Add new Jenkins job to build multiasic vs image from 201911 branch. (s…

…onic-net#184)

Adding a new Jenkins Job to build multi-asic VS image to bring up multi-asic VS for hwsku: msft_multi_asic_vs with 6 asics.
This job will create a sonic-vs.img.gz with asic.conf updated with NUM_ASIC=6.

jenkins/vs/buildimage-multiasic-vs-image-201911/Jenkinsfile

@@ -0,0 +1,69 @@
+pipeline {
+    agent { node { label 'jenkins-kvm-workers' } }
+
+    options {
+        buildDiscarder(logRotator(artifactDaysToKeepStr: '', artifactNumToKeepStr: '', daysToKeepStr: '', numToKeepStr: '30'))
+    }
+
+    environment {
+        SONIC_TEAM_WEBHOOK = credentials('public-jenkins-builder')
+    }
+
+    triggers {
+        pollSCM('@midnight')
+    }
+
+    stages {
+        stage('Prepare') {
+            steps {
+                checkout([$class: 'GitSCM',
+                          branches: [[name: 'refs/heads/201911']],
+                          extensions: [[$class: 'SubmoduleOption',
+                                        disableSubmodules: false,
+                                        parentCredentials: false,
+                                        recursiveSubmodules: true,
+                                        reference: '',
+                                        trackingSubmodules: false],
+                                       [$class: 'LocalBranch',
+                                        localBranch: "**"]],
+                          userRemoteConfigs: [[url: 'http://github.com/Azure/sonic-buildimage']]])
+            }
+        }
+
+        stage('Build') {
+            steps {
+                sh '''#!/bin/bash -xe
+
+git submodule foreach --recursive '[ -f .git ] && echo "gitdir: $(realpath --relative-to=. $(cut -d" " -f2 .git))" > .git'
+
+make configure PLATFORM=vs
+
+sudo bash -c "echo "NUM_ASIC=6" > ./device/virtual/x86_64-kvm_x86_64-r0/asic.conf"
+
+sudo bash -c "echo 1 > /proc/sys/vm/compact_memory"
+
+make SONIC_CONFIG_BUILD_JOBS=1 target/sonic-vs.img.gz
+mv target/sonic-vs.img.gz target/sonic-multiasic-vs.img.gz
+'''
+            }
+        }
+
+    }
+    post {
+
+        success {
+            archiveArtifacts(artifacts: 'target/**')
+        }
+        fixed {
+            slackSend(color:'#00FF00', message: "Build job back to normal: ${env.JOB_NAME} ${env.BUILD_NUMBER} (<${env.BUILD_URL}|Open>)")
+            office365ConnectorSend(webhookUrl: "${env.SONIC_TEAM_WEBHOOK}")
+        }
+        regression {
+            slackSend(color:'#FF0000', message: "Build job Regression: ${env.JOB_NAME} ${env.BUILD_NUMBER} (<${env.BUILD_URL}|Open>)")
+            office365ConnectorSend(webhookUrl: "${env.SONIC_TEAM_WEBHOOK}")
+        }
+        cleanup {
+            cleanWs(disableDeferredWipeout: false, deleteDirs: true, notFailBuild: true)
+        }
+    }
+}