Bug 1409

Update the snapcraft dockerfile to ensure we use the latest on
each build.

Fixes Bug 1409

Change-Id: I762f46b82c6a6c1924560b4cfda4cfe7a416ccb3
Signed-off-by: beierlm <mark.beierl@canonical.com>
diff --git a/jenkins/ci-pipelines/ci_stage_2.groovy b/jenkins/ci-pipelines/ci_stage_2.groovy
index 049763c..aa9c906 100644
--- a/jenkins/ci-pipelines/ci_stage_2.groovy
+++ b/jenkins/ci-pipelines/ci_stage_2.groovy
@@ -81,9 +81,10 @@
 
     if (fileExists('snap/snapcraft.yaml')) {
         stage('Snap build') {
+            sh "docker pull snapcore/snapcraft:stable"
             sh "sudo rm -rf ${WORKSPACE}/stage/ ${WORKSPACE}/parts/ ${WORKSPACE}/prime/ ${WORKSPACE}/*.snap"
-            sh "docker run -v ${WORKSPACE}:/build --env BRANCH=${BRANCH_NAME} -w /build snapcore/snapcraft:stable /bin/bash -c 'apt update && snapcraft'"
-            sh "sudo mv ${WORKSPACE}/${mdg}_*.snap ${WORKSPACE}/${mdg}.snap"
+            sh "snapcraft --use-lxd"
+            sh "mv ${WORKSPACE}/${mdg}_*.snap ${WORKSPACE}/${mdg}.snap"
             sh "sudo rm -rf ${WORKSPACE}/stage/ ${WORKSPACE}/parts/ ${WORKSPACE}/prime/"
 
             REV=""
@@ -100,6 +101,7 @@
             sh "sudo docker run -v ~/.snapcraft:/snapcraft -v ${WORKSPACE}:/build " +
                 "-w /build snapcore/snapcraft:stable /bin/bash -c " +
                 "\"snapcraft login --with /snapcraft/config ; snapcraft push --release=${channel}/edge${REV} ${mdg}.snap\""
+            sh "sudo rm -rf ${WORKSPACE}/*.snap"
         }
     }
 
diff --git a/jenkins/ci-pipelines/ci_stage_3.groovy b/jenkins/ci-pipelines/ci_stage_3.groovy
index 541213b..f482ee7 100644
--- a/jenkins/ci-pipelines/ci_stage_3.groovy
+++ b/jenkins/ci-pipelines/ci_stage_3.groovy
@@ -519,6 +519,7 @@
                         stage("Snap promotion") {
                             def snaps = ["osmclient"]
                             for (snap in snaps) {
+                                sh "docker pull snapcore/snapcraft:stable"
                                 channel=""
                                 if (BRANCH_NAME.startsWith("v")) {
                                     channel=BRANCH_NAME.substring(1)+"/"