Add Ubuntu 12.04 as a platform to test

.travis.yml

@@ -1,17 +1,20 @@
 sudo: required
 env:
-  - >
-    container_id=$(mktemp)
-    distribution=centos
-    version=7
-    init=/usr/lib/systemd/systemd
-    run_opts="--privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro"
-  - >
-    container_id=$(mktemp)
-    distribution=ubuntu
-    version=14.04
-    init=/sbin/init
-    run_opts=""
+  - distribution: centos
+    version: 7
+    init: /usr/lib/systemd/systemd
+    run_opts: "--privileged --volume=/sys/fs/cgroup:/sys/fs/cgroup:ro"
+    container_id: $(mktemp)
+  - distribution: ubuntu
+    version: 14.04
+    init: /sbin/init
+    run_opts: ""
+    container_id: $(mktemp)
+  - distribution: ubuntu
+    version: 12.04
+    init: /sbin/init
+    run_opts: ""
+    container_id: $(mktemp)
 
 services:
   - docker
@@ -21,7 +24,7 @@ before_install:
   # Pull container
   - sudo docker pull ${distribution}:${version}
   # Customize container
-  - sudo docker build --rm=true --file=tests/Dockerfile.${distribution} --tag=${distribution}:ansible tests
+  - sudo docker build --rm=true --file=tests/Dockerfile.${distribution}-${version} --tag=${distribution}-${version}:ansible tests
 
 script:
   #
@@ -29,7 +32,7 @@ script:
   #
 
     # Run container in detached state
-  - sudo docker run --detach --volume="${PWD}":/etc/ansible/roles/role_under_test:ro ${run_opts} ${distribution}:ansible "${init}" > "${container_id}"
+  - sudo docker run --detach --volume="${PWD}":/etc/ansible/roles/role_under_test:ro ${run_opts} ${distribution}-${version}:ansible "${init}" > "${container_id}"
 
     # Syntax check
   - sudo docker exec --tty "$(cat ${container_id})" env TERM=xterm ansible-playbook /etc/ansible/roles/role_under_test/tests/test.yml --syntax-check

tests/Dockerfile.ubuntu-12.04

@@ -0,0 +1,9 @@
+FROM ubuntu:12.04
+# Install Ansible
+RUN apt-get install -y software-properties-common git
+RUN apt-add-repository -y ppa:ansible/ansible
+RUN apt-get update
+RUN apt-get install -y ansible
+# Install Ansible inventory file
+RUN echo "[local]\nlocalhost ansible_connection=local" > /etc/ansible/hosts
+