Running Docker

Docker is installed on the DNP system. However, for security reasons, it must be configured to run in non-root mode.


First, run the install script, located in /usr/bin, to set up the daemon:

$ install

Next, it is necessary to specify an alternative path for docker to store data. The default directory for this is ~/.local/share/docker. However, as user directories are on a Network File System (NFS), this must be changed.

This is set in the file .config/docker/daemon.json, which for a new user should not exist. If it does exist, adjust the following procedure as needed. Otherwise, we can create a new directory in /scratch as follows:

Before Continuing

Be aware that /scratch only exists on the local system you’re using and it will therefore not be accessible from other workstations.

$ export DOCKER_DATA_ROOT=/scratch/$(whoami)/docker/data
$ mkdir -p $DOCKER_DATA_ROOT
$ printf "{\"data-root\": \"%s\"}\n" $DOCKER_DATA_ROOT > .config/docker/daemon.json

Please note, if for any reason, the docker was already running on your user account prior to adjusting the daemon configuration, you must restart the daemon for these changes to take effect.

$ systemctl --user stop docker


Docker provides a tutorial image that we can use to test the above configuration. First, start the docker daemon:

$ systemctl --user start docker

Now, docker should be ready for use. You can test this as follows:

$ docker run hello-world


If you encounter any errors throughout this process, please refer to the official documentation for running docker in non-root mode.