Packer: Docker build leaves container behind if error occurs

[jacek99]

I tried to provison a basic Docker instance

    {
        "type": "docker",
        "image": "tianon/centos:6.5",
        "export_path": "vm.tar",
        "run_command": ["run", "-m=8g","-c=0","-d", "-i", "-t", "-v", "{{.Volumes}}", "{{.Image}}", "/bin/bash"]
    }

A shell script provision that I had failed and it resulted in an error like this:

docker: Could not retrieve mirrorlist http://mirrorlist.centos.org/?release=6&arch=x86_64&repo=os error was
docker: 14: PYCURL ERROR 6 - "Couldn't resolve host 'mirrorlist.centos.org'"
==> docker: Killing the container: 200d89e0dce6770146b30d978a2040c5ec28c579de0f04bd812241bc2ff0033

if you do a 'docker ps' it comes empty, that container is not running.

but if you try to remove the actual image (tianon/centos:6.5) it complains that it cannot since it is used by container "200d89e0dce6770146b30d978a2040c5ec28c579de0f04bd812241bc2ff0033",

If seems that in case of an error Packer should not only kill the container, but automatically remove it as well, so a "docker rm " should be run as well in case of errors IMHO.

Otherwise the user may get left with a lot of containers defined (once every failed run) which then have to be removed manually one by one in case of any required cleanup.

[mitchellh]

Agreed. Thanks.

[jacek99]

Potentially a simple fix maybe to run the container with '--rm=true'. that may take care of it automatically.

 --rm=false: Automatically remove the container when it exits (incompatible with -d)

[mitchellh]

Fixed.

[polarlights]

@mitchellh
Is there some arguments that I can remain the running container. I want to attach to the container and find out what's wrong on earth. If it was killed, I can only get the error without any context. Thanks in advance.