Add support for checking incoming RabbitMQ version

Will be used to check if the current RabbitMQ version is high enough
before upgrading to the new one.

Change-Id: Ie133d6efc2e4c00002b8f0724e0183eaab35d1c5

Author: MoteHue

docker/rabbitmq/Dockerfile.j2

@@ -1,6 +1,6 @@
 FROM {{ namespace }}/{{ image_prefix }}base:{{ tag }}
 {% block labels %}
-LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}"
+LABEL maintainer="{{ maintainer }}" name="{{ image_name }}" build-date="{{ build_date }}" version_check=true
 {% endblock %}
 
 {% block rabbitmq_header %}{% endblock %}

docker/rabbitmq/extend_start.sh

@@ -24,3 +24,8 @@ fi
 if [[ $(stat -c %a ${RABBITMQ_LOG_DIR}) != "755" ]]; then
     chmod 755 ${RABBITMQ_LOG_DIR}
 fi
+
+if [[ "${!KOLLA_RABBITMQ_VERSION_CHECK[@]}" ]]; then
+    rabbitmqctl --version
+    exit 0
+fi