Make gitosis-init ignore error from non-existent config file.

Refactored config file reading and logging initialization to make
things nicer.

gitosis/app.py

@@ -2,8 +2,20 @@ import os
 import sys
 import logging
 import optparse
+import errno
 import ConfigParser
 
+log = logging.getLogger('gitosis.app')
+
+class CannotReadConfigError(Exception):
+    """Unable to read config file"""
+
+    def __str__(self):
+        return '%s: %s' % (self.__doc__, ': '.join(self.args))
+
+class ConfigFileDoesNotExistError(CannotReadConfigError):
+    """Configuration does not exist"""
+
 class App(object):
     name = None
 
@@ -13,12 +25,21 @@ class App(object):
         return app.main()
 
     def main(self):
+        self.setup_basic_logging()
         parser = self.create_parser()
         (options, args) = parser.parse_args()
-        cfg = self.read_config(options)
+        cfg = self.create_config(options)
+        try:
+            self.read_config(options, cfg)
+        except CannotReadConfigError, e:
+            log.error(str(e))
+            sys.exit(1)
         self.setup_logging(cfg)
         self.handle_args(parser, cfg, options, args)
 
+    def setup_basic_logging(self):
+        logging.basicConfig()
+
     def create_parser(self):
         parser = optparse.OptionParser()
         parser.set_defaults(
@@ -31,24 +52,26 @@ class App(object):
 
         return parser
 
-    def read_config(self, options):
+    def create_config(self, options):
         cfg = ConfigParser.RawConfigParser()
+        return cfg
+
+    def read_config(self, options, cfg):
         try:
             conffile = file(options.config)
         except (IOError, OSError), e:
-            # I trust the exception has the path.
-            print >>sys.stderr, '%s: Unable to read config file: %s' \
-                  % (options.get_prog_name(), e)
-            sys.exit(1)
+            if e.errno == errno.ENOENT:
+                # special case this because gitosis-init wants to
+                # ignore this particular error case
+                raise ConfigFileDoesNotExistError(str(e))
+            else:
+                raise CannotReadConfigError(str(e))
         try:
             cfg.readfp(conffile)
         finally:
             conffile.close()
-        return cfg
 
     def setup_logging(self, cfg):
-        logging.basicConfig()
-
         try:
             loglevel = cfg.get('gitosis', 'loglevel')
         except (ConfigParser.NoSectionError,
@@ -58,9 +81,6 @@ class App(object):
             try:
                 symbolic = logging._levelNames[loglevel]
             except KeyError:
-                # need to delay error reporting until we've called
-                # basicConfig
-                log = logging.getLogger('gitosis.app')
                 log.warning(
                     'Ignored invalid loglevel configuration: %r',
                     loglevel,

gitosis/init.py

@@ -123,6 +123,13 @@ class Main(app.App):
             'Initialize a user account for use with gitosis')
         return parser
 
+    def read_config(self, *a, **kw):
+        # ignore errors that result from non-existent config file
+        try:
+            super(Main, self).read_config(*a, **kw)
+        except app.ConfigFileDoesNotExistError:
+            pass
+
     def handle_args(self, parser, cfg, options, args):
         super(Main, self).handle_args(parser, cfg, options, args)