How to Grant Sudo Privileges to Regular Users on Linux

Background

On Linux systems it is common to avoid logging in as the root user. When a command requires root privileges, the sudo command is used to temporarily elevate the current user's permissions.

If a regular user is not listed in the sudoers configuration, attempting sudo will produce an error such as "user is not in the sudoers file".

Sudo Permission Configuration

The full name of sudo is super user do, meaning the command runs with root privileges. Whether a user can run sudo is determined by entries in the /etc/sudoers file. /etc/sudoers is a plain‑text file with a strict syntax; it should be edited with the visudo command rather than directly with vim or vi. Only the root user can execute visudo.

Switch to the root account and run: # visudo This opens the /etc/sudoers file for editing. A typical bottom section looks like:

# User privilege specification
root    ALL=(ALL:ALL) ALL

# Members of the admin group may gain root privileges
%admin  ALL=(ALL) ALL

# Allow members of group sudo to execute any command
%sudo   ALL=(ALL:ALL) ALL

# See sudoers(5) for more information on "#include" directives:
#includedir /etc/sudoers.d
ubuntu  ALL=(ALL:ALL) NOPASSWD: ALL

Explanation of each column:

First column: username (e.g., root, ubuntu).

Second column (left of =): ALL means the user may log in from any host.

Third column (right of =): ALL indicates the user may run any command as root.

The NOPASSWD keyword (shown for the ubuntu user) allows sudo without prompting for a password.

If a user receives the "not in sudoers" warning, they simply lack an entry in this file.

To grant sudo rights to a new user (e.g., test_user) with the default password prompt, add the following line to /etc/sudoers:

test_user  ALL=(ALL:ALL)  ALL   # test_user must provide password for sudo

For password‑less sudo, use:

test_user  ALL=(ALL:ALL)  NOPASSWD:ALL   # no password required for sudo

After editing, exit and save with :wq. Switch to test_user and prepend sudo to commands that need root privileges, for example:

[test_user@host ~]$ sudo docker ps -a
CONTAINER ID   IMAGE       COMMAND   CREATED   STATUS   PORTS   NAMES
903734808a1e   hello-world "/hello"   About an hour ago   Exited (0) About an hour ago   happy_jennings

The command now executes successfully, confirming that sudo is properly configured for the user.

Conclusion

For temporary privilege elevation, simply add the appropriate line to /etc/sudoers using visudo. Editing the file directly with vi or vim is discouraged because visudo validates syntax and prevents configuration errors.