How to push a single image with multiple tags to a container registry? - ibm-cloud

Question

I'm currently using the following command to build an image with a tag:
buildctl build \
--frontend dockerfile.v0 --opt filename=${DOCKER_FILE} --local dockerfile=${DOCKER_ROOT} \
${BUILD_ARGS} --local context=${DOCKER_ROOT} \
--import-cache type=registry,ref=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME} \
--output type=image,name="${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:${IMAGE_TAG}",push=true
I want to add a new tag to the same image. I've tried what is suggested on Buildctl command to tag multiple images, but it fails.
buildctl build \
--frontend dockerfile.v0 --opt filename=${DOCKER_FILE} --local dockerfile=${DOCKER_ROOT} \
${BUILD_ARGS} --local context=${DOCKER_ROOT} \
--import-cache type=registry,ref=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME} \
--output type=image,name="${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:${IMAGE_TAG},${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:latest",push=true
error: invalid value acme.com/namespace/image-name:latest
I also tried the following, but it only creates the image with the latest tag, not both
buildctl build \
--frontend dockerfile.v0 --opt filename=${DOCKER_FILE} --local dockerfile=${DOCKER_ROOT} \
${BUILD_ARGS} --local context=${DOCKER_ROOT} \
--import-cache type=registry,ref=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME} \
--output type=image,name="${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:${IMAGE_TAG},name=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:latest",push=true
What I want:
1 image with 2 tags: value of IMAGE_TAG and latest
Does anyone know how to do it?

Answer 1

There seems to be a difference between name="foo" and "name=foo". The correct one in this case is the latter.
I tracked the issue that enabled this funcitonality https://github.com/moby/buildkit/issues/797. The comments show how to do it (depending on your environment escaping might be necessary; although, not always).
Following the scenario from the question, the propper way to build and push a single image with multiple tags is as follows (notice how it's "name=)
buildctl build \
--frontend dockerfile.v0 --opt filename=${DOCKER_FILE} --local dockerfile=${DOCKER_ROOT} \
${BUILD_ARGS} --local context=${DOCKER_ROOT} \
--import-cache type=registry,ref=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME} \
--output type=image,\"name=${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:${IMAGE_TAG},${REGISTRY_URL}/${REGISTRY_NAMESPACE}/${IMAGE_NAME}:latest\",push=true