Use declarative syntax when possible

Signed-off-by: Nicolas De Loof <nicolas.deloof@gmail.com>

Jenkinsfile

@@ -1,15 +1,55 @@
 #!groovy
 
+pipeline {
+    agent none
+
+    options {
+        skipDefaultCheckout(true)
+        buildDiscarder(logRotator(daysToKeepStr: '30'))
+        timeout(time: 2, unit: 'HOURS')
+        timestamps()
+    }
+
+    environment {
+        TAG = tag()
+        BUILD_TAG = tag()
+    }
+
+    stages {
+        stage('Build test images') {
+            parallel {
+                stage('alpine') {
+                    agent {
+                        label 'ubuntu && amd64 && !zfs'
+                    }
+                    steps {
+                        buildImage('alpine')
+                    }
+                }
+                stage('debian') {
+                    agent {
+                        label 'ubuntu && amd64 && !zfs'
+                    }
+                    steps {
+                        buildImage('debian')
+                    }
+                }
+            }
+        }
+    }
+}
+
+
 def buildImage(baseImage) {
-  def image
-  wrappedNode(label: "ubuntu && amd64 && !zfs", cleanWorkspace: true) {
-    stage("build image for \"${baseImage}\"") {
     def scmvar = checkout(scm)
     def imageName = "dockerbuildbot/compose:${baseImage}-${scmvar.GIT_COMMIT}"
     image = docker.image(imageName)
+
+    withDockerRegistry(credentialsId:'dockerbuildbot-index.docker.io') {
         try {
             image.pull()
         } catch (Exception exc) {
+            ansiColor('xterm') {
                 sh """docker build -t ${imageName} \\
                     --target build \\
                     --build-arg BUILD_PLATFORM="${baseImage}" \\
@@ -17,16 +57,14 @@ def buildImage(baseImage) {
                     .\\
                 """
                 sh "docker push ${imageName}"
+            }
             echo "${imageName}"
             return imageName
         }
     }
-  }
-  echo "image.id: ${image.id}"
-  return image.id
 }
 
-def get_versions(imageId, number) {
+def get_versions(number) {
   def docker_versions
   wrappedNode(label: "ubuntu && amd64 && !zfs") {
     docker_versions = sh(script:"""
@@ -42,7 +80,6 @@ def runTests = { Map settings ->
   def dockerVersions = settings.get("dockerVersions", null)
   def pythonVersions = settings.get("pythonVersions", null)
   def baseImage = settings.get("baseImage", null)
-  def imageName = settings.get("image", null)
 
   if (!pythonVersions) {
     throw new Exception("Need Python versions to test. e.g.: `runTests(pythonVersions: 'py37')`")
@@ -54,7 +91,8 @@ def runTests = { Map settings ->
   { ->
     wrappedNode(label: "ubuntu && amd64 && !zfs", cleanWorkspace: true) {
       stage("test python=${pythonVersions} / docker=${dockerVersions} / baseImage=${baseImage}") {
-        checkout(scm)
+        def scmvar = checkout(scm)
+        def imageName = "dockerbuildbot/compose:${baseImage}-${scmvar.GIT_COMMIT}"
         def storageDriver = sh(script: 'docker info | awk -F \': \' \'$1 == "Storage Driver" { print $2; exit }\'', returnStdout: true).trim()
         echo "Using local system's storage driver: ${storageDriver}"
         sh """docker run \\