pulp/published/docker/v1/export/repo/busybox.tar which contains both a JSON file for use with crane, and the static Image files to which crane will redirect requests. See the Crane documentation for how to use that tarball.