1 files changed, 76 insertions, 0 deletions
diff --git a/compass-deck/utils/daemonize.py b/compass-deck/utils/daemonize.py
new file mode 100644
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+++ b/compass-deck/utils/daemonize.py
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+# Copyright 2014 Huawei Technologies Co. Ltd
+#
+# 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.
+
+"""Module to provider util functions in all compass code
+
+   .. moduleauthor:: Xiaodong Wang <xiaodongwang@huawei.com>
+"""
+import daemon
+import logging
+import signal
+import sys
+import time
+
+from compass.utils import flags
+
+
+flags.add_bool('daemonize',
+               help='run as daemon',
+               default=False)
+
+
+BUSY = False
+KILLED = False
+
+
+def handle_term(signum, frame):
+    """Handle sig term."""
+    global KILLED
+    logging.info('Caught signal %s in %s', signum, frame)
+    KILLED = True
+    if not BUSY:
+        sys.exit(0)
+
+
+def _daemon(callback, run_interval):
+    """help function to run callback in daemon."""
+    global BUSY
+    signal.signal(signal.SIGTERM, handle_term)
+    signal.signal(signal.SIGHUP, handle_term)
+
+    while True:
+        BUSY = True
+        callback()
+        BUSY = False
+        if KILLED:
+            logging.info('exit loop')
+            break
+
+        if run_interval > 0:
+            logging.info('will rerun after %s seconds',
+                         flags.OPTIONS.run_interval)
+            time.sleep(flags.OPTIONS.run_interval)
+        else:
+            logging.info('finish loop')
+            break
+
+
+def daemonize(callback, run_interval, **kwargs):
+    """daemonize callback and run every run_interval seconds."""
+    if flags.OPTIONS.daemonize:
+        with daemon.DaemonContext(**kwargs):
+            logging.info('run as daemon')
+            _daemon(callback, run_interval)
+    else:
+        _daemon(callback, run_interval)