bake: infer git auth token from remote files to build request

[crazy-max]

When BUILDX_BAKE_GIT_AUTH_* env is set to fetch a remote bake definition, we should infer this git auth token to build request if a Git context is detected.

[tonistiigi]

This should be only if the context is git based I think. A remote bake definition may not always use the same remote URL as a context.

[crazy-max]

This should be only if the context is git based I think. A remote bake definition may not always use the same remote URL as a context.

I see but that could be unreliable if I use a remote bake def that has a target with subdir context like:

target "default" {
  context = "./subdir"
}

But I guess I can just check context does not start with cwd://

[tonistiigi]

bo would probably already have the context set correctly. If it is a subdir, then it would be a subdir of the git context in this case.

[crazy-max]

bo would probably already have the context set correctly. If it is a subdir, then it would be a subdir of the git context in this case.

Yes indeed, let me check this

[crazy-max]

@tonistiigi Should be good now

[tonistiigi]

I don't think this is correct. I think if you have a subpath in bake and command invoked directly then the contextpath in here is a subdir but the contextstate has been replaced with something like llb.Git().Copy("subdir")

[crazy-max]

Ah you right it would not work for this case

[tonistiigi]

isn't inp.URL always URL if it is set?

[crazy-max]

Yes if a remote bake def is set but if context is set to git context it is not (first cond in isRemoteContext):

docker buildx bake --set *.context=https://github.com/docker/buildx.git --print
{
  "group": {
    "default": {
      "targets": [
        "binaries"
      ]
    }
  },
  "target": {
    "binaries": {
      "context": "https://github.com/docker/buildx.git",
      "dockerfile": "Dockerfile",
      "args": {
        "BUILDKIT_CONTEXT_KEEP_GIT_DIR": "1"
      },
      "target": "binaries",
      "platforms": [
        "local"
      ],
      "output": [
        {
          "dest": "./bin/build",
          "type": "local"
        }
      ]
    }
  }
}

[tonistiigi]

Isn't that the build.IsRemoteURL(t.ContextPath) {, how does that affect inp.URL?

[crazy-max]

Isn't that the build.IsRemoteURL(t.ContextPath) {,

Yes it is but inp.URL is only set when remote bake def arg is set:

buildx/commands/bake.go

Line 557 in 026ac23

rfiles, inp, err = bake.ReadRemoteFiles(ctx, nodes, url, rnames, pw)

It doesn't take into account git urls in context within bake def or override.