V8 Buildbot: Auto-tag recipe.

scripts/slave/recipes/v8/auto_tag.py

Index: scripts/slave/recipes/v8/auto_tag.py
diff --git a/scripts/slave/recipes/v8/auto_tag.py b/scripts/slave/recipes/v8/auto_tag.py
new file mode 100644
index 0000000000000000000000000000000000000000..3706f86b2924b899dac4e73b6330ca00d2a28fbb
--- /dev/null
+++ b/scripts/slave/recipes/v8/auto_tag.py
@@ -0,0 +1,113 @@
+# Copyright 2015 The Chromium Authors. All rights reserved.
+# Use of this source code is governed by a BSD-style license that can be
+# found in the LICENSE file.
+
+import re
+
+DEPS = [
+  'bot_update',
+  'gclient',
+  'git',
+  'path',
+  'properties',
+  'python',
+  'raw_io',
+  'step',
+  'v8',
+]
+
+REPO = 'https://chromium.googlesource.com/v8/v8'
+BRANCH_RE = re.compile(r'^\d+\.\d+$')
+
+
+def GetCommitForRef(api, repo, ref):
+  step_result = api.git(
+      'ls-remote', repo, ref,
+      name='git ls-remote %s' % ref.split('/')[-1],
+      cwd=api.path['checkout'],
+      stdout=api.raw_io.output(),
+  )
+  result = step_result.stdout.strip()
+  if result:
+    # Extract hash if available. Otherwise keep empty string.
+    result = result.split()[0]
+  step_result.presentation.logs['ref'] = [result]
+  return result
+
+
+def PushRef(api, repo, ref, hsh):
+  api.git(
+      'push', repo, '+%s:%s' % (hsh, ref),
+      cwd=api.path['checkout'],
+  )
+
+
+def LogStep(api, text):
+  api.step('log', ['echo', text])
+
+
+def RunSteps(api):
+  # Ensure a proper branch is specified.
+  branch = api.properties.get('branch')
+  if not branch or not BRANCH_RE.match(branch):
+    raise api.step.InfraFailure('A release branch must be specified.')
+  repo = api.properties.get('repo', REPO)
+
+  api.gclient.set_config('v8')
+  api.bot_update.ensure_checkout(
+      force=True, no_shallow=True, with_branch_heads=True)
+
+  branch_ref = 'refs/branch-heads/%s' % branch
+  lkgr_ref = 'refs/heads/%s-lkgr' % branch
+
+  # Get current lkgr ref and update to HEAD.
+  new_lkgr = GetCommitForRef(api, repo, branch_ref)
+  current_lkgr = GetCommitForRef(api, repo, lkgr_ref)
+  # If the lkgr_ref doesn't exist, it's an empty string. In this case the push
+  # ref command will create it.
+  if new_lkgr != current_lkgr:
+    PushRef(api, repo, lkgr_ref, new_lkgr)
+  else:
+    LogStep(api, 'There is no new lkgr.')
+
+
+def GenTests(api):
+  hsh_old = '74882b7a8e55268d1658f83efefa1c2585cee723'
+  hsh_new = 'c1a7fd0c98a80c52fcf6763850d2ee1c41cfe8d6'
+
+  def Test(name, current_lkgr, new_lkgr):
+    return (
+        api.test(name) +
+        api.properties.generic(mastername='client.v8.fyi',
+                               buildername='Auto-tag',
+                               branch='3.4') +
+        api.override_step_data(
+            'git ls-remote 3.4',
+            api.raw_io.stream_output(new_lkgr, stream='stdout'),
+        ) +
+        api.override_step_data(
+            'git ls-remote 3.4-lkgr',
+            api.raw_io.stream_output(current_lkgr, stream='stdout'),
+        )
+    )
+
+  yield Test(
+      'same_lkgr',
+      hsh_old + '\trefs/heads/3.4-lkgr',
+      hsh_old + '\trefs/branch-heads/3.4',
+  )
+  yield Test(
+      'update',
+      hsh_old + '\trefs/heads/3.4-lkgr',
+      hsh_new + '\trefs/branch-heads/3.4',
+  )
+  yield Test(
+      'missing',
+      '',
+      hsh_new + '\trefs/branch-heads/3.4',
+  )
+  yield (
+      api.test('missing_branch') +
+      api.properties.generic(mastername='client.v8.fyi',
+                             buildername='Auto-tag')
+  )