As a user, I can download Foreign layers

[pulpbot]

Author: amacdona@redhat.com (amacdona@redhat.com)

Redmine Issue: 4400, https://pulp.plan.io/issues/4400

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A new field was added to skip foreign layers with this issue: https://pulp.plan.io/issues/4171

The new field `include_foreign_layers` defaults to False and is not included on the Serializer, so for now it will always skip.

This story will require

1. Add `include_foreign_layers` to the serializer
2. add logic to download the foreign layer, which will need to retrieve the layer with an absolute url instead of a relative url.

[pulpbot]

From: amacdona@redhat.com (amacdona@redhat.com)
Date: 2019-02-13T15:52:18Z

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There is some complexity for implementing this. If we sync foreign layers, we will have to modify the manifests so they will not be treated as foreign layers by the client. This has implications for signed layers because the digests will change.

Because of this, I am prioritizing this as LOW. If users need this, please add your use case here.

[pulpbot]

From: @ipanova (ipanova@redhat.com)
Date: 2019-02-13T16:51:41Z

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https://docs.docker.com/registry/deploying/#considerations-for-air-gapped-registries
https://github.com/moby/moby/pull/33151/files#diff-77a3b9683ea5b78ddbf146c0cbad74e1R33

there is a daemon option allow-nondistributable-artifacts, if it is set then during image pull, client will try to pull from the registry and in case of failure it will follow the url.

[ipanova]

Foreign layers, aka non-distributable layers, are deprecated with OCI 1.1 spec https://opencontainers.org/posts/blog/2023-07-07-summary-of-upcoming-changes-in-oci-image-and-distribution-specs-v-1-1/#closing-thoughts

[lubosmj]

@ipanova, should we close this issue?