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cnabio / cnab-to-oci

Tool to convert CNAB bundle.json to OCI index
Apache License 2.0
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fallback to relocation map when image is not found #82

Closed eunomie closed 4 years ago

eunomie commented 5 years ago

When we are doing the fixup of a bundle, apply relocation map when necessary.

Previous behaviour:

The goal of this commit is to add one more condition, to copy/mount images that has been previously pushed from the local docker image store and so that can be resolved using the relocation map.

So the behaviour looks like:

The affected workflow is the following:

  1. create a bundle referencing local images. Like after a docker app build
    • the bundle contains images with, by example, Image: web
  2. push it to a registry
  3. pull it (by example on an other machine)
    • the bundle contains Image: web associated to an entry in the relocation map: web: registry/user/repo:tag@sha256...
  4. push it (to an other registry or not)
    • the image web is not resolved in the registry (but the corresponding image has already been pushed)
    • the image cannot be pushed from the local docker image store (the image doesn't exist there)
    • the entry from the relocation maps is resolvable and can be copy or mount

Implementation details:

The way fixupBaseImage works has been changed. Instead of having a bunch of if/else a list of fixups functions is provided. Those functions are run one after the other. If the function returns an error, then we "try" with the next one. If the function returns a flag indicated it's OK, it means the image has been resolved, directly or using relocation map or after a push. Conditions (like checking the relocation map or the pushImages flag) are checked inside functions.

The order is the following:

  1. try to push by digest if image value is not set
  2. try to resolve using the relocation map
  3. try to resolve from bundle
  4. try to push from local image store
silvin-lubecki commented 4 years ago

@radu-matei PTAL