Generate bash_completion string so that we can use bash completion.

Bug #1063500

To install, copy tools/quantum.bash_completion to
/etc/bash_completion.d/quantum

Change-Id: I0afff3967c63111854455226fc90092f5bc7845a

quantumclient/shell.py

@@ -278,6 +278,24 @@ class QuantumShell(App):
 
         return parser
 
+    def _bash_completion(self):
+        """
+        Prints all of the commands and options to stdout so that the
+        quantum's bash-completion script doesn't have to hard code them.
+        """
+        commands = set()
+        options = set()
+        for option, _action in self.parser._option_string_actions.items():
+            options.add(option)
+        for command_name, command in self.command_manager:
+            commands.add(command_name)
+            cmd_factory = command.load()
+            cmd = cmd_factory(self, None)
+            cmd_parser = cmd.get_parser('')
+            for option, _action in cmd_parser._option_string_actions.items():
+                options.add(option)
+        print ' '.join(commands | options)
+
     def run(self, argv):
         """Equivalent to the main program for the application.
 
@@ -289,6 +307,9 @@ class QuantumShell(App):
             command_pos = -1
             help_pos = -1
             for arg in argv:
+                if arg == 'bash-completion':
+                    self._bash_completion()
+                    return 0
                 if arg in COMMANDS[self.api_version]:
                     if command_pos == -1:
                         command_pos = index

tools/quantum.bash_completion

@@ -0,0 +1,27 @@
+_quantum_opts="" # lazy init
+_quantum_flags="" # lazy init
+_quantum_opts_exp="" # lazy init
+_quantum()
+{
+	local cur prev nbc cflags
+	COMPREPLY=()
+	cur="${COMP_WORDS[COMP_CWORD]}"
+	prev="${COMP_WORDS[COMP_CWORD-1]}"
+
+	if [ "x$_quantum_opts" == "x" ] ; then
+		nbc="`quantum bash-completion | sed -e "s/\s-h\s/\s/"`"
+		_quantum_opts="`echo "$nbc" | sed -e "s/--[a-z0-9_-]*//g" -e "s/\s\s*/ /g"`"
+		_quantum_flags="`echo " $nbc" | sed -e "s/ [^-][^-][a-z0-9_-]*//g" -e "s/\s\s*/ /g"`"
+		_quantum_opts_exp="`echo "$_quantum_opts" | sed -e "s/\s/|/g"`"
+	fi
+
+	if [[ " ${COMP_WORDS[@]} " =~ " "($_quantum_opts_exp)" " && "$prev" != "help" ]] ; then
+		COMPLETION_CACHE=~/.quantumclient/*/*-cache
+		cflags="$_quantum_flags "$(cat $COMPLETION_CACHE 2> /dev/null | tr '\n' ' ')
+		COMPREPLY=($(compgen -W "${cflags}" -- ${cur}))
+	else
+		COMPREPLY=($(compgen -W "${_quantum_opts}" -- ${cur}))
+	fi
+	return 0
+}
+complete -F _quantum quantum