Cmdline arg -c sets main configuration file (old paths.conf) instead of dir containing it

It has been notified that current configuration system is difficult to
understand and to use, so it has been envisioned to refactor it a bit.
The idea is that the user passes a -c path/to/main.conf file, which in
turn contains whatever osmo-gsm-tester main settings supports (basically
what old paths.conf used to be, plus some files harcoded to the same -c
directory are now configurable through the main configuration file).

Change-Id: Ieca65b71b543c44cfcec8e83efd0fe053c432e55
diff --git a/src/osmo-gsm-tester.py b/src/osmo-gsm-tester.py
index fb5574b..204b1c7 100755
--- a/src/osmo-gsm-tester.py
+++ b/src/osmo-gsm-tester.py
@@ -24,9 +24,9 @@
 
 Examples:
 
-./osmo-gsm-tester.py -c doc/examples/2g_osmocom/ ~/my_trial_package/ -s osmo_trx
-./osmo-gsm-tester.py -c doc/examples/2g_osmocom/ ~/my_trial_package/ -s sms_tests:dyn_ts+eu_band+bts_sysmo
-./osmo-gsm-tester.py -c sysmocom/ ~/my_trial_package/ -s sms_tests/mo_mt_sms:bts_trx
+./osmo-gsm-tester.py -c doc/examples/2g_osmocom/main.conf ~/my_trial_package/ -s osmo_trx
+./osmo-gsm-tester.py -c doc/examples/2g_osmocom/main.conf ~/my_trial_package/ -s sms_tests:dyn_ts+eu_band+bts_sysmo
+./osmo-gsm-tester.py -c sysmocom/main.conf ~/my_trial_package/ -s sms_tests/mo_mt_sms:bts_trx
 
 (The names for test suites and scenarios used in these examples must be defined
 by the osmo-gsm-tester configuration.)
@@ -54,8 +54,9 @@
 A test run thus needs to define:
 * A trial package containing built binaries
 * A set of test suites, each with its combinations of scenarios
-* A configuration directory specifying sets of resources, default configurations
-  and paths on where to find suites, scenarios, etc.
+* A main configuration file specifying paths to other files containing sets of
+  resources, default configurations and paths on where to find suites,
+  scenarios, etc.
 
 If no combination of suites and scenarios is provided, the default list of
 suites will be run as defined in the osmo-gsm-tester configuration.
@@ -101,8 +102,8 @@
     # is easiest to maintain.
     parser.add_argument('-V', '--version', action='store_true',
             help='Show version')
-    parser.add_argument('-c', '--conf-dir', dest='conf_dir',
-            help='''Specify configuration directory path (containing paths.conf)''')
+    parser.add_argument('-c', '--conf-path', dest='conf_path',
+            help='''Specify main configuration file path''')
     parser.add_argument('trial_package',
             help='Directory containing binaries to test')
     parser.add_argument('-s', '--suite-scenario', dest='suite_scenario', action='append',
@@ -140,18 +141,18 @@
         log.style_change(trace=True)
     if args.source:
         log.style_change(src=True)
-    if args.conf_dir:
-        config.override_conf = args.conf_dir
+    if args.conf_path:
+        config.override_conf = args.conf_path
 
     combination_strs = list(args.suite_scenario or [])
 
     if not combination_strs:
-        combination_strs = config.read_config_file(config.DEFAULT_SUITES_CONF, if_missing_return=[])
+        combination_strs = config.read_config_file(config.CFG_DEFAULT_SUITES_CONF, if_missing_return=[])
 
         if combination_strs:
             print('Running default suites:\n  ' + ('\n  '.join(combination_strs)))
         else:
-            print('No default suites configured (%r)' % config.DEFAULT_SUITES_CONF)
+            print('Failed to load default suites (%r)' % config.get_main_config_value(config.DEFAULT_SUITES_CONF, fail_if_missing=False))
 
 
     if not combination_strs: