scheduler: Rework entry points

As part of the effort to make autotest more packaging
friendly, refactor some of the scheduler code and
rename:

scheduler/monitor_db.py -> scheduler/autotest-scheduler
scheduler/monitor_db_babysitter.py -> scheduler/autotest-scheduler-watcher

This renaming makes the entry points easier to discover
and figure out what they do. The actual functionality
of the entry points was actually split to libraries,
to ease unit testing.

Signed-off-by: Lucas Meneghel Rodrigues <[email protected]>
Signed-off-by: Martin Krizek <[email protected]>

scheduler/autotest-scheduler

@@ -0,0 +1,13 @@
+#!/usr/bin/python -u
+"""
+Autotest scheduler.
+"""
+try:
+    import autotest.common as common
+except ImportError:
+    import common
+
+from autotest_lib.scheduler import monitor_db
+
+if __name__ == '__main__':
+    monitor_db.main()

scheduler/autotest-scheduler-watcher

@@ -0,0 +1,13 @@
+#!/usr/bin/python -u
+"""
+Autotest scheduler watcher.
+"""
+try:
+    import autotest.common
+except ImportError:
+    import common
+
+from autotest_lib.scheduler import monitor_db_watcher
+
+if __name__ == '__main__':
+    monitor_db_watcher.main()

scheduler/monitor_db.py

@@ -1,19 +1,12 @@
-#!/usr/bin/python -u
-
 """
-Autotest scheduler
+Autotest scheduler main library.
 """
-
-
 try:
     import autotest.common as common
 except ImportError:
     import common
-import datetime, errno, optparse, os, pwd, Queue, re, shutil, signal
-import smtplib, socket, stat, subprocess, sys, tempfile, time, traceback, urllib
-import itertools, logging, weakref, gc
-
-import MySQLdb
+import datetime, optparse, os, signal, sys, time, traceback, urllib
+import logging, gc
 
 from autotest_lib.scheduler import scheduler_logging_config
 from autotest_lib.frontend import setup_django_environment
@@ -29,8 +22,9 @@
 from autotest_lib.scheduler import gc_stats, host_scheduler, monitor_db_cleanup
 from autotest_lib.scheduler import status_server, scheduler_config
 from autotest_lib.scheduler import scheduler_models
-BABYSITTER_PID_FILE_PREFIX = 'monitor_db_babysitter'
-PID_FILE_PREFIX = 'monitor_db'
+
+WATCHER_PID_FILE_PREFIX = 'autotest-scheduler-watcher'
+PID_FILE_PREFIX = 'autotest-scheduler'
 
 RESULTS_DIR = '.'
 AUTOSERV_NICE_LEVEL = 10
@@ -58,6 +52,7 @@
 _testing_mode = False
 _drone_manager = None
 
+
 def _parser_path_default(install_dir):
     return os.path.join(install_dir, 'tko', 'parse')
 _parser_path_func = utils.import_site_function(
@@ -73,6 +68,32 @@ def _get_pidfile_timeout_secs():
     return pidfile_timeout_mins * 60
 
 
+def _autoserv_command_line(machines, extra_args, job=None,
+                           queue_entry=None, verbose=True):
+    """
+    @returns The autoserv command line as a list of executable + parameters.
+
+    @param machines - string - A machine or comma separated list of machines
+            for the (-m) flag.
+    @param extra_args - list - Additional arguments to pass to autoserv.
+    @param job - Job object - If supplied, -u owner and -l name parameters
+            will be added.
+    @param queue_entry - A HostQueueEntry object - If supplied and no Job
+            object was supplied, this will be used to lookup the Job object.
+    """
+    autoserv_argv = [_autoserv_path, '-p',
+                     '-r', drone_manager.WORKING_DIRECTORY]
+    if machines:
+        autoserv_argv += ['-m', machines]
+    if job or queue_entry:
+        if not job:
+            job = queue_entry.job
+        autoserv_argv += ['-u', job.owner, '-l', job.name]
+    if verbose:
+        autoserv_argv.append('--verbose')
+    return autoserv_argv + extra_args
+
+
 def _site_init_monitor_db_dummy():
     return {}
 
