Ubuntu is not in the sudoers file. Docker

Introduction

When using Docker on Ubuntu, it is common to encounter the error message "ubuntu is not in the sudoers file. This incident will be reported." This error occurs when the user 'ubuntu' is not included in the sudoers file, which prevents the user from running commands with administrative privileges using 'sudo'.

In this article, we will explore the reasons behind this error message and provide solutions to resolve it.

Understanding sudoers file

The sudoers file, located at '/etc/sudoers', determines which users are allowed to run commands with administrative privileges using 'sudo'. By default, the sudoers file includes the 'root' user and members of the 'sudo' group. This allows them to execute commands with elevated privileges.

Possible Causes

  1. Incorrect User Configuration: The user 'ubuntu' might not be a member of the 'sudo' group or have sudo privileges configured correctly.
  2. Docker Image Configuration: The Docker image being used may not have the necessary configurations to allow the 'ubuntu' user to run commands with 'sudo'.

Solution

Solution 1: Add 'ubuntu' user to the 'sudo' group

To resolve the issue, we can add the 'ubuntu' user to the 'sudo' group, which will grant them sudo privileges.

  1. Log in to the Ubuntu system using another user with administrative privileges.
  2. Open the terminal and run the following command to add the 'ubuntu' user to the 'sudo' group:
sudo usermod -aG sudo ubuntu
  1. Verify the changes by logging out of the system and logging back in as the 'ubuntu' user. Now, the 'ubuntu' user should be able to use 'sudo' without any error.

Solution 2: Modify Docker Image Configuration

If the issue persists even after adding the 'ubuntu' user to the 'sudo' group, it might be necessary to modify the Docker image configuration.

  1. Access the Dockerfile used to build the Docker image.
  2. Locate the line that creates the 'ubuntu' user inside the Dockerfile, which looks something like this:
RUN useradd -m -s /bin/bash ubuntu
  1. Add the following line after the user creation to grant 'sudo' privileges to the 'ubuntu' user:
RUN usermod -aG sudo ubuntu
  1. Rebuild the Docker image using the modified Dockerfile and try running the container again. The 'ubuntu' user within the container should now have the necessary sudo privileges.

Conclusion

Encountering the error message "ubuntu is not in the sudoers file" while using Docker on Ubuntu can be resolved by adding the 'ubuntu' user to the 'sudo' group or modifying the Docker image configuration. It is crucial to ensure that the user has the necessary sudo privileges to perform administrative tasks.

By following the solutions provided above, you should be able to fix the issue and continue using Docker with the 'ubuntu' user without any sudo-related errors.