useradd not in amazonlinux base image

Question

It seems that useradd is not in amazonlinux docker base image.

useradd will work when when my Dockerfile install openldap-devel, so RUN useradd my_user will work when I my image have the following:

FROM amazonlinux

RUN yum -y install python3 \
    gcc \
    python3-pip \
    python3-devel \
    openldap-devel

When my image is just build from

FROM amazonlinux

RUN yum -y install python3 \
    gcc \
    python3-pip \
    python3-devel 

The command RUN useradd my_user fails with the error message /bin/sh: useradd: command not found

How do I install useradd in an amazonlinux base image without having to install all openldap-devel

Answer 1

I managed to figure out what package useradd belongs by running the following command on an AmazonLinux EC2 machine:

$ yum whatprovides /usr/sbin/useradd

2:shadow-utils-4.1.5.1-24.amzn2.x86_64 : Utilities for managing accounts and shadow password files
Repo        : amzn2-core
Matched from:
Filename    : /usr/sbin/useradd

So changing my Dockerfile to the following made it work:

FROM amazonlinux

RUN yum -y install python3 \
    python3-pip \
    shadow-utils

Answer 2

you can use the shadow-utils package as demeter has pointed out.

In my case, installing shadow-utils took too long in order to create my docker image, because it installed many dependencies. So I'll give you 2 alternatives:

1 - Use docker USER command:

You can do this in your Dockerfile:

FROM amazoncorretto:11.0.14-al2
USER 1000

This will allow you to start the container with a non-root user. From here, you can see that you don't need the user to exist. The downside is that this user has no name and no $HOME. I think this would usually be ok, but if there's any software in the container that needs a $HOME folder, it could give some problems.

2 - Use an existing user:

In the container, if you run cat /etc/passwd you'll see a list of existing users. Usually you'll have the nobody user that has the least permissions. So in your Dockerfile you can do:

FROM amazoncorretto:11.0.14-al2
USER nobody

and you're good 🔥