Factor out entry point helper and apply to marconi.cmd.server

Change-Id: I3be826366948348430ebd286527ead5fec6413b9

marconi/cmd/gc.py

@@ -14,13 +14,12 @@
 # See the License for the specific language governing permissions and
 # limitations under the License.
 
-import atexit
 import random
 import sys
-import termios
 import time
 
 from marconi import bootstrap
+from marconi.common import cli
 from marconi.common import config
 from marconi.openstack.common import log as logging
 
@@ -28,34 +27,7 @@ PROJECT_CFG = config.project('marconi')
 LOG = logging.getLogger(__name__)
 
 
-def _fail(returncode, ex):
+@cli.runnable
-    """Handles terminal errors.
-
-    :param returncode: process return code to pass to sys.exit
-    :param ex: the error that occurred
-    """
-
-    LOG.exception(ex)
-    sys.stderr.write('ERROR: %s\n' % ex)
-    sys.exit(returncode)
-
-
-def _enable_echo(enable):
-    """Enables or disables terminal echo.
-
-    :param enable: pass True to enable echo, False to disable
-    """
-
-    fd = sys.stdin.fileno()
-    new = termios.tcgetattr(fd)
-    if enable:
-        new[3] |= termios.ECHO
-    else:
-        new[3] &= ~termios.ECHO
-
-    termios.tcsetattr(fd, termios.TCSANOW, new)
-
-
 def run():
     """Entry point to start marconi-gc.
 
@@ -66,13 +38,7 @@ def run():
           or interrupted.
     """
 
-    atexit.register(_enable_echo, True)
-    _enable_echo(False)
-
     try:
-        logging.setup('marconi')
-        PROJECT_CFG.load(args=sys.argv[1:])
-
         info = _('Starting marconi-gc')
         print(info + _('. Use CTRL+C to exit...\n'))
         LOG.info(info)
@@ -95,9 +61,3 @@ def run():
 
         LOG.exception(ex)
         print('')
-
-    except KeyboardInterrupt:
-        LOG.info('Terminating marconi-gc')
-
-    except Exception as ex:
-        _fail(1, ex)

marconi/cmd/server.py

@@ -16,18 +16,10 @@
 import sys
 
 from marconi import bootstrap
+from marconi.common import cli
 
 
-def fail(returncode, e):
+@cli.runnable
-    sys.stderr.write('ERROR: %s\n' % e)
-    sys.exit(returncode)
-
-
 def run():
-    try:
+    server = bootstrap.Bootstrap(cli_args=sys.argv[1:])
-        server = bootstrap.Bootstrap(cli_args=sys.argv[1:])
+    server.run()
-        server.run()
-    except KeyboardInterrupt:
-        fail(1, '... terminating marconi')
-    except RuntimeError as e:
-        fail(1, e)

marconi/common/cli.py

@@ -0,0 +1,77 @@
+# Copyright (c) 2013 Rackspace Hosting, Inc.
+#
+# 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.
+
+import atexit
+import functools
+import sys
+import termios
+
+from marconi.common import config
+from marconi.openstack.common import log as logging
+
+PROJECT_CFG = config.project('marconi')
+LOG = logging.getLogger(__name__)
+
+
+def _fail(returncode, ex):
+    """Handles terminal errors.
+
+    :param returncode: process return code to pass to sys.exit
+    :param ex: the error that occurred
+    """
+
+    LOG.exception(ex)
+    sys.exit(returncode)
+
+
+def _enable_echo(enable):
+    """Enables or disables terminal echo.
+
+    :param enable: pass True to enable echo, False to disable
+    """
+
+    fd = sys.stdin.fileno()
+    new_attr = termios.tcgetattr(fd)
+    if enable:
+        new_attr[3] |= termios.ECHO
+    else:
+        new_attr[3] &= ~termios.ECHO
+
+    termios.tcsetattr(fd, termios.TCSANOW, new_attr)
+
+
+def runnable(func):
+    """Entry point wrapper.
+
+    Note: This call blocks until the process is killed
+          or interrupted.
+    """
+
+    @functools.wraps(func)
+    def _wrapper():
+        atexit.register(_enable_echo, True)
+        _enable_echo(False)
+
+        try:
+            logging.setup('marconi')
+            PROJECT_CFG.load(args=sys.argv[1:])
+            func()
+        except KeyboardInterrupt:
+            LOG.info('Terminating')
+        except Exception as ex:
+            _fail(1, ex)
+
+    return _wrapper