Allow configuration options to be specified as environment variables

6 files changed, 67 insertions, 35 deletions

diff --git a/docs/settings_file.rst b/docs/settings_file.rst
index d09f124..04fe451 100644
--- a/docs/settings_file.rst
+++ b/docs/settings_file.rst
@@ -1,7 +1,13 @@
 ##############################
 Server Settings (eventmq.conf)
 ##############################
-EventMQ uses a standard INI style config file found at ``/etc/eventmq.conf``.
+EventMQ uses a standard INI style config file with the default
+location of ``/etc/eventmq.conf``. If you would like to specify a custom path
+you can use the ``EVENTMQ_CONFIG_FILE`` environment variable.
+
+All of these options can be defined via environment variables by converting
+them to upper case and prefixing them with ``EVENTMQ_``. For example
+``EVENTMQ_MAX_SOCKETS=2048``.
 
 ******
 Global
@@ -37,7 +43,7 @@ Default: 'tcp://127.0.0.1:47291'
 The address used to listen for connections from workers
 
 wal
-=======
+===
 Default: '/var/log/eventmq/wal.log'
 
 Write-ahead Log for replaying messages received by the Router.  Will
@@ -45,7 +51,7 @@ try to create the directory specified and append to the filename given.
 Requires correct permissions to write to the given file.
 
 wal_enabled
-===============
+===========
 Default: False
 
 Enable or disable the Write-ahead Log
diff --git a/etc/eventmq.conf-dist b/etc/eventmq.conf-dist
index 9a59f2a..96dbad4 100644
--- a/etc/eventmq.conf-dist
+++ b/etc/eventmq.conf-dist
@@ -2,6 +2,9 @@
 # Enable message output at different stages in the app.
 super_debug = true
 
+# Number of maximum sockets to open per context/process.
+max_sockets = 1024
+
 # Hide the heartbeat logs when super_debug is enabled. Showing them will generate a lot of messages.
 hide_heartbeat_logs = True
 
@@ -37,4 +40,4 @@ concurrent_jobs=2
 
 [publisher]
 publisher_incoming_addr=tcp://0.0.0.0:47298
-publisher_outgoing_addr=tcp://0.0.0.0:47299
\ No newline at end of file
+publisher_outgoing_addr=tcp://0.0.0.0:47299
diff --git a/eventmq/__init__.py b/eventmq/__init__.py
index c3ffd05..ed64a39 100644
--- a/eventmq/__init__.py
+++ b/eventmq/__init__.py
@@ -1,5 +1,5 @@
 __author__ = 'EventMQ Contributors'
-__version__ = '0.3.7'
+__version__ = '0.3.8'
 
 PROTOCOL_VERSION = 'eMQP/1.0'
 
diff --git a/eventmq/tests/test_router.py b/eventmq/tests/test_router.py
index e9efa25..cf7c9ef 100644
--- a/eventmq/tests/test_router.py
+++ b/eventmq/tests/test_router.py
@@ -12,6 +12,7 @@
 #
 # You should have received a copy of the GNU Lesser General Public License
 # along with eventmq.  If not, see <http://www.gnu.org/licenses/>.
+from imp import reload
 import json
 import unittest
 
@@ -35,6 +36,10 @@ class TestCase(unittest.TestCase):
     @mock.patch('eventmq.receiver.zmq.Socket.bind')
     @mock.patch('eventmq.router.Router._start_event_loop')
     def test_start(self, event_loop_mock, zsocket_bind_mock):
+        # set the config file back to defaults. prevents tests from failing
+        # when there is a config file on the filesystem
+        reload(conf)
+
         # Test default args
         self.router.start()
         self.router.incoming.listen.assert_called_with(conf.FRONTEND_ADDR)
@@ -671,11 +676,9 @@ class TestCase(unittest.TestCase):
         self.router.process_client_message(
             (s1, '', constants.PROTOCOL_VERSION, command, msgid) +
             msg)
-        self.assertNotIn(s1, self.router.scheduler_queue,
-                         'Scheduler not '
-                         'removed. {'
-                         '}'.format(
-                             self.router.scheduler_queue))
+        self.assertNotIn(
+            s1, self.router.scheduler_queue,
+            'Scheduler not removed. {}'.format(self.router.scheduler_queue))
 
