Use podman for docker

.ppc64-ci.yml

@@ -14,12 +14,12 @@ variables:
   script:
     - |
       CONTAINER_IMAGE="$CONTAINER_IMAGE_BASE/$IMAGE"
-      docker login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
-      docker pull $CONTAINER_IMAGE:latest || true
-      docker build --cache-from $CONTAINER_IMAGE:latest --tag $CONTAINER_IMAGE:$CI_COMMIT_SHA --tag $CONTAINER_IMAGE:latest $IMAGE
+      podman login -u $CI_REGISTRY_USER -p $CI_REGISTRY_PASSWORD $CI_REGISTRY
+      podman pull $CONTAINER_IMAGE:latest || true
+      podman build --cache-from $CONTAINER_IMAGE:latest --tag $CONTAINER_IMAGE:$CI_COMMIT_SHA --tag $CONTAINER_IMAGE:latest $IMAGE
       if [ -z "$CI_MERGE_REQUEST_ID" ]; then
-        docker push $CONTAINER_IMAGE:$CI_COMMIT_SHA
-        docker push $CONTAINER_IMAGE:latest
+        podman push $CONTAINER_IMAGE:$CI_COMMIT_SHA
+        podman push $CONTAINER_IMAGE:latest
       fi
 
 build-ppc64le-linux-opensuse151: