Ensure exporter progress logs are properly keyed

[jedevc]

Fixes an issue with bake's progress output, where multiple exporters of the same type might be invoked, resulting in the logs writing over each other within the same section. Additionally, this will be important in the context of #2760, where the progress logs per output need to be appropriately separated.

Sample bake file:

group "default" {
  targets = ["foo", "bar", "baz"]
}

target "foo" {
  target = "foo"
  tags = [
    "docker.io/x/y:foo"
  ]
  output = ["type=image,push=true,registry.insecure=true"]
}

target "bar" {
  target = "bar"
  tags = [
    "docker.io/x/y:bar"
  ]
  output = ["type=image,push=true,registry.insecure=true"]
}

target "baz" {
  target = "baz"
  tags = [
    "docker.io/x/y:baz"
  ]
  output = ["type=image,push=true,registry.insecure=true"]
}

Before:

...
 => [bar] exporting to image                                                                                                0.2s
 => => exporting layers                                                                                                     0.1s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => pushing layers                                                                                                       0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => pushing manifest for docker.io/x/y:baz@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s
 => => pushing manifest for docker.io/x/y:foo@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s
 => => pushing manifest for docker.io/x/y:bar@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s

After:

...
 => [bar] exporting to image                                                                                                0.1s
 => => exporting layers                                                                                                     0.0s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => pushing layers                                                                                                       0.0s
 => => pushing manifest for docker.io/x/y:bar@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s
 => [foo] exporting to image                                                                                                0.1s
 => => exporting layers                                                                                                     0.0s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => pushing layers                                                                                                       0.0s
 => => pushing manifest for docker.io/x/y:foo@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s
 => [baz] exporting to image                                                                                                0.1s
 => => exporting layers                                                                                                     0.0s
 => => exporting manifest sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa                           0.0s
 => => exporting config sha256:bbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbbb                             0.0s
 => => pushing layers                                                                                                       0.0s
 => => pushing manifest for docker.io/x/y:baz@sha256:aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaa       0.0s

[tonistiigi]

Now they are only unique based on image export of cache export. I don't understand how this is related to the bake problem in the initial comment.

[jedevc]

Woops, have split out the cache inline cache properly as well.

The cache exports need to be properly split out similarly, or we see the same kind of issue for inline cache:

 => [build2] preparing layers for inline cache                                                                               0.0s

vs

 => [build] preparing layers for inline cache                                                                                0.0s
 => [build2] preparing layers for inline cache                                                                               0.0s

and for the other cache types:

 => [build] exporting cache                                                                                                  0.0s
 => => preparing build cache for export                                                                                      0.0s
 => => writing layer sha256:405f018f9d1d0f351c196b841a7c7f226fb8ea448acd6339a9ed8741600275a2                                 0.0s
 => => writing layer sha256:43e589df01ad343faa6df8cead3077e6a243707b2bf6ccdbb4468c403f108bac                                 0.0s
 => => writing config sha256:e6a9dc809c4c1c9ed9e39a1922683daf6cae50efd74a4fa381d6336a27f23ded                                0.0s
 => => writing manifest sha256:cbee18d53f489c98bf8a88d4ff95ed9ebed3c489f80c70cf707aa2195de18057                              0.0s

vs

 => [build] exporting cache                                                                                                  0.0s
 => => preparing build cache for export                                                                                      0.0s
 => => writing layer sha256:405f018f9d1d0f351c196b841a7c7f226fb8ea448acd6339a9ed8741600275a2                                 0.0s
 => => writing layer sha256:43e589df01ad343faa6df8cead3077e6a243707b2bf6ccdbb4468c403f108bac                                 0.0s
 => => writing config sha256:e6a9dc809c4c1c9ed9e39a1922683daf6cae50efd74a4fa381d6336a27f23ded                                0.0s
 => => writing manifest sha256:cbee18d53f489c98bf8a88d4ff95ed9ebed3c489f80c70cf707aa2195de18057                              0.0s
 => [build2] exporting cache                                                                                                 0.0s
 => => preparing build cache for export                                                                                      0.0s
 => => writing layer sha256:405f018f9d1d0f351c196b841a7c7f226fb8ea448acd6339a9ed8741600275a2                                 0.0s
 => => writing layer sha256:43e589df01ad343faa6df8cead3077e6a243707b2bf6ccdbb4468c403f108bac                                 0.0s
 => => writing config sha256:e6a9dc809c4c1c9ed9e39a1922683daf6cae50efd74a4fa381d6336a27f23ded                                0.0s
 => => writing manifest sha256:cbee18d53f489c98bf8a88d4ff95ed9ebed3c489f80c70cf707aa2195de18057                              0.0s

Essentially, we need to force the logs here to be unique per session (previously they were derived exclusively from the exporter's .Name(), e.g. for containerimage this is "exporting to image"). Since bake then spins up a session per target, then all the logs will get separated out properly.