Proposal: TO instruction for Dockerfile

[devfacet]

Dockerfile's multiple images support could be more useful. We can use TO instruction for tagging images.

My current approach;

docker build -t="ubuntu-custom" path/to/Dockerfile
docker build -t="nodejs" path/to/Dockerfile // nodejs has instruction FROM ubuntu-custom
docker build -t="my-app" path/to/Dockerfile // myapp has instruction FROM nodejs

if we have a TO instruction then it would be like (only one Dockerfile);

docker build -t="doesn't matter" path/to/Dockerfile

FROM ubuntu
TO ubuntu-custom

ENV ...
RUN apt-get install git
RUN ...


FROM ubuntu-custom
TO nodejs

RUN apt-get install nodejs
RUN ...


FROM ubuntu-custom
TO my-app

RUN git clone url
RUN ...

docker run images

ubuntu
ubuntu-custom
nodejs
my-app

[cpuguy83]

Closing as dup of #5603

[devfacet]

@cpuguy83 : I don't understand why you closed this issue. This is not a duplicate and totally different than #5603

[cpuguy83]

@cmfatih Please explain how this is different other than the keyword that's being used?

[cpuguy83]

And also #2740

[devfacet]

Both 5603 and 2740 are not relevant to this proposal.

[jamtur01]

Hi @cmfatih - can you explain why they are not relevant and what's different about your proposal from the TAG proposal in #5603? Thanks!

[cpuguy83]

Let me re-open since I shouldn't have closed it without someone else reviewing as well.

[devfacet]

@jamtur01 & @cpuguy83 : Yup... I'm wrong this is dup.

I just see the last comment; #5603 (comment)

Each TAG instruction could tag the current layer/container as a new image. This would allow to;

Create multiple images from a single Dockerfile
Create different tags for the same image

This is exactly what I need...

@cpuguy83 : You can shut me down now :)

[cpuguy83]

Ok, thanks @cmfatih