How to add users to Docker container?

Question

I have a docker container with some processes (uwsgi and celery) running inside. I want to create a celery user and a uwsgi user for these processes as well as a worker grou

Answer 1

Ubuntu

Try the following lines in Dockerfile:

RUN useradd -rm -d /home/ubuntu -s /bin/bash -g root -G sudo -u 1001 ubuntu
USER ubuntu
WORKDIR /home/ubuntu

useradd options (see: man useradd):

• -r, --system Create a system account. ^{see: Implications creating system accounts}
• -m, --create-home Create the user's home directory.
• -d, --home-dir HOME_DIR Home directory of the new account.
• -s, --shell SHELL Login shell of the new account.
• -g, --gid GROUP Name or ID of the primary group.
• -G, --groups GROUPS List of supplementary groups.
• -u, --uid UID Specify user ID. ^{see: Understanding how uid and gid work in Docker containers}
• -p, --password PASSWORD Encrypted password of the new account (e.g. ubuntu).

Setting default user's password

To set the user password, add -p "$(openssl passwd -1 ubuntu)" to useradd command.

Alternatively add the following lines to your Dockerfile:

SHELL ["/bin/bash", "-o", "pipefail", "-c"]
RUN echo 'ubuntu:ubuntu' | chpasswd

The first shell instruction is to make sure that -o pipefail option is enabled before RUN with a pipe in it. Read more: Hadolint: Linting your Dockerfile.