Problem: Adding Users to Docker Containers Non-Interactively
Adding users to Docker containers often needs interactive prompts. This can be inconvenient for automated processes or scripted deployments. It creates a challenge when trying to improve container management and user provisioning without manual input.
The Solution: Non-Interactive User Creation
Using useradd for Automated User Addition
The useradd command is a non-interactive option to adduser for creating users in Docker containers. This command lets you add users without manual input during the build process.
The basic syntax for useradd is:
useradd [options] usernameCommon options include:
-m: Create the user's home directory-s: Specify the user's login shell-u: Set a specific user ID-g: Assign the user to a primary group
Tip: Secure User Creation
When creating users with useradd, consider using the -p option to set an encrypted password. This improves security by avoiding the use of default or empty passwords. For example:
useradd -m -s /bin/bash -p $(openssl passwd -1 "secure_password") usernameImplementing the Solution in Dockerfile
To add users non-interactively in your Dockerfile, you can use the useradd command with options. Here's an example of how to add users in your Dockerfile:
RUN useradd -ms /bin/bash uwsgi
RUN useradd -ms /bin/bash celeryThis creates two users, 'uwsgi' and 'celery', each with their own home directory and bash as their default shell.
To create a shared group for these users, you can use the groupadd command:
RUN groupadd worker
RUN usermod -aG worker uwsgi
RUN usermod -aG worker celeryThese commands create a 'worker' group and add both 'uwsgi' and 'celery' users to it.