     def test_handle_kbye_from_worker(self):
         msgid = 'msg10'
diff --git a/eventmq/utils/settings.py b/eventmq/utils/settings.py
index 30c4dee..9365bff 100644
--- a/eventmq/utils/settings.py
+++ b/eventmq/utils/settings.py
@@ -16,7 +16,7 @@
 :mod:`settings` -- Settings Utilities
 =====================================
 """
-from configparser import ConfigParser
+from configparser import ConfigParser, NoOptionError
 import json
 import logging
 import os
@@ -30,26 +30,51 @@ logger = logging.getLogger(__name__)
 
 def import_settings(section='global'):
     """
-    Import settings and apply to configuration globals
+    Import settings and apply to configuration globals. This function will
+    also read from the environment variables and override any value defined
+    in the file.
 
     Args:
        section (str): Name of the INI section to import
     """
     config = ConfigParser()
 
-    if os.path.exists(conf.CONFIG_FILE):
-        config.read(conf.CONFIG_FILE)
+    config_path = os.environ.get('EVENTMQ_CONFIG_FILE', conf.CONFIG_FILE)
+    use_config_file = False
 
-        if not config.has_section(section):
+    if os.path.exists(config_path):
+        config.read(config_path)
+        if config.has_section(section):
+            use_config_file = True
+        else:
             logger.warning(
-                'Tried to read nonexistent section {}'.format(section))
-            return
+                'Tried to read nonexistent section {} from {}'.format(
+                    section, config_path))
 
-        for name, value in config.items(section):
-            if hasattr(conf, name.upper()):
-                default_value = getattr(conf, name.upper())
-                t = type(default_value)
-                if isinstance(default_value, (list, tuple)):
+        for name in dir(conf):
+            if name.startswith('_'):
+                continue
+
+            value = None
+            found_value = False
+            default_value = getattr(conf, name)
+
+            # Favor environment variables over the config file definition
+            try:
+                value = os.environ['EVENTMQ_{}'.format(name)]
+                found_value = True
+            except KeyError:
+                if use_config_file:
+                    try:
+                        value = config.get(section, name)
+                        found_value = True
+                    except NoOptionError:
+                        found_value = False
+
+            if found_value:
+                t = type(getattr(conf, name))
+
+                if t in (list, tuple):
                     try:
                         value = t(json.loads(value))
                     except ValueError:
@@ -60,19 +85,14 @@ def import_settings(section='global'):
                     # convert those elements, otherwise whatever it's type is
                     # correct
                     if isinstance(default_value[0], tuple):
-                        setattr(conf, name.upper(),
-                                t(map(tuplify, value)))
+                        setattr(conf, name, t(map(tuplify, value)))
                     else:
-                        setattr(conf, name.upper(), t(value))
+                        setattr(conf, name, t(value))
                 elif isinstance(default_value, bool):
-                    setattr(conf, name.upper(),
+                    setattr(conf, name,
                             True if 't' in value.lower() else False)
                 else:
-                    setattr(conf, name.upper(), t(value))
-                logger.debug("Setting conf.{} to {}".format(
-                    name.upper(), getattr(conf, name.upper())))
-            else:
-                logger.warning('Tried to set invalid setting: %s' % name)
-    else:
-        logger.warning('Config file at {} not found. Continuing with '
-                       'defaults.'.format(conf.CONFIG_FILE))
+                    setattr(conf, name, t(value))
+
+            logger.debug("Setting conf.{} to {}".format(
+                name, getattr(conf, name)))
diff --git a/setup.py b/setup.py
index e053544..741a517 100644
--- a/setup.py
+++ b/setup.py
@@ -7,7 +7,7 @@ from setuptools import find_packages, setup
 
 setup(
     name='eventmq',
-    version='0.3.7',
+    version='0.3.8',
     description='EventMQ job execution and messaging system based on ZeroMQ',
     packages=find_packages(),
     install_requires=['pyzmq==15.4.0',