If you are using a Dockerfile, try: ENTRYPOINT [“tail”, “-f”, “/dev/null”] (Obviously this is for dev purposes only, you shouldn’t need to keep a container alive unless it’s running a process eg. nginx…)
In some cases (like in my case) you may be trying to delete an image by specifying the image id that has multiple tags that you don’t realize exist, some of which may be used by other images. In which case, you may not want to remove the image. If you have a case of … Read more
To run multiple commands in docker, use /bin/bash -c and semicolon ; docker run image_name /bin/bash -c “cd /path/to/somewhere; python a.py” In case we need command2 (python) will be executed if and only if command1 (cd) returned zero (no error) exit status, use && instead of ; docker run image_name /bin/bash -c “cd /path/to/somewhere && … Read more
The centos dockerfile has a default command bash. That means, when run in background (-d), the shell exits immediately. Update 2017 More recent versions of docker authorize to run a container both in detached mode and in foreground mode (-t, -i or -it) In that case, you don’t need any additional command and this is … Read more
The specific way to run it depends on whether you gave the image a tag/name or not. $ docker images REPOSITORY TAG ID CREATED SIZE ubuntu 12.04 8dbd9e392a96 4 months ago 131.5 MB (virtual 131.5 MB) With a name (let’s use Ubuntu): $ docker run -i -t ubuntu:12.04 /bin/bash Without a name, just using the … Read more
(original answer see below) Update Sept. 2016: Docker 1.13: PR 26108 and commit 86de7c0 introduce a few new commands to help facilitate visualizing how much space the docker daemon data is taking on disk and allowing for easily cleaning up “unneeded” excess. docker system prune will delete ALL dangling data (i.e. In order: containers stopped, … Read more
The contents of the /var/lib/docker directory vary depending on the driver Docker is using for storage. By default this will be aufs but can fall back to overlay, overlay2, btrfs, devicemapper or zfs depending on your kernel support. In most places this will be aufs but the RedHats went with devicemapper. You can manually set … Read more
An instance of an image is called a container. You have an image, which is a set of layers as you describe. If you start this image, you have a running container of this image. You can have many running containers of the same image. You can see all your images with docker images whereas … Read more