core: add some rudimentary config file validation

conf.py

@@ -31,6 +31,32 @@ testconf = {'bot':
                         'sidrange': '8##'
                     })
            }
+
+def validateConf(conf):
+    """Validates a parsed configuration dict."""
+    assert type(conf) == dict, "Invalid configuration given: should be type dict, not %s." % type(conf).__name__
+    for section in ('bot', 'servers', 'login'):
+        assert conf.get(section), "Missing %r section in config." % section
+    for netname, serverblock in conf['servers'].items():
+        for section in ('ip', 'port', 'recvpass', 'sendpass', 'hostname',
+                        'sid', 'sidrange', 'channels', 'protocol', 'maxnicklen'):
+            assert serverblock.get(section), "Missing %r in server block for %r." % (section, netname)
+        assert type(serverblock['channels']) == list, "'channels' option in " \
+            "server block for %s must be a list, not %s." % (netname, type(serverblock['channels']).__name__)
+    assert type(conf['login'].get('password')) == type(conf['login'].get('user')) == str and \
+        conf['login']['password'] != "changeme", "You have not set the login details correctly!"
+    return conf
+
+def loadConf(fname):
+    """Loads a PyLink configuration file from the filename given."""
+    with open(fname, 'r') as f:
+        try:
+            conf = yaml.load(f)
+        except Exception as e:
+            print('ERROR: Failed to load config from %r: %s: %s' % (fname, type(e).__name__, e))
+            sys.exit(4)
+        return conf
+
 if world.testing:
     conf = testconf
     confname = 'testconf'
@@ -46,9 +72,4 @@ else:
         # we load.
         confname = 'pylink'
         fname = 'config.yml'
-    with open(fname, 'r') as f:
+    conf = validateConf(loadConf(fname))
-        try:
-            conf = yaml.load(f)
-        except Exception as e:
-            print('ERROR: Failed to load config from %r: %s: %s' % (fname, type(e).__name__, e))
-            sys.exit(4)

pylink

@@ -16,9 +16,6 @@ import coreplugin
 
 if __name__ == '__main__':
     log.info('PyLink %s starting...', world.version)
-    if conf.conf['login']['password'] == 'changeme':
-        log.critical("You have not set the login details correctly! Exiting...")
-        sys.exit(2)
     protocols_folder = [os.path.join(os.getcwd(), 'protocols')]
 
     # Write a PID file.