Refactor image tags to be dynamic (#1120)
In order to simplify backporting and branching of new releases,
this patch relies on the Zuul branch when building images so
that we can easily branch out a new release and it will
automatically pick up the images.
diff --git a/images/keepalived/Dockerfile b/images/keepalived/Dockerfile
index 599a93c..55cb73a 100644
--- a/images/keepalived/Dockerfile
+++ b/images/keepalived/Dockerfile
@@ -12,7 +12,9 @@
# License for the specific language governing permissions and limitations
# under the License.
-FROM registry.atmosphere.dev/library/ubuntu:main
+ARG RELEASE
+
+FROM registry.atmosphere.dev/library/ubuntu:${RELEASE}
RUN <<EOF bash -xe
apt-get update -qq
apt-get install -qq -y --no-install-recommends \