fix: improve userctl

docs/admin.md

@@ -7,6 +7,9 @@ Please do **not** use the standard Linux commands (e.g., `useradd`, `adduser`, .
 The script is interactive and allows to add, remove, and edit users.
 Please run `sudo userctl --help` for more information.
 
+Users on this server are identified by their university email address.
+Thus, `userctl` expects the full email address as argument.
+
 ## Process Management
 
 Some users may forget to stop their processes or block all GPUs at once.

modules/userctl.py

@@ -25,7 +25,9 @@ def run_cmd(cmd: Sequence[str], **kwargs) -> str:
 
 def check_email(user: str):
     if not user.endswith("@uni-trier.de"):
-        raise typer.BadParameter("Only university mail addresses are allowed")
+        raise typer.BadParameter(
+            "Please provide the university email address, the script determines the username automatically"
+        )
 
     return user.split("@")[0]