Pull docker images for StackLight successively

Change-Id: I88fc7e42bb05261be9fcf655be8aeb8fa79cf586
Related-bug: #PROD-25515 (PROD:25515)
diff --git a/src/com/mirantis/mk/Orchestrate.groovy b/src/com/mirantis/mk/Orchestrate.groovy
index 50f27ab..94c6841 100644
--- a/src/com/mirantis/mk/Orchestrate.groovy
+++ b/src/com/mirantis/mk/Orchestrate.groovy
@@ -915,6 +915,13 @@
     }
 
     // Launch containers
+    // Pull images first if any
+    def listMinions = salt.getMinions(master, "I@docker:swarm and I@prometheus:server ${extra_tgt}")
+    for (int i = 0; i < listMinions.size(); i++) {
+        if (!salt.getReturnValues(salt.getPillar(master, listMinions[i], 'docker:client:images')).isEmpty()) {
+            salt.enforceState([saltId: master, target: listMinions[i], state: 'docker.client.images', retries: 2])
+        }
+    }
     salt.enforceState([saltId: master, target: "I@docker:swarm:role:master and I@prometheus:server ${extra_tgt}", state: 'docker.client'])
     salt.runSaltProcessStep(master, "I@docker:swarm and I@prometheus:server ${extra_tgt}", 'dockerng.ps')