[Kubernetes] Action to scale Pod up/down

Change-Id: I6b2737524955b1f72b6a692559d3942cbb60deb7
Closes-Bug: #1449599

Kubernetes/KubernetesCluster/package/Classes/KubernetesCluster.yaml

@@ -494,3 +494,17 @@ Methods:
       - $._environment.reporter.report($this, 'Got archive from Kubernetes')
       - Return: new(std:File, base64Content => $result.content,
                     filename => 'application.tar.gz')
+
+
+  scaleRc:
+    Arguments:
+      - rcName:
+          Contract: $.string().notNull()
+      - newSize:
+          Contract: $.int().notNull()
+    Body:
+      - $template: $resources.yaml('ScaleRc.template').bind(dict(
+            rcName => $rcName,
+            newSize => $newSize
+          ))
+      - $.masterNode.instance.agent.call($template, $resources)

Kubernetes/KubernetesCluster/package/Resources/ScaleRc.template

@@ -0,0 +1,32 @@
+#  Licensed under the Apache License, Version 2.0 (the "License"); you may
+#  not use this file except in compliance with the License. You may obtain
+#  a copy of the License at
+#
+#       http://www.apache.org/licenses/LICENSE-2.0
+#
+#  Unless required by applicable law or agreed to in writing, software
+#  distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#  WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#  License for the specific language governing permissions and limitations
+#  under the License.
+
+FormatVersion: 2.0.0
+Version: 1.0.0
+Name: Scale Pod
+
+Parameters:
+  rcName: $rcName
+  newSize: $newSize
+
+Body: |
+  return scaleRc('{0} {1}'.format(args.rcName, args.newSize).stdout
+
+Scripts:
+  scaleRc:
+    Type: Application
+    Version: 1.0.0
+    EntryPoint: scale-rc.sh
+    Files: []
+    Options:
+      captureStdout: true
+      captureStderr: true

Kubernetes/KubernetesCluster/package/Resources/scripts/scale-rc.sh

@@ -0,0 +1,6 @@
+#!/bin/bash
+
+# $1 - RC name
+# $2 - new size
+
+/opt/bin/kubectl scale rc $1 --replicas=$2

Kubernetes/KubernetesPod/package/Classes/KubernetesPod.yaml

@@ -35,6 +35,7 @@ Properties:
 
   replicas:
     Contract: $.int().notNull().check($ >= 0)
+    Usage: InOut
 
 
 Methods:
@@ -303,3 +304,26 @@ Methods:
   getInternalScopeId:
     Body:
       Return: $.kubernetesCluster.id()
+
+  scalePodDown:
+    Usage: Action
+    Body:
+      - If: $.replicas > 1
+        Then:
+          - $._environment.reporter.report($this, 'Scaling Pod down')
+          - $.replicas: $.replicas - 1
+          - $.kubernetesCluster.scaleRc(rcName => $._getReplicationControllerId(), newSize => $.replicas)
+        Else:
+          - $._environment.reporter.report($this, 'Cannot scale Pod down')
+
+
+  scalePodUp:
+    Usage: Action
+    Body:
+      - If: $.replicas > 0
+        Then:
+          - $._environment.reporter.report($this, 'Scaling Pod up')
+          - $.replicas: $.replicas + 1
+          - $.kubernetesCluster.scaleRc(rcName => $._getReplicationControllerId(), newSize => $.replicas)
+        Else:
+          - $._environment.reporter.report($this, 'Cannot scale Pod up')