Added bash completion

Change-Id: I1637c8412c4068a8bd067f0366649f2bbda91052

README.rst

@@ -17,6 +17,13 @@ variable::
 
 You'll find complete documentation on the shell by running ``surveil help``.
 
+Bash completion
+~~~~~~~~~~~~~~~
+
+Basic command tab completion can be enabled by sourcing the bash completion script::
+
+    source /usr/local/share/monasca.bash_completion
+
 Python API
 ----------
 

setup.cfg

@@ -7,6 +7,8 @@ description-file =
 [files]
 packages =
     surveilclient
+data_files =
+    share = tools/surveil.bash_completion
 
 [entry_points]
 console_scripts =

surveilclient/shell.py

@@ -62,8 +62,18 @@ class SurveilShell(object):
         submodule = utils.import_versioned_module(version, 'shell')
         self._find_actions(subparsers, submodule)
         self._find_actions(subparsers, self)
+        self._add_bash_completion_subparser(subparsers)
         return parser
 
+    def _add_bash_completion_subparser(self, subparsers):
+        subparser = subparsers.add_parser(
+            'bash_completion',
+            add_help=False,
+            formatter_class=HelpFormatter
+        )
+        self.subcommands['bash_completion'] = subparser
+        subparser.set_defaults(func=self.do_bash_completion)
+
     def _find_actions(self, subparsers, actions_module):
         for attr in (a for a in dir(actions_module) if a.startswith('do_')):
             # I prefer to be hyphen-separated instead of underscores.
@@ -99,6 +109,22 @@ class SurveilShell(object):
         else:
             self.parser.print_help()
 
+    def do_bash_completion(self, args):
+        """Prints all of the commands and options to stdout.
+
+        The surveil.bash_completion script doesn't have to hard code them.
+        """
+        commands = set()
+        options = set()
+        for sc_str, sc in self.subcommands.items():
+            commands.add(sc_str)
+            for option in list(sc._optionals._option_string_actions):
+                options.add(option)
+
+        commands.remove('bash-completion')
+        commands.remove('bash_completion')
+        print(' '.join(commands | options))
+
     def main(self, argv):
         # Parse args once to find version
         parser = self.get_base_parser()
@@ -122,6 +148,9 @@ class SurveilShell(object):
         if args.func == self.do_help:
             self.do_help(args)
             return 0
+        elif args.func == self.do_bash_completion:
+            self.do_bash_completion(args)
+            return 0
 
         if not args.surveil_api_url:
             raise exc.CommandError("you must specify a Surveil API URL"