Raise ValueError if a config section does not exist

Instead of printing the error message and
calling sys.exit() when a section not exists
or reading the file failed rais an Exception
from readconfig. Depending on the Value or IO-Error,
the caller can decide if he wants to exit or continue.
If an Exception reaches the wsgi utilities
it bubbles all the way up.

Change-Id: Ieb444f8c34e37f49bea21c3caf1c6c2d7bee5fb4
Closes-Bug: 1578321

swift/common/daemon.py

@@ -14,6 +14,7 @@
 # limitations under the License.
 
 import os
+import sys
 import time
 import signal
 from re import sub
@@ -74,8 +75,13 @@ def run_daemon(klass, conf_file, section_name='', once=False, **kwargs):
     if section_name is '':
         section_name = sub(r'([a-z])([A-Z])', r'\1-\2',
                            klass.__name__).lower()
-    conf = utils.readconf(conf_file, section_name,
-                          log_name=kwargs.get('log_name'))
+    try:
+        conf = utils.readconf(conf_file, section_name,
+                              log_name=kwargs.get('log_name'))
+    except (ValueError, IOError) as e:
+        # The message will be printed to stderr
+        # and results in an exit code of 1.
+        sys.exit(e)
 
     # once on command line (i.e. daemonize=false) will over-ride config
     once = once or not utils.config_true_value(conf.get('daemonize', 'true'))

swift/common/utils.py

@@ -2416,6 +2416,8 @@ def readconf(conf_path, section_name=None, log_name=None, defaults=None,
                      not defined)
     :param defaults: dict of default values to pre-populate the config with
     :returns: dict of config items
+    :raises ValueError: if section_name does not exist
+    :raises IOError: if reading the file failed
     """
     if defaults is None:
         defaults = {}
@@ -2432,15 +2434,15 @@ def readconf(conf_path, section_name=None, log_name=None, defaults=None,
         else:
             success = c.read(conf_path)
         if not success:
-            print(_("Unable to read config from %s") % conf_path)
-            sys.exit(1)
+            raise IOError(_("Unable to read config from %s") %
+                          conf_path)
     if section_name:
         if c.has_section(section_name):
             conf = dict(c.items(section_name))
         else:
-            print(_("Unable to find %(section)s config section in %(conf)s") %
-                  {'section': section_name, 'conf': conf_path})
-            sys.exit(1)
+            raise ValueError(
+                _("Unable to find %(section)s config section in %(conf)s") %
+                {'section': section_name, 'conf': conf_path})
         if "log_name" not in conf:
             if log_name is not None:
                 conf['log_name'] = log_name

swift/obj/auditor.py

@@ -54,9 +54,10 @@ class AuditorWorker(object):
             # configure for their replicator
             replicator_config = readconf(self.conf['__file__'],
                                          'object-replicator')
-        except (KeyError, SystemExit):
+        except (KeyError, ValueError, IOError):
             # if we can't parse the real config (generally a KeyError on
-            # __file__, or SystemExit on no object-replicator section) we use
+            # __file__, or ValueError on no object-replicator section, or
+            # IOError if reading the file failed) we use
             # a very conservative default for rsync_timeout
             default_rsync_timeout = 86400
         else:

test/__init__.py

@@ -61,14 +61,13 @@ def get_config(section_name=None, defaults=None):
                                  '/etc/swift/test.conf')
     try:
         config = readconf(config_file, section_name)
-    except SystemExit:
+    except IOError:
         if not os.path.exists(config_file):
             print('Unable to read test config %s - file not found'
                   % config_file, file=sys.stderr)
         elif not os.access(config_file, os.R_OK):
             print('Unable to read test config %s - permission denied'
                   % config_file, file=sys.stderr)
-        else:
-            print('Unable to read test config %s - section %s not found'
-                  % (config_file, section_name), file=sys.stderr)
+    except ValueError as e:
+        print(e)
     return config

test/unit/common/middleware/crypto/test_keymaster.py

@@ -19,6 +19,7 @@ import os
 import mock
 import unittest
 
+from getpass import getuser
 from swift.common import swob
 from swift.common.middleware.crypto import keymaster
 from swift.common.middleware.crypto.crypto_utils import CRYPTO_KEY_CALLBACK
@@ -26,6 +27,7 @@ from swift.common.swob import Request
 from test.unit.common.middleware.helpers import FakeSwift, FakeAppThatExcepts
 from test.unit.common.middleware.crypto.crypto_helpers import (
     TEST_KEYMASTER_CONF)
+from test.unit import tmpfile
 
 
 def capture_start_response():
@@ -124,6 +126,14 @@ class TestKeymaster(unittest.TestCase):
         start_response, _ = capture_start_response()
         self.assertRaises(Exception, app, req.environ, start_response)
 
+    def test_missing_conf_section(self):
+        sample_conf = "[default]\nuser = %s\n" % getuser()
+        with tmpfile(sample_conf) as conf_file:
+            self.assertRaisesRegexp(
+                ValueError, 'Unable to find keymaster config section in.*',
+                keymaster.KeyMaster, self.swift, {
+                    'keymaster_config_path': conf_file})
+
     def test_root_secret(self):
         for secret in (os.urandom(32), os.urandom(33), os.urandom(50)):
             encoded_secret = base64.b64encode(secret)

test/unit/common/test_daemon.py

@@ -124,6 +124,15 @@ class TestRunDaemon(unittest.TestCase):
                 daemon.run_daemon(MyDaemon, conf_file, logger=logger)
             self.assertTrue('user quit' in sio.getvalue().lower())
 
+            # test missing section
+            sample_conf = "[default]\nuser = %s\n" % getuser()
+            with tmpfile(sample_conf) as conf_file:
+                self.assertRaisesRegexp(SystemExit,
+                                        'Unable to find my-daemon '
+                                        'config section in.*',
+                                        daemon.run_daemon, MyDaemon,
+                                        conf_file, once=True)
+
 
 if __name__ == '__main__':
     unittest.main()

test/unit/common/test_utils.py

@@ -1983,9 +1983,12 @@ log_name = yarr'''
             expected = {'__file__': conffile, 'log_name': 'section1',
                         'foo': 'bar', 'bar': 'baz'}
             self.assertEqual(result, expected)
-        self.assertRaises(SystemExit, utils.readconf, temppath, 'section3')
+
+        self.assertRaisesRegexp(
+            ValueError, 'Unable to find section3 config section in.*',
+            utils.readconf, temppath, 'section3')
         os.unlink(temppath)
-        self.assertRaises(SystemExit, utils.readconf, temppath)
+        self.assertRaises(IOError, utils.readconf, temppath)
 
     def test_readconf_raw(self):
         conf = '''[section1]
@@ -2009,7 +2012,7 @@ log_name = %(yarr)s'''
                         'section2': {'log_name': '%(yarr)s'}}
             self.assertEqual(result, expected)
         os.unlink(temppath)
-        self.assertRaises(SystemExit, utils.readconf, temppath)
+        self.assertRaises(IOError, utils.readconf, temppath)
 
     def test_readconf_dir(self):
         config_dir = {