chore: enable bzlmod by default (for Bazel 6) (#1632)

This enables bzlmod by default so that, by default, builds are using it
for both Bazel 6
and Bazel 7.

This exposed some gaps in our test coverage, so some new jobs are
created to cover
minimum bzlmod and workspace versions. Basically, our CI config used
mostly
workspace builds, while Bazel's downstream testing used bzlmod builds.
Changing
our config to default to bzlmod means we lost most workspace build
coverage.

Unfortunately, adding these new jobs goes over the CI job limit, so I
consolidated
tests a bit:
* The py_proto_library example for bzlmod is moved under the bzlmod
example. This saves
  about 6 jobs
* Change some tests with both (Bazel 7, workspace) and (Bazel 6,
workspace) to have
just one of the two. This saves about 4 jobs. Many jobs still test both,
so coverage
  should still be sufficient.

Also some various cleanups:
* Deletes the last bazel-in-bazel integration test using our old,
private, fork of
bazel_integration_test. It hasn't been running in a long time and is
broken.
* Renames the CI jobs to have shorter names.

.bazelrc

@@ -3,8 +3,8 @@
 # This lets us glob() up all the files inside the examples to make them inputs to tests
 # (Note, we cannot use `common --deleted_packages` because the bazel version command doesn't support it)
 # To update these lines, run tools/bazel_integration_test/update_deleted_packages.sh
-build --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/dupe_requirements,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,tests/compile_pip_requirements,tests/compile_pip_requirements_test_from_external_workspace,tests/ignore_root_user_error,tests/pip_repository_entry_points
-query --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/dupe_requirements,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,tests/compile_pip_requirements,tests/compile_pip_requirements_test_from_external_workspace,tests/ignore_root_user_error,tests/pip_repository_entry_points
+build --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/dupe_requirements,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/ignore_root_user_error,tests/integration/pip_repository_entry_points
+query --deleted_packages=examples/build_file_generation,examples/build_file_generation/random_number_generator,examples/bzlmod,examples/bzlmod_build_file_generation,examples/bzlmod_build_file_generation/other_module/other_module/pkg,examples/bzlmod_build_file_generation/runfiles,examples/bzlmod/entry_points,examples/bzlmod/entry_points/tests,examples/bzlmod/libs/my_lib,examples/bzlmod/other_module,examples/bzlmod/other_module/other_module/pkg,examples/bzlmod/patches,examples/bzlmod/py_proto_library,examples/bzlmod/py_proto_library/example.com/another_proto,examples/bzlmod/py_proto_library/example.com/proto,examples/bzlmod/runfiles,examples/bzlmod/tests,examples/bzlmod/tests/dupe_requirements,examples/bzlmod/tests/other_module,examples/bzlmod/whl_mods,examples/multi_python_versions/libs/my_lib,examples/multi_python_versions/requirements,examples/multi_python_versions/tests,examples/pip_parse,examples/pip_parse_vendored,examples/pip_repository_annotations,examples/py_proto_library,examples/py_proto_library/example.com/another_proto,examples/py_proto_library/example.com/proto,tests/integration/compile_pip_requirements,tests/integration/compile_pip_requirements_test_from_external_repo,tests/integration/ignore_root_user_error,tests/integration/pip_repository_entry_points
 
 test --test_output=errors
 
@@ -20,9 +20,8 @@ build --incompatible_default_to_explicit_init_py
 build --enable_runfiles
 startup --windows_enable_symlinks
 
-# TODO: migrate all dependencies from WORKSPACE to MODULE.bazel
-# https://github.com/bazelbuild/rules_python/issues/1469
-common --noexperimental_enable_bzlmod
+# Make Bazel 6 use bzlmod by default
+common --enable_bzlmod
 
 # Additional config to use for readthedocs builds.
 # See .readthedocs.yml for additional flags that can only be determined from

docs/sphinx/BUILD.bazel

@@ -89,9 +89,9 @@ sphinx_stardocs(
         # Bazel 6 + Stardoc isn't able to parse something about the python bzlmod extension
         "api/extensions/python.md": "//python/extensions:python_bzl",
     } if IS_BAZEL_7_OR_HIGHER else {}) | ({
-        # This depends on @pythons_hub, which is only created under bzlmod
+        # This depends on @pythons_hub, which is only created under bzlmod,
         "api/extensions/pip.md": "//python/extensions:pip_bzl",
-    } if BZLMOD_ENABLED else {}),
+    } if IS_BAZEL_7_OR_HIGHER and BZLMOD_ENABLED else {}),
     footer = "_stardoc_footer.md",
     tags = ["docs"],
     target_compatible_with = _TARGET_COMPATIBLE_WITH,

examples/bzlmod/MODULE.bazel

@@ -11,6 +11,12 @@ local_path_override(
     path = "../..",
 )
 
+# (py_proto_library specific) We are using rules_proto to define rules_proto targets to be consumed by py_proto_library.
+bazel_dep(name = "rules_proto", version = "5.3.0-21.7")
+
+# (py_proto_library specific) Add the protobuf library for well-known types (e.g. `Any`, `Timestamp`, etc)
+bazel_dep(name = "protobuf", version = "21.7", repo_name = "com_google_protobuf")
+
 # We next initialize the python toolchain using the extension.
 # You can set different Python versions in this block.
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")