travis: Enhance Travis to do packaging jobs on different stage (#2640)

Two stages are defined in travis job: test and package,
where test runs before package. On package stage we're
going to do the packaging of final artifacts based on
centos7, centos63, ubuntu1804, ubuntu1604 and ubuntu1404.
This is to validate that no PR will break packaging artifacts.

.travis.yml

@@ -17,17 +17,21 @@
 sudo: required
 dist: trusty
 group: edge
+
 language: java
 jdk:
-- oraclejdk8
+  - oraclejdk8
 python:
   - "2.7"
+
 cache:
   directories:
-  - $HOME/.m2
+    - $HOME/.m2
   timeout: 500
+
 notifications:
   email: false
+
 env:
   global:
      - PATH=$HOME/.local/bin:$PATH
@@ -171,3 +175,46 @@ script:
 after_success: ./tools/travis/after_success.sh
 after_failure: ./tools/travis/after_failure.sh
 after_script: ./tools/travis/after_script.sh
+
+# Packaging job definition, will be reused
+.package_job: &package_job
+  before_install: docker pull ${IMAGE}
+  install: true
+  before_script: true
+  script: |
+    docker run \
+     --volume ${TRAVIS_BUILD_DIR}:/mnt/build/cloudstack \
+     --volume $HOME/.m2:/root/.m2 \
+     --rm \
+     ${IMAGE} ${PARAMS}
+  after_script: true
+  after_success: true
+  after_failure: true
+
+jobs:
+  include:
+    - stage: package
+      services: docker
+      env: IMAGE=khos2ow/cloudstack-rpm-builder:centos7 PARAMS="--distribution centos7 --pack oss"
+      <<: *package_job
+
+    - stage: package
+      services: docker
+      env: IMAGE=khos2ow/cloudstack-rpm-builder:centos6 PARAMS="--distribution centos63 --pack oss"
+      <<: *package_job
+
+    - stage: package
+      services: docker
+      env: IMAGE=khos2ow/cloudstack-deb-builder:ubuntu1804 PARAMS=""
+      <<: *package_job
+
+    - stage: package
+      services: docker
+      env: IMAGE=khos2ow/cloudstack-deb-builder:ubuntu1604 PARAMS=""
+      <<: *package_job
+
+    - stage: package
+      services: docker
+      env: IMAGE=khos2ow/cloudstack-deb-builder:ubuntu1404 PARAMS=""
+      <<: *package_job
+