[enh] Allow to encode printed result in json from the cli

moulinette/__init__.py

@@ -81,7 +81,7 @@ def api(namespaces, port, routes={}, use_cache=True):
                                             'use_cache': use_cache})
     moulinette.run(port)
 
-def cli(namespaces, args, use_cache=True):
+def cli(namespaces, args, print_json=False, use_cache=True):
     """Command line interface
 
     Execute an action with the moulinette from the CLI and print its
@@ -90,6 +90,7 @@ def cli(namespaces, args, use_cache=True):
     Keyword arguments:
         - namespaces -- The list of namespaces to use
         - args -- A list of argument strings
+        - print_json -- True to print result as a JSON encoded string
         - use_cache -- False if it should parse the actions map file
             instead of using the cached one
 
@@ -100,7 +101,7 @@ def cli(namespaces, args, use_cache=True):
         moulinette = init_interface('cli',
                                     actionsmap={'namespaces': namespaces,
                                                 'use_cache': use_cache})
-        moulinette.run(args)
+        moulinette.run(args, print_json)
     except MoulinetteError as e:
         print('%s %s' % (colorize(m18n.g('error'), 'red'), e.strerror))
         return e.errno

moulinette/interfaces/cli.py

@@ -174,7 +174,7 @@ class Interface(BaseInterface):
 
         self.actionsmap = actionsmap
 
-    def run(self, args):
+    def run(self, args, print_json=False):
         """Run the moulinette
 
         Process the action corresponding to the given arguments 'args'
@@ -182,6 +182,7 @@ class Interface(BaseInterface):
 
         Keyword arguments:
             - args -- A list of argument strings
+            - print_json -- True to print result as a JSON encoded string
 
         """
         try:
@@ -189,9 +190,16 @@ class Interface(BaseInterface):
         except KeyboardInterrupt, EOFError:
             raise MoulinetteError(errno.EINTR, m18n.g('operation_interrupted'))
 
-        if isinstance(ret, dict):
+        if ret is None:
+            return
+
+        # Format and print result
+        if print_json:
+            import json
+            print(json.dumps(ret))
+        elif isinstance(ret, dict):
             pretty_print_dict(ret)
-        elif ret:
+        else:
             print(ret)