Add a "-o" override option so hosts not in a playbook can still be managed by a playbook.

bin/ansible-playbook

@@ -50,6 +50,8 @@ def main(args):
         help="ask for SSH password")
     parser.add_option("-M", "--module-path", dest="module_path",
         help="path to module library", default=C.DEFAULT_MODULE_PATH)
+    parser.add_option('-o', '--override-hosts', dest="override_hosts", default=None,
+        help="run playbook against these hosts regardless of inventory settings")
     parser.add_option('-T', '--timeout', default=C.DEFAULT_TIMEOUT, type='int',
         dest='timeout', help="set the SSH timeout in seconds")
 
@@ -62,6 +64,9 @@ def main(args):
     sshpass = None
     if options.ask_pass:
         sshpass = getpass.getpass(prompt="SSH password: ")
+    override_hosts = None
+    if options.override_hosts:
+        override_hosts = options.override_hosts.split(",")
 
     # run all playbooks specified on the command line
     for playbook in args:
@@ -73,7 +78,8 @@ def main(args):
             verbose=True,
             remote_pass=sshpass,
             callbacks=callbacks.PlaybookCallbacks(),
-            timeout=options.timeout
+            timeout=options.timeout,
+            override_hosts=override_hosts,
         )
         try:
             results = pb.run()

lib/ansible/playbook.py

@@ -54,6 +54,7 @@ class PlayBook(object):
         timeout        = C.DEFAULT_TIMEOUT,
         remote_user    = C.DEFAULT_REMOTE_USER,
         remote_pass    = C.DEFAULT_REMOTE_PASS,
+        override_hosts = None,
         verbose        = False,
         callbacks      = None):
 
@@ -65,6 +66,7 @@ class PlayBook(object):
         self.remote_pass    = remote_pass
         self.verbose        = verbose
         self.callbacks      = callbacks
+        self.override_hosts = override_hosts
         self.callbacks.set_playbook(self)
 
         # store the list of changes/invocations/failure counts
@@ -83,7 +85,8 @@ class PlayBook(object):
         self.basedir = os.path.dirname(playbook)
         self.playbook = self._parse_playbook(playbook)
 
-        self.host_list, self.groups = ansible.runner.Runner.parse_hosts(host_list)
+        self.host_list, self.groups = ansible.runner.Runner.parse_hosts(
+            host_list, override_hosts=self.override_hosts)
     
     # *****************************************************
 
@@ -499,7 +502,11 @@ class PlayBook(object):
         ''' run a list of tasks for a given pattern, in order '''
 
         # get configuration information about the pattern
-        pattern  = pg['hosts']
+        pattern  = pg.get('hosts',None)
+        if self.override_hosts:
+            pattern = 'all'
+        if pattern is None:
+            raise errors.AnsibleError('hosts declaration is required')
 
         vars       = self._get_vars(pg, self.basedir)
         vars_files = pg.get('vars_files', {})

lib/ansible/runner.py

@@ -149,9 +149,14 @@ class Runner(object):
     # *****************************************************
 
     @classmethod
-    def parse_hosts(cls, host_list):
+    def parse_hosts(cls, host_list, override_hosts=None):
         ''' parse the host inventory file, returns (hosts, groups) '''
 
+        if override_hosts is not None:
+            if type(override_hosts) != list:
+                raise errors.AnsibleError("override hosts must be a list")
+            return (override_hosts, dict(ungrouped=override_hosts))
+
         if type(host_list) == list:
             raise Exception("function can only be called on inventory files")