@@ -89,17 +110,62 @@ def _sanity_check():
     _verify_default_drone_set_exists()
 
 
-def main():
-    try:
-        try:
-            main_without_exception_handling()
-        except SystemExit:
-            raise
-        except:
-            logging.exception('Exception escaping in monitor_db')
-            raise
-    finally:
-        utils.delete_pid_file_if_exists(PID_FILE_PREFIX)
+def setup_logging():
+    log_dir = os.environ.get('AUTOTEST_SCHEDULER_LOG_DIR', None)
+    log_name = os.environ.get('AUTOTEST_SCHEDULER_LOG_NAME', None)
+    logging_manager.configure_logging(
+            scheduler_logging_config.SchedulerLoggingConfig(), log_dir=log_dir,
+            logfile_name=log_name)
+
+
+def handle_sigint(signum, frame):
+    global _shutdown
+    _shutdown = True
+    logging.info("Shutdown request received.")
+
+
+def initialize():
+    logging.info("%s> dispatcher starting", time.strftime("%X %x"))
+    logging.info("My PID is %d", os.getpid())
+
+    if utils.program_is_alive(PID_FILE_PREFIX):
+        logging.critical("scheduler already running, aborting!")
+        sys.exit(1)
+    utils.write_pid(PID_FILE_PREFIX)
+
+    if _testing_mode:
+        global_config.global_config.override_config_value(
+            DB_CONFIG_SECTION, 'database', 'stresstest_autotest_web')
+
+    os.environ['PATH'] = AUTOTEST_SERVER_DIR + ':' + os.environ['PATH']
+    global _db
+    _db = database_connection.DatabaseConnection(DB_CONFIG_SECTION)
+    _db.connect(db_type='django')
+
+    # ensure Django connection is in autocommit
+    setup_django_environment.enable_autocommit()
+    # bypass the readonly connection
+    readonly_connection.ReadOnlyConnection.set_globally_disabled(True)
+
+    logging.info("Setting signal handler")
+    signal.signal(signal.SIGINT, handle_sigint)
+
+    initialize_globals()
+    scheduler_models.initialize()
+
+    drones = global_config.global_config.get_config_value(
+        scheduler_config.CONFIG_SECTION, 'drones', default='localhost')
+    drone_list = [hostname.strip() for hostname in drones.split(',')]
+    results_host = global_config.global_config.get_config_value(
+        scheduler_config.CONFIG_SECTION, 'results_host', default='localhost')
+    _drone_manager.initialize(RESULTS_DIR, drone_list, results_host)
+
+    logging.info("Connected! Running...")
+
+
+def initialize_globals():
+    global _drone_manager
+    _drone_manager = drone_manager.instance()
 
 
 def main_without_exception_handling():
@@ -162,96 +228,25 @@ def main_without_exception_handling():
             time.sleep(scheduler_config.config.tick_pause_sec)
     except:
         email_manager.manager.log_stacktrace(
-            "Uncaught exception; terminating monitor_db")
+            "Uncaught exception; terminating scheduler")
 
     email_manager.manager.send_queued_emails()
     server.shutdown()
     _drone_manager.shutdown()
     _db.disconnect()
 
