Add metadata to image

Also, pin base image to a specific version instead of `latest`.

Signed-off-by: Chris Evich <chris_gitlab@icuc.me>

.gitlab-ci.yml

@@ -37,4 +37,8 @@ build:
             --dockerfile $CI_PROJECT_DIR/Containerfile \
             --destination "${CI_REGISTRY_IMAGE}:${IMAGE_TAG}" \
             --build-arg "BASE_TAG=$BASE_TAG" \
-            --build-arg "FLAVOR=$FLAVOR"
+            --build-arg "FLAVOR=$FLAVOR" \
+            --label "org.opencontainers.image.revision=$CI_COMMIT_SHA" \
+            --label "org.opencontainers.artifact.created=$CI_JOB_STARTED_AT" \
+            --label "org.opencontainers.image.created=$CI_JOB_STARTED_AT" \
+            --label "org.opencontainers.image.version=${IMAGE_TAG}"