only scale back containers on infra change

src/platform.js

@@ -26,8 +26,6 @@ var addons = require('./addons.js'),
     tasks = require('./tasks.js'),
     _ = require('underscore');
 
-var NOOP_CALLBACK = function (error) { if (error) debug(error); };
-
 function start(callback) {
     assert.strictEqual(typeof callback, 'function');
 
@@ -45,7 +43,7 @@ function start(callback) {
     if (_.isEqual(infra, existingInfra)) {
         debug('platform is uptodate at version %s', infra.version);
 
-        onPlatformReady();
+        onPlatformReady(false /* !infraChanged */);
 
         return callback();
     }
@@ -67,7 +65,7 @@ function start(callback) {
 
         locker.unlock(locker.OP_PLATFORM_START);
 
-        onPlatformReady();
+        onPlatformReady(true /* infraChanged */);
 
         callback();
     });
@@ -77,14 +75,18 @@ function stopAllTasks(callback) {
     tasks.stopAllTasks(callback);
 }
 
-function onPlatformReady() {
-    debug('onPlatformReady: platform is ready');
+function onPlatformReady(infraChanged) {
+    debug(`onPlatformReady: platform is ready. infra changed: ${infraChanged}`);
     exports._isReady = true;
 
-    apps.schedulePendingTasks(NOOP_CALLBACK);
+    let tasks = [ apps.schedulePendingTasks ];
+    if (infraChanged) tasks.push(applyPlatformConfig, pruneInfraImages);
 
-    applyPlatformConfig(NOOP_CALLBACK);
-    pruneInfraImages(NOOP_CALLBACK);
+    async.series(async.reflectAll(tasks), function (error, results) {
+        results.forEach((result, idx) => {
+            if (result.error) debug(`Startup task at index ${idx} failed: ${result.error.message}`);
+        });
+    });
 }
 
 function applyPlatformConfig(callback) {