Container left if docker build fails

General
,
1

I’m using docker build to compile software and tag the final image, ready to run later.
When the docker build completes successfully the container the build ran in is removed - that seems to be the right thing to do.
When the compile fails and the docker build does not complete then the container is left - that seems to be the wrong thing to do.

Is there a specific reason why the container is left? It seems pointless, but perhaps I’m missing something.

I think this is especially pertinent since ^C during a docker build now stops and removes the container.

$ docker version
Client:
 Version:      1.12.0-rc4
 API version:  1.24
 Go version:   go1.6.2
 Git commit:   e4a0dbc
 Built:        Wed Jul 13 03:28:51 2016
 OS/Arch:      darwin/amd64
 Experimental: true

Server:
 Version:      1.12.0-rc4
 API version:  1.24
 Go version:   go1.6.2
 Git commit:   e4a0dbc
 Built:        Wed Jul 13 03:28:51 2016
 OS/Arch:      linux/amd64
 Experimental: true
2

If some of your container build steps failed - docker leave container too, so it is not related to ^C during container build.

3

Hi @Nickdoikov,

You appear to be agreeing with the point of my message as a whole - when the build fails the container is left.

I was bringing up ^C during the build because that is a recent change (for the better) demonstrating that user intervention during a build removes the container, so I suggest that failure during a build should remove the container too.

Unless anyone can tell me a good reason why the build container is useful after the build has failed?

4

in fact Dockerfile is a scenario applied to basic image (in most cases).
when you run “docker build” it perform steps from Dockerfile to basic image , tag container, pack it into the image and delete container.
So if scenario failed - partial image left because of base build process unfinished and tag step as well as other subsequent steps will not performed.

It works same way all time i use docker (from 1.5 or 1.4 as i remember).