Configuring a Docker image

Question

I'm trying to build a Dockerfile. But after executing I get this error:

Sending build context to Docker daemon  31.08MB
Step 1/5 : FROM davidrazd/discord-node-10
 ---> 0ad384ff6003
Step 2/5 : RUN apt-get update
 ---> Running in 9fb4313d8011
Reading package lists...
W: chmod 0700 of directory /var/lib/apt/lists/partial failed - SetupAPTPartialDirectory (1: Operation not permitted)
E: Could not open lock file /var/lib/apt/lists/lock - open (13: Permission denied)
E: Unable to lock directory /var/lib/apt/lists/
The command '/bin/sh -c apt-get update' returned a non-zero code: 100

I also tried to put sudo in the dockerfile to make sure I have full access as root.

Dockerfile:

# Start writing your Dockerfile easily
FROM davidrazd/discord-node-10

RUN sudo apt-get update
RUN sudo apt-get install -y python-pip
RUN sudo install --upgrade pip

Answer 1

The image you imported includes a user specification:

USER container

The apt-get update and apt-get install command require root access. Within a docker build, you get root access by running your container commands as root, rather than performing a sudo. Therefore, your dockerfile would look like:

# Start writing your Dockerfile easily
FROM davidrazd/discord-node-10
USER root
RUN apt-get update \
 && apt-get install -y python-pip \
 && install --upgrade pip
USER container

I'd recommend reading the following before getting much further into writing your Dockerfiles since there are other issues you'll want to resolve with the apt-get commands (chaining commands, removing input from config, not installing recommended packages, and cleaning up after the install commands): https://docs.docker.com/develop/develop-images/dockerfile_best-practices/