diff --git a/os_config_applier/os_config_applier.py b/os_config_applier/os_config_applier.py
index 172701c..0928b6b 100755
--- a/os_config_applier/os_config_applier.py
+++ b/os_config_applier/os_config_applier.py
@@ -48,7 +48,8 @@ def print_key(config_path, key, type_name):
         try:
             config = config[key]
         except KeyError:
-            raise KeyError('key %s does not exist in %s' % (key, config_path))
+            raise ConfigException(
+                'key %s does not exist in %s' % (key, config_path))
     ensure_type(config, type_name)
     print config
 
@@ -197,10 +198,11 @@ def main(argv=sys.argv):
             logger.info("success")
     except ConfigException as e:
         logger.error(e)
-        sys.exit(1)
-    sys.exit(0)
+        return 1
+    return 0
 
-# logginig
+
+# logging
 LOG_FORMAT = '[%(asctime)s] [%(levelname)s] %(message)s'
 DATE_FORMAT = '%Y/%m/%d %I:%M:%S %p'
 
@@ -210,6 +212,6 @@ def add_handler(logger, handler):
     logger.addHandler(handler)
 logger = logging.getLogger('os-config-applier')
 logger.setLevel(logging.INFO)
-add_handler(logger, logging.StreamHandler(sys.stdout))
+add_handler(logger, logging.StreamHandler())
 if os.geteuid() == 0:
     add_handler(logger, logging.FileHandler('/var/log/os-config-applier.log'))
diff --git a/os_config_applier/tests/test_os_config_applier.py b/os_config_applier/tests/test_os_config_applier.py
index 5292a70..71305cd 100644
--- a/os_config_applier/tests/test_os_config_applier.py
+++ b/os_config_applier/tests/test_os_config_applier.py
@@ -15,7 +15,6 @@
 
 import json
 import os
-import subprocess
 import tempfile
 
 import fixtures
@@ -76,34 +75,39 @@ class TestRunOSConfigApplier(testtools.TestCase):
         self.useFixture(fixtures.MonkeyPatch('sys.stdout', self.stdout))
         stderr = self.useFixture(fixtures.StringStream('stderr')).stream
         self.useFixture(fixtures.MonkeyPatch('sys.stderr', stderr))
+        self.logger = self.useFixture(
+            fixtures.FakeLogger(name="os-config-applier"))
         fd, self.path = tempfile.mkstemp()
         with os.fdopen(fd, 'w') as t:
             t.write(json.dumps(CONFIG))
             t.flush()
 
     def test_print_key(self):
-        oca.main(['os-config-applier.py', '--metadata', self.path, '--key',
-                  'database.url', '--type', 'raw'])
+        self.assertEqual(0, oca.main(
+            ['os-config-applier.py', '--metadata', self.path, '--key',
+             'database.url', '--type', 'raw']))
         self.stdout.seek(0)
         self.assertEqual(CONFIG['database']['url'],
                          self.stdout.read().strip())
+        self.assertEqual('', self.logger.output)
 
     def test_print_key_missing(self):
-        self.assertRaises(
-            subprocess.CalledProcessError, oca.main,
+        self.assertEqual(1, oca.main(
             ['os-config-applier.py', '--metadata', self.path, '--key',
-             'does.not.exist'])
+             'does.not.exist']))
+        self.assertIn('does not exist', self.logger.output)
 
     def test_print_key_wrong_type(self):
-        self.assertRaises(
-            subprocess.CalledProcessError, oca.main,
+        self.assertEqual(1, oca.main(
             ['os-config-applier.py', '--metadata', self.path, '--key',
-             'x', '--type', 'int'])
+             'x', '--type', 'int']))
+        self.assertIn('cannot interpret value', self.logger.output)
 
     def test_print_templates(self):
         oca.main(['os-config-applier', '--print-templates'])
         self.stdout.seek(0)
         self.assertEqual(self.stdout.read().strip(), oca.TEMPLATES_DIR)
+        self.assertEqual('', self.logger.output)
 
 
 class OSConfigApplierTestCase(testtools.TestCase):
diff --git a/requirements.txt b/requirements.txt
index 7bd15e8..a9f8240 100644
--- a/requirements.txt
+++ b/requirements.txt
@@ -1,4 +1,5 @@
 anyjson
+argparse
 d2to1
 pbr
 pystache