From 08c593bee19e0c6660c84b2a0c8477b90238a469 Mon Sep 17 00:00:00 2001
From: Michael DeHaan <michael.dehaan@gmail.com>
Date: Wed, 11 Apr 2012 21:05:46 -0400
Subject: [PATCH] Warn if no hosts matched

---
 lib/ansible/callbacks.py | 9 +++++++++
 lib/ansible/runner.py    | 1 +
 test/TestPlayBook.py     | 2 ++
 3 files changed, 12 insertions(+)

diff --git a/lib/ansible/callbacks.py b/lib/ansible/callbacks.py
index 5e8ab823fd4..0b36a62ab33 100755
--- a/lib/ansible/callbacks.py
+++ b/lib/ansible/callbacks.py
@@ -95,6 +95,9 @@ class DefaultRunnerCallbacks(object):
     def on_unreachable(self, host, res):
         pass
 
+    def on_no_hosts(self):
+        pass
+
 ########################################################################
 
 class CliRunnerCallbacks(DefaultRunnerCallbacks):
@@ -120,6 +123,9 @@ class CliRunnerCallbacks(DefaultRunnerCallbacks):
 
     def on_error(self, host, err):
         print >>sys.stderr, "stderr: [%s] => %s\n" % (host, err)
+    
+    def on_no_hosts(self):
+        print >>sys.stderr, "no hosts matched\n"
 
     def _on_any(self, host, result):
         print utils.host_report_msg(host, self.options.module_name, result, self.options.one_line)
@@ -159,6 +165,9 @@ class PlaybookRunnerCallbacks(DefaultRunnerCallbacks):
     def on_skipped(self, host):
         print "skipping: [%s]\n" % host
 
+    def on_no_hosts(self):
+        print "no hosts matched or remaining\n"
+
 ########################################################################
 
 class PlaybookCallbacks(object):
diff --git a/lib/ansible/runner.py b/lib/ansible/runner.py
index edd9763e552..3396c550266 100755
--- a/lib/ansible/runner.py
+++ b/lib/ansible/runner.py
@@ -750,6 +750,7 @@ class Runner(object):
         # find hosts that match the pattern
         hosts = self._match_hosts(self.pattern)
         if len(hosts) == 0:
+            self.callbacks.on_no_hosts()
             return dict(contacted={}, dark={})
  
         hosts = [ (self,x) for x in hosts ]
diff --git a/test/TestPlayBook.py b/test/TestPlayBook.py
index 72c0b69ccae..9e04e254320 100644
--- a/test/TestPlayBook.py
+++ b/test/TestPlayBook.py
@@ -89,6 +89,8 @@ class TestCallbacks(object):
     def on_setup_secondary(self):
         pass
 
+    def on_no_hosts(self):
+        pass
 
 class TestPlaybook(unittest.TestCase):