From f721d5be1a8fbdb55db98f21c7c70ce34817d1a7 Mon Sep 17 00:00:00 2001
From: Dominik Chilla <dominik@zwackl.de>
Date: Sat, 15 Jun 2019 00:00:58 +0200
Subject: [PATCH] Jenkins scripted multibranch pipeline

---
 Jenkinsfile                         | 24 +++++++++++++++++-------
 Jenkinsfile.declarative.multibranch | 24 +++++++++++++++++-------
 2 files changed, 34 insertions(+), 14 deletions(-)

diff --git a/Jenkinsfile b/Jenkinsfile
index 4ca56de..2d70b1d 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -4,11 +4,11 @@ pipeline {
   parameters {
     string defaultValue: 'https', name: 'dockerRegistryScheme', trim: true
     string defaultValue: 'example.com', name: 'dockerRegistryRepo', trim: true
+    string defaultValue: 'sos-milter', name: 'imageName', trim: true
   }
 
   environment {
-    dockerImage = ''
-    imageName = 'sos-milter'
+    dockerImageObj = ''
   }
 
   stages {
@@ -16,7 +16,7 @@ pipeline {
       steps {
         sh '/usr/bin/env'
         script {
-          dockerImage = docker.build(
+          dockerImageObj = docker.build(
             "${env.imageName}:${env.BRANCH_NAME}",
             "--pull --label BUILD_URL=${env.BUILD_URL} ."
           )
@@ -26,7 +26,7 @@ pipeline {
     stage('Test image') {
       steps {
         script {
-          dockerImage.inside {
+          dockerImageObj.inside {
             sh 'echo "INSIDE CONTAINER!"'
             sh '/usr/bin/env'
             sh '/bin/ps auxwwf'
@@ -38,15 +38,25 @@ pipeline {
       steps {
         script {
           docker.withRegistry("${env.dockerRegistryScheme}://${env.dockerRegistryRepo}") {
-            dockerImage.push()
+            dockerImageObj.push()
           }
         }
       }
     }
     stage('Cleanup') {
       steps {
-        sh '/usr/bin/docker rmi -f "${imageName}:${BRANCH_NAME}"'
-        sh '/usr/bin/docker rmi -f "${dockerRegistryRepo}/${imageName}:${BRANCH_NAME}"'
+        /* The default is to reuse the local images for future builds. The reason 
+           for this is quite simple! It´s much easier to prune local images from
+           disk than pushed images from the (cheap) docker registry! */
+        /* Uncomment the following directives if you want your build host to stay
+           clean from local docker images after successfull push. But, there is a 
+           caveat if you do so! Each build job produces at least one new image layer 
+           which gets pushed to the registry. This could blow up your registry after
+           a couple of time! For garbage collection check this out: 
+           https://docs.docker.com/registry/garbage-collection/ */
+        /* echo "Remove local docker images after successfull push to registry..." */
+        /* sh '/usr/bin/docker rmi -f "${imageName}:${BRANCH_NAME}"' */
+        /* sh '/usr/bin/docker rmi -f "${dockerRegistryRepo}/${imageName}:${BRANCH_NAME}"' */
       }
     }
   }
diff --git a/Jenkinsfile.declarative.multibranch b/Jenkinsfile.declarative.multibranch
index 4ca56de..2d70b1d 100644
--- a/Jenkinsfile.declarative.multibranch
+++ b/Jenkinsfile.declarative.multibranch
@@ -4,11 +4,11 @@ pipeline {
   parameters {
     string defaultValue: 'https', name: 'dockerRegistryScheme', trim: true
     string defaultValue: 'example.com', name: 'dockerRegistryRepo', trim: true
+    string defaultValue: 'sos-milter', name: 'imageName', trim: true
   }
 
   environment {
-    dockerImage = ''
-    imageName = 'sos-milter'
+    dockerImageObj = ''
   }
 
   stages {
@@ -16,7 +16,7 @@ pipeline {
       steps {
         sh '/usr/bin/env'
         script {
-          dockerImage = docker.build(
+          dockerImageObj = docker.build(
             "${env.imageName}:${env.BRANCH_NAME}",
             "--pull --label BUILD_URL=${env.BUILD_URL} ."
           )
@@ -26,7 +26,7 @@ pipeline {
     stage('Test image') {
       steps {
         script {
-          dockerImage.inside {
+          dockerImageObj.inside {
             sh 'echo "INSIDE CONTAINER!"'
             sh '/usr/bin/env'
             sh '/bin/ps auxwwf'
@@ -38,15 +38,25 @@ pipeline {
       steps {
         script {
           docker.withRegistry("${env.dockerRegistryScheme}://${env.dockerRegistryRepo}") {
-            dockerImage.push()
+            dockerImageObj.push()
           }
         }
       }
     }
     stage('Cleanup') {
       steps {
-        sh '/usr/bin/docker rmi -f "${imageName}:${BRANCH_NAME}"'
-        sh '/usr/bin/docker rmi -f "${dockerRegistryRepo}/${imageName}:${BRANCH_NAME}"'
+        /* The default is to reuse the local images for future builds. The reason 
+           for this is quite simple! It´s much easier to prune local images from
+           disk than pushed images from the (cheap) docker registry! */
+        /* Uncomment the following directives if you want your build host to stay
+           clean from local docker images after successfull push. But, there is a 
+           caveat if you do so! Each build job produces at least one new image layer 
+           which gets pushed to the registry. This could blow up your registry after
+           a couple of time! For garbage collection check this out: 
+           https://docs.docker.com/registry/garbage-collection/ */
+        /* echo "Remove local docker images after successfull push to registry..." */
+        /* sh '/usr/bin/docker rmi -f "${imageName}:${BRANCH_NAME}"' */
+        /* sh '/usr/bin/docker rmi -f "${dockerRegistryRepo}/${imageName}:${BRANCH_NAME}"' */
       }
     }
   }