The following paths are now implict and optional in vars_files:

./group_vars/groupname.yml (for all groups the host is in)
./host_vars/hostname.yml (for the hostname given in the inventory)

This requires an actual inventory file, not script and the paths are relative
to the directory of the inventory file.

CHANGELOG.md

@@ -31,6 +31,7 @@ Ansible Changes By Release
 * mount module
 * apt module now passes DEBIAN_FRONTEND=noninteractive
 * to catch typos, like 'var' for 'vars', playbooks and tasks now yell on invalid parameters
+* automatically load (directory_of_inventory_file)/group_vars/groupname and /host_vars/hostname in vars_files
 
 0.5 "Amsterdam" ------- July 04, 2012
 

lib/ansible/inventory/__init__.py

@@ -80,6 +80,7 @@ class Inventory(object):
     def _match(self, str, pattern_str):
         return fnmatch.fnmatch(str, pattern_str)
 
+    # TODO: cache this logic so if called a second time the result is not recalculated
     def get_hosts(self, pattern="all"):
         """ Get all host objects matching the pattern """
         hosts = {}
@@ -107,6 +108,8 @@ class Inventory(object):
     def get_groups(self):
         return self.groups
 
+    # TODO: cache this logic so if called a second time the result is not recalculated
+    # if using inventory scripts
     def get_host(self, hostname):
         for group in self.groups:
             for host in group.get_hosts():
@@ -120,12 +123,16 @@ class Inventory(object):
                 return group
         return None
 
+    # TODO: cache this logic so if called a second time the result is not recalculated
+    # if using inventory scripts
     def get_group_variables(self, groupname):
         group = self.get_group(groupname)
         if group is None:
             raise Exception("group not found: %s" % groupname)
         return group.get_variables()
 
+    # TODO: cache this logic so if called a second time the result is not recalculated
+    # if using inventory scripts
     def get_variables(self, hostname):
 
         if self._is_script:
@@ -169,3 +176,15 @@ class Inventory(object):
         """ Do not restrict list operations """
 
         self._restriction = None
+
+    def is_file(self):
+        """ did inventory come from a file? """
+        if not isinstance(self.host_list, basestring):
+            return False
+        return os.path.exists(self.host_list)
+
+    def basedir(self):
+        """ if inventory came from a file, what's the directory? """
+        if not self.is_file():
+            return None
+        return os.path.dirname(self.host_list)

lib/ansible/playbook/play.py

@@ -203,6 +203,21 @@ class Play(object):
         if type(self.vars_files) != list:
             self.vars_files = [ self.vars_files ]
 
+  
+        if (host is not None):
+            inventory = self.playbook.inventory
+            hostrec = inventory.get_host(host)
+            groups = [ g.name for g in hostrec.groups ]
+            basedir = inventory.basedir()
+            if basedir is not None:
+                for x in groups:
+                    path = os.path.join(basedir, "group_vars/%s" % x)
+                    if os.path.exists(path):
+                        self.vars_files.append(path)
+                path = os.path.join(basedir, "host_vars/%s" % hostrec.name)
+                if os.path.exists(path):
+                    self.vars_files.append(path)
+
         for filename in self.vars_files:
 
             if type(filename) == list: