chore: Github action to help with release freezes (#12731)

Author: dazuma

.github/workflows/release-freeze.yml

@@ -0,0 +1,23 @@
+name: Freeze releases
+on:
+  workflow_dispatch:
+
+jobs:
+  generate-updates:
+    if: ${{ github.repository == 'googleapis/elixir-google-api' }}
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_TOKEN: ${{ secrets.YOSHI_CODE_BOT_TOKEN }}
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+      - name: Install Ruby 3.3
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.3"
+      - name: Install tools
+        run: |
+          gem install --no-document toys
+      - name: execute
+        run: |
+          toys freeze-releases -v --fork --on

.github/workflows/release-unfreeze.yml

@@ -0,0 +1,23 @@
+name: Unfreeze releases
+on:
+  workflow_dispatch:
+
+jobs:
+  generate-updates:
+    if: ${{ github.repository == 'googleapis/elixir-google-api' }}
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_TOKEN: ${{ secrets.YOSHI_CODE_BOT_TOKEN }}
+    steps:
+      - name: Checkout repo
+        uses: actions/checkout@v4
+      - name: Install Ruby 3.3
+        uses: ruby/setup-ruby@v1
+        with:
+          ruby-version: "3.3"
+      - name: Install tools
+        run: |
+          gem install --no-document toys
+      - name: execute
+        run: |
+          toys freeze-releases -v --fork --off

.toys/freeze-releases.rb

@@ -0,0 +1,83 @@
+# Copyright 2024 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
+#
+#     http://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.
+
+require "uri"
+
+desc "Freeze or unfreeze releases."
+
+flag :git_remote, "--remote=NAME" do
+  desc "The name of the git remote to use as the pull request head. If omitted, does not open a pull request."
+end
+flag :enable_fork, "--fork" do
+  desc "The github user for whom to create/use a fork"
+end
+
+exactly_one desc: "Operations" do
+  flag :on, desc: "Turn on the release freeze"
+  flag :off, desc: "Turn off the release freeze"
+end
+
+include :exec, e: true
+include :terminal
+
+include "yoshi-pr-generator"
+
+def run
+  setup
+  result = pr_update_freeze
+  check_result result
+end
+
+def setup
+  yoshi_utils.git_ensure_identity
+  if enable_fork
+    set :git_remote, "pull-request-fork" unless git_remote
+    yoshi_utils.gh_ensure_fork remote: git_remote
+  end
+end
+
+def pr_update_freeze
+  timestamp = Time.now.utc.strftime("%Y%m%d-%H%M%S")
+  file_path = "#{context_directory}/.kokoro/release.sh"
+  branch_name = "pr/freeze-update-#{timestamp}"
+  commit_message = "chore: #{on ? 'Activate' : 'Deactivate'} release freeze"
+  yoshi_pr_generator.capture enabled: !git_remote.nil?,
+                             remote: git_remote,
+                             branch_name: branch_name,
+                             commit_message: commit_message do
+    content = File.read file_path
+    new_line = on ? "FREEZE_RELEASES=true" : "FREEZE_RELEASES="
+    new_content = content.gsub(/FREEZE_RELEASES=.*$/, new_line)
+    if content == new_content
+      puts "No changes for release freeze", :yellow, :bold
+      exit 1
+    end
+    File.write file_path, new_content
+  end
+end
+
+def check_result result
+  case result
+  when Integer
+    puts "Opened pull request #{result}", :green, :bold
+  when :unchanged
+    puts "No changes for release freeze", :yellow, :bold
+    exit 1
+  when :aborted
+    puts "Error when modifying scripts for release freeze", :red, :bold
+    exit 1
+  else
+    puts "Modified scripts for release freeze", :cyan
+  end
+end