Merge pull request #234 from fedora-infra/feature/warn-if-no-plugin

Feature/warn if no plugin

fedmsg/commands/tail.py

@@ -110,7 +110,6 @@ def run(self):
         self.config['mute'] = True
 
         fedmsg.init(**self.config)
-        fedmsg.meta.make_processors(**self.config)
 
         # Build a message formatter
         formatter = lambda d: d
@@ -149,6 +148,10 @@ def formatter(d):
         if self.config['packages']:
             packages = set(map(str.strip, self.config['packages'].split(',')))
 
+        # Only initialize this if we have to
+        if users or packages or self.config['terse']:
+            fedmsg.meta.make_processors(**self.config)
+
         # Spin up a zmq.Poller and yield messages
         for name, ep, topic, message in fedmsg.tail_messages(**self.config):
             if exclusive_regexp.search(topic):

fedmsg/meta/__init__.py

@@ -59,6 +59,7 @@
 from fedmsg.meta.default import DefaultProcessor
 
 import logging
+log = logging.getLogger("fedmsg")
 
 
 class ProcessorsNotInitialized(Exception):
@@ -90,13 +91,19 @@ def make_processors(**config):
         try:
             processors.append(processor.load()(_, **config))
         except Exception as e:
-            log = logging.getLogger("fedmsg")
             log.warn("Failed to load %r processor." % processor.name)
             log.warn(str(e))
 
     # This should always be last
     processors.append(DefaultProcessor(_, **config))
 
+    # By default we have three builtin processors:  Default, Logger, and
+    # Announce.  If these are the only three, then we didn't find any
+    # externally provided ones.  calls to msg2subtitle and msg2link likely will
+    # not work the way the user is expecting.
+    if len(processors) == 3:
+        log.warn("No fedmsg.meta plugins found.  fedmsg.meta.msg2* crippled")
+
 
 def msg2processor(msg, **config):
     """ For a given message return the text processor that can handle it.

fedmsg/tests/test_meta.py

@@ -51,6 +51,52 @@ def inner(self):
     return wrapper
 
 
+def skip_if_fedmsg_meta_FI_is_present(f):
+    """ A test decorator that will skip if fedmsg_meta_fedora_infrastructure
+    is installed.
+
+    The presence of that module will screw up some tests.
+    """
+    def _wrapper(self, *args, **kw):
+        try:
+            import fedmsg_meta_fedora_infrastructure
+            raise SkipTest("fedmsg_meta_FI is present")
+        except ImportError:
+            pass
+
+        return f(self, *args, **kw)
+
+    return make_decorator(f)(_wrapper)
+
+
+class TestForWarning(unittest.TestCase):
+    def setUp(self):
+        dirname = os.path.abspath(os.path.dirname(__file__))
+        self.config = fedmsg.config.load_config(
+            filenames=[os.path.join(dirname, "fedmsg-test-config.py")],
+            invalidate_cache=True,
+        )
+        self.config['topic_prefix'] = 'org.fedoraproject'
+        self.config['topic_prefix_re'] = '^org\.fedoraproject\.(dev|stg|prod)'
+
+    @skip_if_fedmsg_meta_FI_is_present
+    def test_for_no_plugins(self):
+        """ Test that we print a warning if no plugin is installed """
+        messages = []
+
+        def mocked_warning(message):
+            messages.append(message)
+
+        expected = 'No fedmsg.meta plugins found.  fedmsg.meta.msg2* crippled'
+        original = fedmsg.meta.log.warn
+        try:
+            fedmsg.meta.log.warn = mocked_warning
+            fedmsg.meta.make_processors(**self.config)
+            eq_(messages, [expected])
+        finally:
+            fedmsg.meta.log.warn = original
+
+
 class Base(unittest.TestCase):
     msg = None
     expected_title = None