[DNM] try build multi stage build with tempest promtool

container-images/tcib/base/os/tempest/tempest-all/tempest-all.yaml

@@ -25,3 +25,6 @@ tcib_packages:
   - qemu-img
 
 tcib_user: tempest
+tcib_builder: '{{ tempest_prometheus_image | default("quay.io/prometheus/prometheus:latest") }}'
+tcib_builder_copies:
+  /bin/promtool: /bin/promtool

roles/container_image_build/defaults/main.yml

@@ -76,3 +76,9 @@ tcib_actions: []
 
 # List of Strings, optional, <item>, Collects file from the host and stores them in the build directory.
 tcib_gather_files: []
+
+# String, Optional, 'item', Additional params to copy content from different container using buildah multi stage build, implements
+tcib_builder: ''
+
+# Dictionary, single level key:value pairs, optional, key as a source file name and value as a destination file name
+tcib_builder_copies: {}

roles/container_image_build/templates/Containerfile.j2

@@ -13,6 +13,9 @@
 # License for the specific language governing permissions and limitations
 # under the License.
 
+{% if tcib_builder | length > 0 %}
+FROM {{ tcib_builder }} as builder
+{% endif %}
 FROM {{ tcib_from }}
 {% for key, value in tcib_args.items() %}
 ARG {{ key }}={{ value | to_json }}
@@ -42,6 +45,11 @@ EXPOSE {{ item }}
 {% for item in tcib_copies %}
 COPY {{ item }}
 {% endfor %}
+{% if tcib_builder | length > 0 and tcib_builder_copies | length > 0 %}
+{% for key, value in tcib_builder_copies.items() %}
+COPY --from=builder {{ key }} {{ value }}
+{% endfor %}
+{% endif %}
 {% if tcib_shell | length > 0 %}
 SHELL {{ tcib_shell.split() | to_json }}
 {% endif %}

roles/container_image_build/templates/buildahfile.sh.j2

@@ -34,6 +34,10 @@ set -ev
 {% for key, value in tcib_args.items() %}
 export {{ key }}={{ value | to_json }}
 {% endfor %}
+{% if tcib_builder | length > 0 %}
+BUILDER_CONTAINER=$(buildah from {{ tcib_builder }})
+BUILDER_MOUNTPOINT=$(buildah mount ${BUILDER_CONTAINER})
+{% endif %}
 CONTAINER=$(buildah from {{ tcib_from }})
 MOUNTPOINT=$(buildah mount ${CONTAINER})
 {% for key, value in tcib_labels.items() %}
@@ -75,6 +79,11 @@ buildah add ${CONTAINER} {{ item }}
 {% for item in tcib_copies %}
 buildah copy ${CONTAINER} {{ item }}
 {% endfor %}
+{% if tcib_builder | length > 0 and tcib_builder_copies | length > 0 %}
+{% for key, value in tcib_builder_copies.items() %}
+buildah copy ${CONTAINER} {{ key }} {{ value }}
+{% endfor %}
+{% endif %}
 {% for item in tcib_runs %}
 {%   if item is iterable and item is not string %}
 buildah run ${CONTAINER} {{ item | join(' ') }}