compute: create chromeos-bot-v2 image

 - Ensure buildbot is started after reboot
 - Install sysstat package for system performance monitoring.
 - Increase the file descriptor limit
 - Modified the exception handling so that the cleanup (instance deletion)
   is run when error occurs during image creation.

BUG=chromium:438839
TEST=Ran the script to create an image and launched an instance

Change-Id: I7c6a1498599e9cf4a634b0bee30012e707a10a4b
Reviewed-on: https://chromium-review.googlesource.com/233250
Tested-by: Yu-Ju Hong <yjhong@chromium.org>
Reviewed-by: Don Garrett <dgarrett@chromium.org>
Reviewed-by: Yu-Ju Hong <yjhong@chromium.org>
Commit-Queue: Yu-Ju Hong <yjhong@chromium.org>

3 files changed, 28 insertions, 6 deletions

diff --git a/compute/compute_configs.py b/compute/compute_configs.py
index 7ab3321aa..8838c80f1 100644
--- a/compute/compute_configs.py
+++ b/compute/compute_configs.py
@@ -11,7 +11,7 @@ from chromite.cbuildbot import constants
 
 PROJECT = 'chromeos-bot'
 DEFAULT_BASE_IMAGE = 'ubuntu-14-04-server-v20141016'
-DEFAULT_IMAGE_NAME = 'chromeos-bot-v1'
+DEFAULT_IMAGE_NAME = 'chromeos-bot-v2'
 DEFAULT_ZONE = 'us-east1-a'
 DEFAULT_SCOPES = ('https://www.googleapis.com/auth/devstorage.full_control',
                   'https://www.googleapis.com/auth/gerritcodereview')
diff --git a/compute/cros_compute.py b/compute/cros_compute.py
index 8fd3b7673..3f9b2b881 100644
--- a/compute/cros_compute.py
+++ b/compute/cros_compute.py
@@ -69,9 +69,9 @@ def BotifyInstance(instance, project, zone):
   dest_path = bot_constants.BOT_CREDS_TMP_PATH
   src_path = os.getenv(bot_constants.BOT_CREDS_DIR_ENV_VAR)
   if not src_path:
-    cros_build_lib.Die('Environment variable %s is not set. This is necessary'
-                       'to set up credentials for the bot.'
-                       % bot_constants.BOT_CREDS_DIR_ENV_VAR)
+    raise ValueError('Environment variable %s is not set. This is necessary'
+                     'to set up credentials for the bot.'
+                     % bot_constants.BOT_CREDS_DIR_ENV_VAR)
   gcctx.CopyFilesToInstance(instance, src_path, dest_path)
   gcctx.SSH(
       instance,
@@ -169,10 +169,10 @@ def CreateImageForCrosBots(project, zone):
   gcctx.CreateInstance(instance, image=compute_configs.DEFAULT_BASE_IMAGE)
   try:
     BotifyInstance(instance, project, zone)
-    # TODO: remove unncessary files.
-  except Exception:
+  except:
     # Clean up the temp instance.
     gcctx.DeleteInstance(instance)
+    raise
 
   gcctx.DeleteInstance(instance, keep_disks='boot')
   # By default the name of the boot disk is the same as the name of
diff --git a/compute/setup_bot.py b/compute/setup_bot.py
index d26d35738..8c6c11336 100644
--- a/compute/setup_bot.py
+++ b/compute/setup_bot.py
@@ -35,6 +35,10 @@ def SetupPrerequisites():
   packages += ['python-sqlalchemy', 'python-mysqldb']
   # Required for payload generation outside of the chroot.
   packages += ['python-protobuf']
+
+  # Packages to monitor system performance and usage.
+  packages += ['sysstat']
+
   SudoRunCommand(['apt-get', '-y', 'install'] + packages)
 
 
@@ -175,6 +179,23 @@ def SetupBuildbotEnvironment():
   RunCommand(['bash', '-c', r'echo export PATH=\$PATH:%s >> ~/.bashrc'
               % depot_tools_path])
 
+  # Start buildbot slave at startup.
+  crontab_content = ''
+  result = RunCommand(
+      ['crontab', '-l'], capture_output=True, error_code_ok=True)
+  crontab_content = result.output if result.returncode == 0 else ''
+  crontab_content += ('SHELL=/bin/bash\nUSER=chrome-bot\n'
+                      '@reboot cd /b/build/slave && make start\n')
+  RunCommand(['crontab', '-'], input=crontab_content)
+
+
+def TuneSystemSettings():
+  """Tune the system settings for our build environment."""
+  # Increase the user-level file descriptor limits.
+  entries = ('*       soft    nofile  65536\n'
+             '*       hard    nofile  65536\n')
+  SudoRunCommand(['tee', '-a', '/etc/security/limits.conf'], input=entries)
+
 
 def main(_argv):
   assert getpass.getuser() == bot_constants.BUILDBOT_USER, (
@@ -184,3 +205,4 @@ def main(_argv):
   InstallChromeDependencies()
   SetupCredentials()
   SetupBuildbotEnvironment()
+  TuneSystemSettings()