feat(publisher): add http liveness health check

Author: Matthew

api/models.py

@@ -1159,6 +1159,34 @@ def _etcd_purge_cert(**kwargs):
         pass
 
 
+def _etcd_publish_config(**kwargs):
+    config = kwargs['instance']
+    # we purge all existing config when adding the newest instance. This is because
+    # deis config:unset would remove an existing value, but not delete the
+    # old config object
+    try:
+        _etcd_client.delete('/deis/config/{}'.format(config.app),
+                            prevExist=True, dir=True, recursive=True)
+    except KeyError:
+        pass
+    if kwargs['created']:
+        for k, v in config.values.iteritems():
+            _etcd_client.write(
+                '/deis/config/{}/{}'.format(
+                    config.app,
+                    unicode(k).encode('utf-8').lower()),
+                unicode(v).encode('utf-8'))
+
+
+def _etcd_purge_config(**kwargs):
+    config = kwargs['instance']
+    try:
+        _etcd_client.delete('/deis/config/{}'.format(config.app),
+                            prevExist=True, dir=True, recursive=True)
+    except KeyError:
+        pass
+
+
 def _etcd_publish_domains(**kwargs):
     domain = kwargs['instance']
     if kwargs['created']:
@@ -1204,3 +1232,5 @@ def create_auth_token(sender, instance=None, created=False, **kwargs):
     post_delete.connect(_etcd_purge_app, sender=App, dispatch_uid='api.models')
     post_save.connect(_etcd_publish_cert, sender=Certificate, dispatch_uid='api.models')
     post_delete.connect(_etcd_purge_cert, sender=Certificate, dispatch_uid='api.models')
+    post_save.connect(_etcd_publish_config, sender=Config, dispatch_uid='api.models')
+    post_delete.connect(_etcd_purge_config, sender=Config, dispatch_uid='api.models')