[bazel] Move google_cloud_sdk to MODULE.bazel

This just wraps the existing repository_rule into a module_extension and
fixes the resulting path.

Bug: b/458681039
Change-Id: I0f8d824f5dc2a551208b056551ea01562946068f
Reviewed-on: https://skia-review.googlesource.com/c/buildbot/+/1122262
Reviewed-by: Kaylee Lubick <[email protected]>
Auto-Submit: Eric Boren <[email protected]>
Commit-Queue: Kaylee Lubick <[email protected]>
Commit-Queue: Eric Boren <[email protected]>

Author: erock2112

MODULE.bazel

@@ -642,3 +642,11 @@ http_file(
     sha256 = "1206e8a79b41cb22524f73afa4f4ee648478f46ef6990d78e7cc953665a1db89",
     url = "https://github.com/bazelbuild/bazel-toolchains/releases/download/v5.1.2/rbe_configs_gen_linux_amd64",
 )
+
+####################################################################################################
+# Google Cloud SDK (needed for the Google Cloud Emulators).
+####################################################################################################
+
+google_cloud_sdk = use_extension("//bazel/external:google_cloud_sdk.bzl", "google_cloud_sdk")
+google_cloud_sdk.download(name = "google_cloud_sdk")
+use_repo(google_cloud_sdk, "google_cloud_sdk")

MODULE.bazel.lock

@@ -33,14 +33,6 @@ rbe_exec_properties(
     name = "exec_properties",
 )
 
-#############################################################
-# Google Cloud SDK (needed for the Google Cloud Emulators). #
-#############################################################
-
-load("//bazel/external:google_cloud_sdk.bzl", "google_cloud_sdk")
-
-google_cloud_sdk(name = "google_cloud_sdk")
-
 # #################################################################################
 # # Google Chrome and Fonts (needed for Karma and Puppeteer tests, respectively). #
 # #################################################################################

WORKSPACE

@@ -87,7 +87,7 @@ filegroup(
     )
     fail_if_nonzero_status(exec_result, "Failed to install Cloud Emulators.")
 
-google_cloud_sdk = repository_rule(
+_google_cloud_sdk = repository_rule(
     implementation = _google_cloud_sdk_impl,
     attrs = {
         "quiet": attr.bool(
@@ -102,3 +102,20 @@ This rule hermetically downloads the Google Cloud SDK, then installs the Cloud E
 at the same exact revision. Therefore, this rule cannot be considered to be fully hermetic.
 """,
 )
+
+_download = tag_class(attrs = {
+    "name": attr.string(mandatory = True),
+})
+
+def _gcloud_sdk_impl(ctx):
+    for module in ctx.modules:
+        for tag in module.tags.download:
+            _google_cloud_sdk(name = tag.name)
+
+google_cloud_sdk = module_extension(
+    doc = "Bzlmod extension used to download the Google Cloud SDK and emulators.",
+    implementation = _gcloud_sdk_impl,
+    tag_classes = {
+        "download": _download,
+    },
+)

bazel/external/google_cloud_sdk.bzl

@@ -18,7 +18,7 @@ func FindGcloud() (string, error) {
 		return exec.LookPath("gcloud")
 	}
 	if runtime.GOOS == "linux" {
-		return filepath.Join(bazel.RunfilesDir(), "external", "google_cloud_sdk", "google-cloud-sdk", "bin", "gcloud"), nil
+		return filepath.Join(bazel.RunfilesDir(), "external", "_main~google_cloud_sdk~google_cloud_sdk", "google-cloud-sdk", "bin", "gcloud"), nil
 	}
 	return "", skerr.Fmt("unsupported runtime.GOOS: %q", runtime.GOOS)
 }