[ci] Update buildah command and version

.gitlab-ci.yml

@@ -34,7 +34,8 @@ variables:
   GIT_DEPTH: 100
   CI_SERVER_NAME: "GitLab CI"
   CI_IMAGE: "paritytech/ci-linux:production"
-  BUILDAH_IMAGE: "quay.io/buildah/stable:v1.27"
+  BUILDAH_IMAGE: "quay.io/buildah/stable:v1.29"
+  BUILDAH_COMMAND: "buildah --storage-driver overlay2"
   DOCKER_OS: "debian:stretch"
   ARCH: "x86_64"
   ZOMBIENET_IMAGE: "docker.io/paritytech/zombienet:v1.3.43"
@@ -169,7 +170,7 @@ default:
     - test "$DOCKER_USER" -a "$DOCKER_PASS" ||
       ( echo "no docker credentials provided"; exit 1 )
     - cd ./artifacts
-    - buildah bud
+    - $BUILDAH_COMMAND build
       --format=docker
       --build-arg VCS_REF="${CI_COMMIT_SHA}"
       --build-arg BUILD_DATE="$(date -u '+%Y-%m-%dT%H:%M:%SZ')"
@@ -180,9 +181,9 @@ default:
     # The job will success only on the protected branch
     - echo "$DOCKER_PASS" |
       buildah login --username "$DOCKER_USER" --password-stdin docker.io
-    - buildah info
-    - buildah push --format=v2s2 "$IMAGE_NAME:$VERSION"
-    - buildah push --format=v2s2 "$IMAGE_NAME:$EXTRATAG"
+    - $BUILDAH_COMMAND info
+    - $BUILDAH_COMMAND push --format=v2s2 "$IMAGE_NAME:$VERSION"
+    - $BUILDAH_COMMAND push --format=v2s2 "$IMAGE_NAME:$EXTRATAG"
   after_script:
     - buildah logout --all