cleanup: rename version file, add filegroup, fix var names, make public

Author: rickeylev

python/private/local_runtime_repo.bzl

@@ -25,10 +25,18 @@ _OnFailure = enum(
     FAIL = "fail",
 )
 
-_TOOLCHAIN_IMPL_TEMPLATE = """\
+_BUILD_BAZEL_TEMPLATE = """\
 # Generated by python/private/local_runtime_repo.bzl
 
-load("@rules_python//python/private:local_runtime_repo_setup.bzl", "define_local_runtime_toolchain_impl")
+load(
+    "@rules_python//python/private:local_runtime_repo_setup.bzl",
+    "define_local_runtime_toolchain_impl",
+    "define_local_runtime_targets",
+)
+
+package(
+    default_visibility = ["//visibility:public"]
+)
 
 define_local_runtime_toolchain_impl(
     name = "local_runtime",
@@ -41,6 +49,8 @@ define_local_runtime_toolchain_impl(
     implementation_name = "{implementation_name}",
     os = "{os}",
 )
+
+define_local_runtime_targets()
 """
 
 RUNTIME_INFO_BZL_TEMPLATE = """
@@ -175,7 +185,7 @@ def _local_runtime_repo_impl(rctx):
     else:
         logger.warn("No external python libraries found.")
 
-    build_bazel = _TOOLCHAIN_IMPL_TEMPLATE.format(
+    build_bazel = _BUILD_BAZEL_TEMPLATE.format(
         major = info["major"],
         minor = info["minor"],
         micro = info["micro"],
@@ -201,7 +211,9 @@ def _local_runtime_repo_impl(rctx):
     ))
 
     # Text format for `python.toolchain.python_version_file`
-    rctx.file("version.txt", "{major}.{minor}".format(**info))
+    # The name `python-version` is used to match pyenv and uv naming that looks
+    # for a `.python-version` file.
+    rctx.file("python-version", "{major}.{minor}".format(**info))
 
 local_runtime_repo = repository_rule(
     implementation = _local_runtime_repo_impl,
@@ -282,7 +294,7 @@ How to handle errors when trying to automatically determine settings.
 )
 
 def _expand_incompatible_template():
-    return _TOOLCHAIN_IMPL_TEMPLATE.format(
+    return _BUILD_BAZEL_TEMPLATE.format(
         interpreter_path = "/incompatible",
         implementation_name = "incompatible",
         interface_library = "None",

python/private/local_runtime_repo_setup.bzl

@@ -14,6 +14,7 @@
 
 """Setup code called by the code generated by `local_runtime_repo`."""
 
+load("@bazel_skylib//:bzl_library.bzl", "bzl_library")
 load("@bazel_skylib//lib:selects.bzl", "selects")
 load("@rules_cc//cc:cc_import.bzl", "cc_import")
 load("@rules_cc//cc:cc_library.bzl", "cc_library")
@@ -168,6 +169,23 @@ def define_local_runtime_toolchain_impl(
         visibility = ["//visibility:public"],
     )
 
+def define_local_runtime_targets():
+    native.filegroup(
+        name = "python-version",
+        srcs = ["python-version"],
+    )
+    native.filegroup(
+        name = "runtime_info",
+        srcs = ["runtime_info.json"],
+    )
+    bzl_library(
+        name = "runtime_info_bzl",
+        srcs = ["runtime_info.bzl"],
+        deps = [
+            Label("//python/private:local_runtime_repo_setup.bzl"),
+        ],
+    )
+
 def create_info_struct(info):
     self = struct(
         _info = info,

tests/integration/local_toolchains/MODULE.bazel

@@ -99,7 +99,7 @@ register_toolchains("@local_toolchains//:all")
 
 python = use_extension("@rules_python//python/extensions:python.bzl", "python")
 python.defaults(
-    python_version_file = "@local_python3//:version.txt",
+    python_version_file = "@local_python3//:python-version",
 )
 
 # todo: loosen toolchain checking. These lines are only necessary to satisfy