Docker Container cleanup on Elastic Beanstalk

Sometimes you may notice that old containers are not cleaned up from Beanstalk environment. This may be due to your container still running as a ghost on the background. One way to find out about this is to quickly look into your /var/lib/docker/vfs/dir directory whether it has too many folders.

Next, find out what container processes you have going on. [root@ip dir]# docker ps -a

You might see something like this:

    CONTAINER ID        IMAGE                              COMMAND             CREATED             STATUS              PORTS               NAMES
    1611e5ebe2c0        aws_beanstalk/staging-app:latest   "supervisord -n"    About an hour ago                                           boring_galileo
    e59d0dd8bba1        aws_beanstalk/staging-app:latest   "supervisord -n"    About an hour ago                                           desperate_yalow
    3844d0e18c47        aws_beanstalk/staging-app:latest   "supervisord -n"    2 hours ago         Up 8 minutes        80/tcp              pensive_jang

Ideally, we want to “forcibly remove” all images (and hence the folders from /var/lib/docker/vfs/dir directory) that are not in use anymore. Just run the following to test whether it works:

    docker rmi -f `docker images -aq`

You might run into trouble where docker says that all those images already have a container that is running them. This means those container are orphaned but not killed as we thought them to be. Let’s remove the shared volumes if any, for each one of them.

    docker rm -fv `docker ps -aq` 

This will

• kill the container
• unlink the volumes

You should see a lot more space now on your beanstalk instance.

    [root@ip dir]# df -h
    Filesystem      Size  Used Avail Use% Mounted on
    /dev/xvda1      7.8G  1.8G  5.9G  24% /
    devtmpfs        490M   96K  490M   1% /dev
    tmpfs           499M     0  499M   0% /dev/shm

Last Resort

If you feel that all this is not working, then you can try one of the scripts provided by docker itself at GitHub

It will delete the folders under /var/lib/docker and try to do it responsibly.