better argument treatment

base.py

@@ -251,7 +251,7 @@ class ServiceManager:
         if not self.stop(ins, service):
             print('nothing to stop')
 
-    def prepare_start(self, ins, service):
+    def prepare_start(self, ins, service, cfg=''):
         if ins not in self.env:
             self.get_info()
         gr = self.group.upper()
@@ -300,12 +300,15 @@ class ServiceManager:
                 if not cmd:
                     if restart and service is None:
                         continue  # silently ignore missing cfg when restarting all services
-                    raise ValueError('missing cfg for %s %s' % (ins, service_i))
+                    raise UsageError('missing cfg for %s %s' % (ins, service_i))
             wd = os.getcwd()
             try:
-                start_dir, env = self.prepare_start(ins, service_i)
+                start_dir, env = self.prepare_start(ins, service_i, cfg)
                 env = dict(os.environ, **env)
                 os.chdir(start_dir)
+                if start_dir not in sys.path:
+                    sys.path.insert(0, start_dir)
+                print('SYSPATH', sys.path)
                 if wait:
                     proc = subprocess.Popen(cmd.split(), env=env)
                     proc.wait()
@@ -353,7 +356,10 @@ class ServiceManager:
     def do_run(self, ins, service=None, cfg=None):
         """for tests: run and wait"""
         if not service:
-            service, = self.services
+            try:
+                service, = self.services
+            except ValueError:
+                raise UsageError('need service to start (one of %s)' % ', '.join(self.services))
         self.do_start(ins, service, cfg, wait=True)
 
     def do_list(self, ins=None, *args):
@@ -417,10 +423,19 @@ class ServiceManager:
                 raise UsageError(errtxt)
             raise
 
-    def usage(self):
+    def do_help(self, *args):
         if self.main_ins:
             usage = self.USAGE.replace(' <instance>', '').replace(' [<instance>]', '') % ''
         else:
             usage = self.USAGE % ('<instance> is one of %s' %  ', '.join(self.info))
         print(usage)
 
+    def treat_args(self, argdict, unknown=(), extra=()):
+        if unknown:
+            raise UsageError('unknown argument: %s' % (' '.join(unknown)))
+        if extra:
+            return [argdict.get('ins'), argdict.get('service')] + extra
+        args = [argdict.get('ins'), argdict.get('service')]
+        while args and not args[-1]:
+            args.pop()
+        return args