 
-def setup_logging():
-    log_dir = os.environ.get('AUTOTEST_SCHEDULER_LOG_DIR', None)
-    log_name = os.environ.get('AUTOTEST_SCHEDULER_LOG_NAME', None)
-    logging_manager.configure_logging(
-            scheduler_logging_config.SchedulerLoggingConfig(), log_dir=log_dir,
-            logfile_name=log_name)
-
-
-def handle_sigint(signum, frame):
-    global _shutdown
-    _shutdown = True
-    logging.info("Shutdown request received.")
-
-
-def initialize():
-    logging.info("%s> dispatcher starting", time.strftime("%X %x"))
-    logging.info("My PID is %d", os.getpid())
-
-    if utils.program_is_alive(PID_FILE_PREFIX):
-        logging.critical("monitor_db already running, aborting!")
-        sys.exit(1)
-    utils.write_pid(PID_FILE_PREFIX)
-
-    if _testing_mode:
-        global_config.global_config.override_config_value(
-            DB_CONFIG_SECTION, 'database', 'stresstest_autotest_web')
-
-    os.environ['PATH'] = AUTOTEST_SERVER_DIR + ':' + os.environ['PATH']
-    global _db
-    _db = database_connection.DatabaseConnection(DB_CONFIG_SECTION)
-    _db.connect(db_type='django')
-
-    # ensure Django connection is in autocommit
-    setup_django_environment.enable_autocommit()
-    # bypass the readonly connection
-    readonly_connection.ReadOnlyConnection.set_globally_disabled(True)
-
-    logging.info("Setting signal handler")
-    signal.signal(signal.SIGINT, handle_sigint)
-
-    initialize_globals()
-    scheduler_models.initialize()
-
-    drones = global_config.global_config.get_config_value(
-        scheduler_config.CONFIG_SECTION, 'drones', default='localhost')
-    drone_list = [hostname.strip() for hostname in drones.split(',')]
-    results_host = global_config.global_config.get_config_value(
-        scheduler_config.CONFIG_SECTION, 'results_host', default='localhost')
-    _drone_manager.initialize(RESULTS_DIR, drone_list, results_host)
-
-    logging.info("Connected! Running...")
-
-
-def initialize_globals():
-    global _drone_manager
-    _drone_manager = drone_manager.instance()
-
-
-def _autoserv_command_line(machines, extra_args, job=None, queue_entry=None,
-                           verbose=True):
-    """
-    @returns The autoserv command line as a list of executable + parameters.
-
-    @param machines - string - A machine or comma separated list of machines
-            for the (-m) flag.
-    @param extra_args - list - Additional arguments to pass to autoserv.
-    @param job - Job object - If supplied, -u owner and -l name parameters
-            will be added.
-    @param queue_entry - A HostQueueEntry object - If supplied and no Job
-            object was supplied, this will be used to lookup the Job object.
-    """
-    autoserv_argv = [_autoserv_path, '-p',
-                     '-r', drone_manager.WORKING_DIRECTORY]
-    if machines:
-        autoserv_argv += ['-m', machines]
-    if job or queue_entry:
-        if not job:
-            job = queue_entry.job
-        autoserv_argv += ['-u', job.owner, '-l', job.name]
-    if verbose:
-        autoserv_argv.append('--verbose')
-    return autoserv_argv + extra_args
+def main():
+    try:
+        try:
+            main_without_exception_handling()
+        except SystemExit:
+            raise
+        except:
+            logging.exception('Exception escaping in scheduler')
+            raise
+    finally:
+        utils.delete_pid_file_if_exists(PID_FILE_PREFIX)
 
 
 class Dispatcher(object):
@@ -800,7 +795,6 @@ def _process_recurring_runs(self):
             host_objects = info['hosts']
             one_time_hosts = info['one_time_hosts']
             metahost_objects = info['meta_hosts']
-            dependencies = info['dependencies']
             atomic_group = info['atomic_group']
 
             for host in one_time_hosts or []:
@@ -950,7 +944,7 @@ def _get_pidfile_info(self):
         """
         try:
             self._get_pidfile_info_helper()
-        except self._PidfileException, exc:
+        except self._PidfileException:
             self._handle_pidfile_error('Pidfile error', traceback.format_exc())
 
 
@@ -2194,7 +2188,3 @@ def epilog(self):
                                   % self.monitor.exit_code()],
                     paired_with_process=paired_process)
         self._set_all_statuses(self._final_status())
-
-
-if __name__ == '__main__':
-    main()