在Dockerfile中命名映像有什么用

Question

In a docker file what are the uses of naming an image like so...

FROM <image> [AS <name>]

One of uses I found from the docs is -

 - Optionally a name can be given to a new build stage by adding 
AS name to the FROM instruction. The name can be used in subsequent
FROM and COPY --from=<name|index> instructions to refer to the image 
built in this stage.

Are there any other uses?

One example here which is straight forward - https://medium.com/thepeaklab/how-to-deploy-a-react-application-to-production-with-docker-multi-stage-builds-4da347f2d681

Answer 1

The name/alias is just a way to refer to a specific stage in another stage. So if you are using the normal build no need to use it. Otherwise you will be using the index number for example:

FROM <image_image>
RUN <do_something>
...

FROM <image_name>
COPY --from=0 <files_to_copy> <destination>
...

The name also can be used in conjunction with --target option to the build command for example:

FROM debian AS build-env
...

FROM alpine AS production-env
...

$ docker build -t mybuildimage --target build-env .