How to install new packages into non-root Docker Container?

Question

I'm trying to extend a docker container for SOLR. I just want to install vim into it. But when I run the docker build it complains that I'm not root.

This is the DockerFile that I'm extending: https://github.com/makuk66/docker-solr/blob/master/5.3/Dockerfile

And my build file is this:

FROM makuk66/docker-solr MAINTAINER OCSCommerce Team <[email protected]> RUN apt-get update RUN apt-get --assume-yes install vim COPY home/ocscommerce /etc/solr/home 

Then it outputs this:

192.168.99.100 localhost:solr$ docker build -t ocscommerce/solr . Sending build context to Docker daemon 39.66 MB Step 0 : FROM makuk66/docker-solr  ---> 92be2fe79f15 Step 1 : MAINTAINER OCSCommerce Team <[email protected]>  ---> Using cache  ---> a3ac70e40324 Step 2 : RUN apt-get update  ---> Running in c865716a2694 E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied) E: Unable to lock directory /var/lib/apt/lists/ E: Could not open lock file /var/lib/dpkg/lock - open (13: Permission denied) E: Unable to lock the administration directory (/var/lib/dpkg/), are you root? 

Is there any way to install a package into this container? Or would I need to copy the original build file from makuk66?

Answer 1

Switch to the root user, then switch back to the original solr user:

USER root  install/updates  USER solr 

Answer 2

Similar suggestion to the previous answer https://stackoverflow.com/a/37615312/2200690, open an interactive shell as the root user and then install your packages using apt-get.

docker exec --user="root" -it <container_name> /bin/bash 

install the package

apt-get install package