Terminal and SSH

User

The browser terminal

The fastest way in. Open the job’s detail panel and choose Terminal in the header, or use the Terminal toggle at the bottom of the navigation to open the drawer.

You are root inside your container. The terminal is only available while the job is running - on any other state the action is disabled.

The browser terminal dies with the page

Close the tab and the shell goes with it, taking any foreground process with it. For anything long-running, start it under tmux or screen, or run it with nohup. This is the single most common way people lose eight hours of training.

SSH from your own machine

Worth setting up if you want your editor, port forwarding, or rsync.

1. Expose port 22 when you create the job. Ports cannot be added afterwards - only opened and closed. If you forgot, clone the job and add it.

2. Run an SSH server inside the container. Most images do not have one. From the browser terminal:

   apt-get update && apt-get install -y openssh-server
   mkdir -p /run/sshd
   # Key-based auth only; a password on a public port is a bad trade.
   mkdir -p ~/.ssh && chmod 700 ~/.ssh
   echo 'ssh-ed25519 AAAA... you@example.com' >> ~/.ssh/authorized_keys
   chmod 600 ~/.ssh/authorized_keys
   /usr/sbin/sshd -D &

3. Open the port. In the detail panel’s Proxy view, open port 22 as public or private.

4. Connect to the address and port shown in the proxy table:

   ssh -p <proxy-port> root@<proxy-host>

Never open a password-authenticated SSH port publicly

A public proxy is reachable from the internet. Use a key, or restrict the port with an IP filter, or both. Prefer a private port if your relay supports it.

Keeping work alive

tmux

tmux new -s work
# detach with ctrl-b then d; reattach later with:
tmux attach -t work

The session survives the browser tab closing, and survives an SSH disconnect. It does not survive the job’s runtime expiring.

nohup

nohup python train.py > /homecatalog/train.log 2>&1 &

Note the log going to a mounted path, so it is still there afterwards.

Start it automatically

Set the job’s command to start your work directly. The job then needs no shell at all, and on a non-interactive queue this is the only way.

What does not survive

Nothing outside a mounted folder. Not your shell history, not your installed packages, not your checkpoints. If a container is precious, the answer is to bake it into an image, not to keep the job alive.