feat(release): add script to publish to BCR (#15298)

* chore: POC of publishing googleapis to BCR via `git tag`

WIP

* fix: correct syntax for jq command

* feat(release): add script to publish to BCR

* docs(release): clarify BCR publishing process

* chore: restore unwanted changes

* chore: correct license header year

* chore: use same folder

* chore: fix quoting of `$@`

* docs: lint release readme

Author: diegomarquezp

release/README.md

@@ -10,13 +10,31 @@ project that need to create a new release. We expect the reader to be familiar
 the project itself, [git][git-docs], [GitHub][github-guides], and
 [semantic versioning](https://semver.org).
 
-## 0. Verify most recent googleapis SHA adheres to policy
+## 0. Update googleapis and Publish to BCR
 
-In order to ensure that our released version includes a SHA of the service proto
-definitions that is both current and stable ([googleapis-sha-update-policy]),
-aim for a commit SHA from 5-7 days ago (TODO(#13062): automate this update
-process). Specifying `COMMIT` and `COMMIT_DATE` when running `renovate.sh` can
-be used to achieve this.
+First, ensure that our release includes a `googleapis` commit that adheres to
+our [update policy][googleapis-sha-update-policy]. This generally means aiming
+for a commit that is 5-7 days old. You may need to run the `renovate.sh` script
+with a specific `COMMIT` and `COMMIT_DATE` to select the desired commit.
+
+Once the `googleapis` commit has been updated in our repository and the change
+is merged, run the `release/publish-bcr.sh` script using the same selected
+COMMIT. This script will create a Pull Request in the `googleapis/googleapis`
+repository to publish our new version to the Bazel Central Registry. You will
+need to provide the version number and the corresponding `googleapis` commit SHA
+to the script. Oversee the generated PR and ensure it is merged before
+proceeding with the release.
+
+```bash
+release/publish-bcr.sh --ref "${COMMIT}" --bcr_organization "${your_gh_id}"
+```
+
+Note that either `--bcr_organization` or `--bcr_folder` are necessary in order
+for the script to use your fork of `bazel-central-registry`. Pushes to the
+original `bazelbuild/bazel-central-registry` are not allowed.
+
+You can find more information about running the script in
+[its readme](https://github.com/googleapis/googleapis/blob/e1b12be90da62015f0bea9026d217f0abc32cafe/.bcr/README.md)
 
 ## 1. Preparing for a release
 

release/publish-bcr.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+#
+# Copyright 2025 Google LLC
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     https://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+set -euo pipefail
+
+tmpdir="/tmp/googleapis-publish-to-bcr"
+if [[ ! -d "${tmpdir}" ]]; then
+  git clone https://github.com/googleapis/googleapis "${tmpdir}"
+fi
+
+# Reset folder
+pushd "${tmpdir}"
+git reset --hard
+git clean -d -f
+git fetch --all
+git checkout master
+
+bash ".bcr/publish-to-bcr.sh" "${@}"