In fact, it’s not an image. It’s a list of images with arch or os labels. With the help of the list, Docker could pull the right image which matches different hosts by using the same “list name”/”image name”. Let’s get the details.

Firstly, this function is experimental. So we need to enable it in the Docker config file. A simple way is adding "experimental": "enabled" in ~/.docker/config.json.

The “list” is called the “manifest list” in official documents. When we create it, there will need a name of the list. The name will be used as a regular image name when we finish later. And the content of the list is also needed when creating. Besides, the images in the list must have been pushed to registry. The command create will check them. After pushing images, we could create a manifest list which includes these images. The command of creating operation looks like this.

  • docker manifest create m0ssc0de/wg-go-ui:v1.0.2 m0ssc0de/wg-go-ui-amd64:v1.0.2 m0ssc0de/wg-go-ui-arm64:v1.0.2

m0ssc0de/wg-go-ui:v1.0.2 the first argument after create is the name of list.

All behind the list name is the images which will be included in the list.

  • m0ssc0de/wg-go-ui-amd64:v1.0.2
  • m0ssc0de/wg-go-ui-arm64:v1.0.2

Then we need to annotate the images with different labels. Just like this. Annotate one image once.

  • docker manifest annotate m0ssc0de/wg-go-ui:v1.0.2 m0ssc0de/wg-go-ui-amd64:v1.0.2 --arch amd64
  • docker manifest annotate m0ssc0de/wg-go-ui:v1.0.2 m0ssc0de/wg-go-ui-arm64:v1.0.2 --arch arm64

Then we can check the manifest list or not.

docker manifest inspect m0ssc0de/wg-go-ui:v1.0.2

Then, we can push the list.

docker manifest push m0ssc0de/wg-go-ui:v1.0.2

If there is any error, we could see the multi-arch “image” on registry. And there is a tip from me. Add --purge to push command. This will benefit updating manifest list. By adding --purge, the manifest list will be deleted after pushing. Next time when we need to update this manifest list, we could just create a new one with new list content. If not include --purge, the create action will combine the old list and new list. The part of old list is useless for me. So we could make a simple pipeline to create a manifest list like this.

# 1. build all arch images and push
# docker push m0ssc0de/wg-go-ui-amd64:v1.0.2
# docker push m0ssc0de/wg-go-ui-arm64:v1.0.2

# 2. create manifest list
docker manifest create m0ssc0de/wg-go-ui:v1.0.2 \
		m0ssc0de/wg-go-ui-amd64:v1.0.2 \
		m0ssc0de/wg-go-ui-arm64:v1.0.2

# 3. annotate image
docker manifest annotate m0ssc0de/wg-go-ui:1.0.2 \
			m0ssc0de/wg-go-ui-amd64:v1.0.2 --arch amd64
docker manifest annotate m0ssc0de/wg-go-ui:1.0.2 \
			m0ssc0de/wg-go-ui-arm64:v1.0.2 --arch arm64

# 4. push manifest
docker manifest push m0ssc0de/wg-go-ui:1.0.2 --purge

# 5. update latest
docker manifest creat m0ssc0de/wg-go-ui:latest\
		m0ssc0de/wg-go-ui-amd64:v1.0.2 \
		m0ssc0de/wg-go-ui-arm64:v1.0.2
docker manifest push m0ssc0de/wg-go-ui:latest --purge