Add and update git_repository and http_archive rules

[jayconrod]

Gazelle should be able to add and update git_repository and http_archive rules (the overlay rules provided by Gazelle, not the native rules of the same name) in WORKSPACE using a command like the one below:

gazelle update-repos -kind=git_repository example.com/repo

This will generate build files and write them to third_party/com_example_repo. The build files can be hand-edited and checked in.

The build files can be fixed and updated by running the same command again (perhaps without needing the -kind flag).

[negz]

This would have helped me today. I set out to add https://github.com/golang/dep to my workspace via a go_repository rule. Unfortunately one of dep's testdata/ directories contains a recursive symlink cycle (golang/dep#1412). Normally I'd use a # gazelle:exclude comment to work around this, but no such option exists for go_repository (bazel-contrib/rules_go#882).

Having failed to use a go_repository I attempted to use an http_archive with an overlay, but descended into Lovecraftian madness while attempting to use a mix of gazelle and hand-hacking to generate all the BUILD files required by dep. In the end I gave up and simply checked all of dep into //third_party and let Gazelle generate BUILD files for me.

[jayconrod]

Sorry for the bad experience. I'm currently working on a major refactoring right now which will allow Gazelle to support multiple languages. I hope to get back to feature requests like this soon after.

[negz]

@jayconrod No need to apologise. :)

I think I'd misunderstood how straightforward what I wanted to do would be anyhow. I was under the impression I'd be able to happily bazel run //third_party/go/github.com/golang/dep/cmd/dep on the contents of my bazel-managed repo similar to how bazel run //:gazelle works (kind of like bazelbuild/buildtools#316). I see now that gazelle has a lot of magic in its wrapper shell script to make that work.

[Fleker]

I am currently facing the same issue as noted in #178, where I want to be able to easily export LICENSE files in various repositories but I run into the error

no such target '@com_github_spf13_cobra//:LICENSE.txt': target 'LICENSE.txt' not declared in package ''; however, a source file of this name exists.  (Perhaps add 'exports_files(["LICENSE.txt"])' to /BUILD?) defined by /usr/local/google/home/fleker/.cache/bazel/_bazel_fleker/be884af2cdb0395c1e568ec4bb82fdd6/external/com_github_spf13_cobra/BUILD.bazel and referenced by '//cmd/notices:licenses_go'

As the repository, https://github.com/spf13/cobra, is using standard Golang tools and not Bazel, I am using Gazelle to import it. I don't see a mechanism to actually add an exports_files line to the virtually created BUILD file for the dependency.

If there was a setting to do this automatically, it would go a long way. As for now, I'm somewhat stymied by this barrier and not sure how to implement the license notices short of copying files around.

[pjjw]

@Fleker did you ever figure a workaround for this issue?

[Fleker]

It looks like I just copied every open-source license into a YAML file and print that out.