Android Rules Starlark Migration

[jin]

Tracking bug for the Starlark migration of android_* rules to https://github.com/bazelbuild/rules_android

cc @bazelbuild/android

Timeline

June 4, 2018

• Initial export of rules_android macros to https://github.com/bazelbuild/rules_android

Related issues:

• Move android tools out of Bazel binary Move android tools out of Bazel binary #4116

[aj-michael]

Why is moving android tools out of the binary a blocking issue?

[jin]

@aj-michael renamed it to "related". It doesn't block the rewrite, but will be good to also migrate our tools out to tools_android (which @ahumesky is making)

[jin]

/tag @bazelbuild/android

[jin]

It would be great to have an update on the progress of the rules, considering that it's been 6 months since rules_android was created. @10-10-11 / @ahumesky?

[jin]

The rules_android roadmap is live: https://github.com/bazelbuild/rules_android/blob/master/ROADMAP.md

[cgruber]

Given the impending Bazel 1.0 release, can we get some progress update here? There are a lot of us, and several substantial migrations (including ours at Square), hanging on this dropping, so it would be nice to get a picture of where we're at. (@jin @ahumesky etc).

[keith]

Just want to throw in a +1 that the Lyft migration is also waiting on these and the kotlin rules.

[artem-zinnatullin]

Posted PR that updates Android tutorial on the website to use rules_android: #9220

[steeve]

Hey folks,

During BazelCon 2019, it was said that the starlark Android rules where at feature parity with the Java, in-Bazel ones. It was also said they were already used inside Google and that open source was going to be soon-ish.

Would it be possible to have an official statement as to what the roadmap is?
Since the rules_android repository hasn't had a commit in almost a year.

This also means that legacy Android rules won't probably much development, and issues such as #11497 don't have any clear way on how to approach them.

Thanks you

[ahumesky]

Although we don't have a concrete timeline, this is being actively worked on this quarter and next. The soonest we can publish something that works in a minimal way is probably middle of Q1 2021.

[ahumesky]

Hi all,
We've pushed a few updates to a "pre-alpha" branch of the rules_android repo:
https://github.com/bazelbuild/rules_android/tree/pre-alpha

These updates contain a significant amount of the Starlark code for the Android toolchains, resource processing, and the android_library rule. It should be possible to build an Android app using the Starlark version of android_library, and the native (i.e. Java) version of android_binary (the Starlark version of android_binary is still just a simple wrapper around the native version). See the readme for requirements.

Some of the next steps are to publish the Starlark version of aar_import, and to enable rules_jvm_external to generate dependencies using that Starlark version. After that, there is still a fair bit of work to be done to finish and publish the Starlark version of android_binary. We might also publish some intermediate steps (e.g. an android_binary that delegates functionality to helper rules written in Starlark, all wrapped in an android_binary macro. then over time the helper functions do more and more and the native version goes away).

[ahumesky]

To update on the progress here, the 0.5.1 release of rules_android contains mostly Starlark rules, with notable exception android_sdk_repository, android_local_test, android_sdk, android_ndk_repository, and all Android providers still relying on native rules.

rules_android 0.6.0 will contain fully Starlark rules, and the progress of the 0.6.0 release is being tracked in bazelbuild/rules_android#278

The native Android rules have been removed from Bazel 8, and rules_android 0.6.0 will be compatible with Bazel 8 for migration.

[ahumesky]

rules_android 0.6.0 has been released: https://github.com/bazelbuild/rules_android/releases/tag/v0.6.0. rules_android 0.6.0 contains fully Starlark Android rules, including Starlark Android Providers and the native Android rules have been removed in Bazel 8.

While the Starlark rules are near 1:1 replacements for the native, some differences should be noted:

1. R8 is supported, proguard is no longer supported
2. Legacy Android flags (--fat_apk_cpu, --android_crosstool_top, --android_cpu) are no-ops and replaced with toolchains and platforms (--android_platforms)
3. android_ndk_repository is migrated to https://github.com/bazelbuild/rules_android_ndk
4. android_instrumentation_test is migrated to https://github.com/bazelbuild/rules_utp
5. Manifests are merged in dependency order rather than legacy alphabetical order