How to Completely Disable ‘Sudo’ Password Prompts for a Specific User in Ubuntu

In Ubuntu Linux, the sudo command is the primary mechanism for executing commands with elevated root privileges. By default, whenever a standard user in the sudo group attempts to run a command prefixed with sudo, the operating system pauses the execution and prompts the user to enter their personal password to verify their identity.

While this is a crucial security barrier for interactive desktop users, it completely breaks automated shell scripts, continuous integration (CI/CD) pipelines, and headless server deployments. If you have written a bash script that needs to restart a systemd service or modify a system configuration file, the script will permanently hang the moment it encounters the password prompt. To allow automated background scripts to execute root-level commands without human intervention, you must completely disable the password requirement for the specific user account running the script.

Disabling the Sudo Password via Visudo

You must modify the system’s sudoers configuration file. Never edit this file directly with nano or vim; you must always use the visudo command, which syntax-checks the file before saving to prevent you from accidentally locking yourself out of root access.

1. Open a Terminal session (or connect to your server via SSH).
2. Run the following command to open the sudoers file safely:
   sudo visudo
3. Use your arrow keys to scroll to the absolute bottom of the file.
4. Paste the following line exactly as written, replacing username with the actual username of the account you want to grant passwordless access to (e.g., deploybot or jenkins):
   username ALL=(ALL) NOPASSWD: ALL
5. Save the file (if visudo is using nano, press Ctrl + O, then Enter) and exit the text editor (Ctrl + X).

Verifying the Change

The new sudo policy takes effect immediately without requiring a reboot or a service restart.

1. Switch to the user account you just modified (or log out and log back in as that user).
2. Run a harmless command that typically requires root privileges, such as:
   sudo apt-get update
3. The command will instantly execute and begin fetching repository data without ever prompting you for a password.

Extreme Warning: You have effectively given this specific user account god-level access to the entire server without any secondary verification. If a malicious actor compromises this user account (e.g., by exploiting a vulnerability in a web application running under this user), they instantly own the entire machine. Only use NOPASSWD for dedicated, heavily restricted automation accounts, and never for your primary daily-driver login.