= DockerContainerUser =
 * By default docker runs with the user in the container as root 0:0 having full access to stuff in the container, including mounted directories.

== Specify specific user ==
 * Why ?
   * When using docker to just build local code, mounting it into a nodejs / java / python container, we want the artifacts left in the mounted directory to be owned by the local users
 * How ?
   * -u ubuntu:ubuntu   docker flag to set user.
   * more generic  {{{ --user $(id -u ${USER}):$(id -g ${USER})  }}}
   * e.g {{{
docker container run --rm \
    -v ${PWD}:/var/www \
    -w /var/www \
    -u $(id -u ${USER}):$(id -g ${USER}) \
    mycontainer/python:7.2 composer 
}}}

== Using user in Dockerfile ==
 * When building docker containers a default user can be set, normally this will be 1000:1000.
 * This is normally done to the end of the docker definition to allow root to update packages before switching to user.