Add pipelines support

apiserver/config/default/apiserver.conf

@@ -112,6 +112,8 @@
     workers {
         # Auto-register unknown workers on status reports and other calls
         auto_register: true
+        # Assume unknow workers have unregistered (i.e. do not raise unregistered error)
+        auto_unregister: true
         # Timeout in seconds on task status update. If exceeded
         # then task can be stopped without communicating to the worker
         task_update_timeout: 600

apiserver/config/default/services/models.conf

@@ -0,0 +1,7 @@
+metadata_values {
+    # maximal amount of distinct model values to retrieve
+    max_count: 100
+
+    # cache ttl sec
+    cache_ttl_sec: 86400
+}