Linux users

System users on the VPS with a private home, optional sudo, forced password change and deletion with confirmation.

Category: Servers and infrastructure
Status: Available
Requirements: A running company VPS; To list and view: access to the VPS; To create, edit or delete: being a company admin
MCP tools (Read only): listar_usuarios_vps, ver_usuario_vps
MCP tools (Write or modify): crear_usuario_vps, editar_usuario_vps
MCP tools (Destructive): eliminar_usuario_vps

Markdown

What can you do with it?

List the users that can log in to the VPS and which ones have sudo.
Create a user with a password, a private home and, if requested, sudo.
Force a password change on first login (on by default).
Change the password or grant and remove sudo.
Delete a user, with or without their home folder.

When should you use it?

Giving someone SSH or terminal access without sharing root.
A dedicated user to run an application.
Removing access for someone who left the team.

How does it work in ArduMaker?

Creation

The name is validated: it starts with a lowercase letter or _, followed by lowercase letters, digits, _ or -, up to 32 characters. The password is required.
If the user does not exist, it is created with useradd -m -s /bin/bash, the password is set and, with force_password_change, it is marked as expired (chage -d 0). A user that already existed is not touched.
Its home /home/<usuario> is left with 700 permissions and any missing startup files from /etc/skel.
With sudo=true it is added to the sudo group.

Listing

Only “human” users appear: UID 1000 or higher, with a login shell and an enabled password, plus root. System users (www-data, postgres…) are not listed.

Deletion

root can never be deleted.
An agent must send confirmacion with the exact username: the guard forces it to read what is about to be destroyed.
By default the home folder is deleted too (remove_home=true); with false it is kept.
Processes running as that user keep going until they end: deleting the account does not kill them.
The deleted username is written to the VPS activity log.

What actually changes?

/etc/passwd, /etc/shadow and the system groups (sudo).
/home/<usuario> with 700 permissions, owned by the user.
The user list ArduMaker keeps for the VPS is updated on create and on list.
An entry in the VPS activity log for each operation.

Logging in with the user

Creating the user does not open SSH. To log in from outside you need a port forward to port 22, ideally with an expiry (see Firewall and ports):

ssh -p <host_port> usuario@<dnsip>

With force_password_change=true, on first login the system asks for the current password and a new one.

Diagram

Request: username, password, sudo
Validation: valid name, company admin
VPS agent: useradd → chpasswd → chage → usermod
Result: user with a 700 home and optional sudo

Creating a user

Expected result

listar_usuarios_vps returns users and sudo_users (always including root).
ver_usuario_vps returns the user's line in /etc/passwd.
crear_usuario_vps on a user that already exists returns that user with ya_existia: true instead of failing.

id usuario
sudo -l -U usuario

Errors and troubleshooting

Answer	Cause	What to do
400 `Invalid username`	Uppercase, spaces or disallowed characters	Use the valid format
404 `User '<usuario>' not found`	That user does not exist	List first
403 when deleting `root`	`root` is protected	—
428 without `confirmacion`	An agent did not send the exact name	Resend the same call with `confirmacion` equal to the username
403	Creating, editing or deleting requires a company admin	Ask an admin

Creating is safe to repeat (it returns the existing one with ya_existia), but in that case the password is not changed. A userdel or deluser through ejecutar_comando_vps is always rejected, with no way to confirm it: the intended path is eliminar_usuario_vps.

MCP access

Yes, in the /mcp and /mcp/vps profiles.

Tool	Type	Notes
`listar_usuarios_vps`, `ver_usuario_vps`	Read	—
`crear_usuario_vps`	Write	Admin; idempotent by name
`editar_usuario_vps`	Write	Admin; `password` and/or `sudo`
`eliminar_usuario_vps`	Destructive, irreversible	Admin; `confirmacion` = exact name

Reference at /mcp/docs and examples at /mcp/vps.