registerups: Reworked configuration parsing.

It looks more complicated, but contains error handling.

registerups/registerups.cfg.example

@@ -2,7 +2,6 @@
 # IP addres or hostname of UPS SNMP card
 address = 192.168.0.105
 # TCP port
-# default - 3052
 port = 3052
 # Secret phrase for software authentication. This value must be the
 # same as configured on the UPS web interface

registerups/registerups.py

@@ -78,30 +78,52 @@ class cps_ups:
 def help():
     print('Usage: ' + sys.argv[0] + ' <path-to-configuration-file>')
 
+configuration_structure = {'UPS': ['address',
+                                   'secret_key',
+                                   'port'],
+                           'HOST': ['ip_address',
+                                    'shutdown_time',
+                                    'delay_time',
+                                    'hostname',
+                                    'outlet_id',
+                                    'bank_id',
+                                    'isps',
+                                    'contact',
+                                    'location',
+                                    'bedt']}
 try:
     configfile = sys.argv[1]
 except IndexError:
     help()
     sys.exit(1)
-
 if not os.path.isfile(configfile):
     print('Error: configuration file ' + configfile + ' doesn\'t exists')
     sys.exit(2)
-
+configuration = {}
+try:
     config = configparser.ConfigParser()
     config.read(configfile)
+    for section in configuration_structure:
+        configuration[section] = {}
+        for param in configuration_structure[section]:
+            configuration[section][param] = config.get(section, param)
+except (configparser.NoOptionError,
+        configparser.MissingSectionHeaderError,
+        configparser.ParsingError) as err:
+    print('Configuration file parsing error:\n' + str(err))
+    sys.exit(3)
 
-u = cps_ups(address = config.get('UPS', 'address'),
-            secret_key = config.get('UPS','secret_key'),
-            port = int(config.get('UPS', 'port', fallback='3052')))
+u = cps_ups(address = configuration['UPS']['address'],
+            secret_key = configuration['UPS']['secret_key'],
+            port = int(configuration['UPS']['port']))
 
-u.register(ip_address = config.get('HOST','ip_address'),
-           shutdown_time = config.get('HOST','shutdown_time'),
-           delay_time = config.get('HOST','delay_time'),
-           hostname = config.get('HOST','hostname'),
-           outlet_id = config.get('HOST','outlet_id'),
-           bank_id = config.get('HOST','bank_id'),
-           isps = config.get('HOST','isps'),
-           contact = config.get('HOST','contact'),
-           location = config.get('HOST','location'),
-           bedt = config.get('HOST','bedt'))
+u.register(ip_address = configuration['HOST']['ip_address'],
+           shutdown_time = configuration['HOST']['shutdown_time'],
+           delay_time = configuration['HOST']['delay_time'],
+           hostname = configuration['HOST']['hostname'],
+           outlet_id = configuration['HOST']['outlet_id'],
+           bank_id = configuration['HOST']['bank_id'],
+           isps = configuration['HOST']['isps'],
+           contact = configuration['HOST']['contact'],
+           location = configuration['HOST']['location'],
+           bedt = configuration['HOST']['bedt'])