How to Reset the Password or SSH Key on a Linux based VM in Quake AI

Quake AI does not have special access to reset a user's password or SSH key. However, since a VM behaves like a normal server, standard processes can be used to perform a password reset if such a process exists for your operating system.

This guide presents an example using Ubuntu 24.04, but the same process applies to most Linux distributions, and also for similar operating systems such as BSD-based derivatives.

Before you begin#

Steps to reset a password or SSH key#

1. Log in to the console#

Open the console for your VM from the Quake AI dashboard.

2. Prepare your console window#

Resize your browser window so you can access the "Send CtrlAltDel" button in the top-right corner.

Click inside the black console window so that your keystrokes register inside the VM instead of your local computer.

3. Reboot and enter GRUB#

Click "Send CtrlAltDel". Immediately click inside the console window and press ESC several times.

Because the VM reboots fast, act during the boot window. You should see the following GNU GRUB window. If instead the system continues to boot, allow the VM to boot fully, then repeat this step until you see the GRUB prompt after pressing the ESC key several times.

#

4. Edit the boot entry#

If you see the GNU GRUB boot menu, use the arrow keys to select the default boot entry (Ubuntu on the standard images).

Press e to edit it.

5. Add single-user mode#

Scroll to the line that begins with linux.

At the end of the line, add the word single

6. Boot into maintenance mode#

Press Ctrl+X to boot with the modified entry.

The system begins to boot, and you should eventually see:

Press Enter for Maintenance

Press Enter, and you get a root shell prompt.

7. Reset a password#

At the prompt, type:

passwd ubuntu

This resets the password for the ubuntu user.

You may also reset the password for root or any other user as needed.

8. Exit maintenance mode#

Type:

exit

Your system should now continue booting to the normal login console.

9. Access with password or SSH#

• If you normally use password-based access (not recommended), you can now log in with the new password using your normal processes.
• If you are using SSH key-based access (preferred), you will need to continue passed this step to also update your SSH key configuration.

10. Reset SSH key access#

SSH keys are stored in:

~/.ssh/authorized_keys

To update them:

1. First, log in with your new password via SSH.
2. Edit the authorized_keys file to add your new SSH key.

⚠️ Since the web console does not allow cut-and-paste, this step is easiest to complete over an SSH session.

If your system is not configured to allow password login over SSH, you will need to temporarily enable it. For the Quake AI Ubuntu image, follow the instructions below. For other distributions the file location, etc. may be slightly different.:

1. Edit:

   bash

   /etc/ssh/sshd_config.d/60-cloudimg-settings.conf

   Set:

   bash

   PasswordAuthentication yes

2. Restart SSH:

   bash

   sudo systemctl restart ssh

11. Revert temporary changes#

After you confirm SSH key access is restored:

1. Revert the SSH configuration change (PasswordAuthentication no).

2. Optionally remove the password you set earlier by running:

   bash

   sudo passwd -d ubuntu

Troubleshooting#

GRUB does not appear#

• Confirm you completed the GRUB timeout prerequisite in Before you begin if this is your first recovery attempt on the Quake AI Ubuntu cloud image.
• If the console does not capture your key presses, click inside the console window immediately after you select Send CtrlAltDel.

System boots without maintenance prompt#

• Double-check that you edited the correct linux line in GRUB.
• Ensure the word single was added at the end of the line.

SSH keys get overwritten after reboot#

The Quake AI Ubuntu cloud image's cloud-init configuration (/etc/cloud/cloud.cfg) does not overwrite ~/.ssh/authorized_keys on reboot. If you observe this behavior on a non-Quake AI image, consult that image's cloud-init documentation (/etc/cloud/cloud.cfg and /etc/cloud/cloud.cfg.d/) and the upstream cloud-init users / ssh_authorized_keys reference. Do not edit /etc/cloud/cloud.cfg directly on a vendor-managed image; use a drop-in under /etc/cloud/cloud.cfg.d/.

Cannot edit files in console#

• The web console does not allow copy-paste. If you need to add long SSH keys, use password login temporarily, then update your key via an SSH session.

Summary#

By following these steps, you can recover access to your Quake AI VM when password or SSH key access is lost. The process leverages standard Linux recovery workflows, meaning it works the same way as it would on a physical linux server.