Bring in ovs_config module/state

Change-Id: I32463501947d6f60e41351102365f435b63651d5
diff --git a/_states/ovs_config.py b/_states/ovs_config.py
new file mode 100644
index 0000000..bcc8ad6
--- /dev/null
+++ b/_states/ovs_config.py
@@ -0,0 +1,81 @@
+# -*- coding: utf-8 -*-
+'''
+Management of Open vSwitch configuration
+========================================
+
+The OVS config can be managed with the ovs_config state module:
+
+.. code-block:: yaml
+
+    other_config:dpdk-init:
+      ovs_config.present:
+        - value: True
+
+    other_config:dpdk-extra:
+      ovs_config.present:
+        - value: -n 12 --vhost-owner libvirt-qemu:kvm --vhost-perm 0664
+
+    external_ids:
+      ovs_config.absent
+'''
+
+
+def __virtual__():
+    '''
+    Only make these states available if Open vSwitch is installed.
+    '''
+    return 'ovs_config.list' in __salt__
+
+
+def present(name, value, wait=True):
+    '''
+    Ensures that the named config exists, eventually creates it.
+
+    Args:
+        name/value: The name/value of the config entry.
+        wait: Whether wait for ovs-vswitchd to reconfigure itself according to the modified database.
+    '''
+    ret = {'name': name, 'changes': {}, 'result': False, 'comment': ''}
+    ovs_config = __salt__['ovs_config.list']()
+
+    if name in ovs_config and ovs_config[name] == str(value).lower():
+        ret['result'] = True
+        ret['comment'] = '{0} is already set to {1}.'.format(name, value)
+    else:
+        config_updated = __salt__['ovs_config.set'](name, value, wait)
+        if config_updated:
+            ret['result'] = True
+            ret['comment'] = '{0} is updated.'.format(name)
+            ret['changes'] = { name: 'Updated to {0}'.format(value) }
+        else:
+            ret['result'] = False
+            ret['comment'] = 'Unable to update config of {0}.'.format(name)
+
+    return ret
+
+
+def absent(name):
+    '''
+    Ensures that the named config does not exist, eventually deletes it.
+
+    Args:
+        name: The name of the config entry.
+
+    '''
+    ret = {'name': name, 'changes': {}, 'result': False, 'comment': ''}
+    ovs_config = __salt__['ovs_config.list']()
+
+    if ':' in name and name not in ovs_config:
+        ret['result'] = True
+        ret['comment'] = '{0} does not exist.'.format(name)
+    else:
+        config_removed = __salt__['ovs_config.remove'](name)
+        if config_removed:
+            ret['result'] = True
+            ret['comment'] = '{0} is removed.'.format(name)
+            ret['changes'] = { name: '{0} removed'.format(name) }
+        else:
+            ret['result'] = False
+            ret['comment'] = 'Unable to delete config of {0}.'.format(name)
+
+    return ret