0 Fork 0

Files

T

bluebluesoda 769eeb0f2c feat(webssh): let the browser select and copy terminal text

- stop a mouse-down from stealing focus into the hidden input, which
  collapsed the selection a drag was building; focus comes back on a plain
  click, and after a real selection it is left where the copy shortcuts need it
- preserve a selection across repaints: note it as a row/character offset and
  put it back after a row is rewritten, so output no longer wipes it, and hold
  a frame while a drag is in progress
- let Ctrl/Cmd+C copy a selection instead of collapsing it first; it still
  interrupts when nothing is selected
- make the mount non-focusable, tint the selection, and document the behaviour

2026-09-26 15:46:16 +00:00

3.8 KiB

Raw Blame History

Web SSH

A terminal in the browser: a shell inside the user's own container, opened from the Machine card (next to Start / Stop / Restart) in the user panel.

It is not an SSH client. The container runs on the panel host, so the panel talks to it through the Incus exec API over the daemon's unix socket, with a PTY. Nothing listens on the container side, there are no keys to hand out, and there is no extra network path to arrange.

Shape of it

Its own window. The button opens a separate browser window rather than a dialog, so it can be dragged to any size, moved to another screen or maximised. It remembers the size it was last dragged to and reopens that way.
Root shell. The shell runs as root inside the account's own container, which is the same access the user already has over SSH. The container is always taken from the session: a client cannot name a container it does not own.
One account, two shells. A third connection is offered the option to close the others instead of being refused, which is also how a slot held by a closed window is reclaimed.

Surviving a bad connection

The panel is often reached from far away, so the browser side is built to survive the link rather than to be torn down by it.

Liveness. The server pings every 20 seconds and treats 60 seconds of silence as gone. The browser answers pings from its network stack, so this works in a backgrounded tab too, and a connection that disappears without saying so is noticed in about a minute.
Reconnect. The page hears a small heartbeat the server sends alongside the protocol pings; hearing nothing for 45 seconds means the socket is dead even though it has not said so. It then reconnects with exponential backoff and jitter, up to eight attempts, after which a manual Reconnect is offered.
Resume. The shell outlives the socket: when the client goes away the PTY keeps running for 120 seconds and its output goes into a bounded buffer (256 KiB, with a notice if anything is dropped). A client that comes back with its session token resumes the same shell — a running build, an open editor and the shell's variables are all still there.
Redraw. A resumed terminal starts blank and is rebuilt from the buffered output, so a full-screen program is asked to repaint itself; if one does not, Ctrl+L forces it.
Token. The resume token lives in sessionStorage, so reloading the page comes back to the shell and closing the window lets it go.

Keys and the mouse

Typing works as it does in any terminal: arrows, Home/End, PageUp/PageDown, Insert/Delete, Tab, Escape and the function keys all send what a terminal sends, and the arrows follow the mode a full-screen program asks for.

A small bar above the terminal carries the few keys a browser keeps for itself (Ctrl+C, Ctrl+Z, Ctrl+D, Escape, Tab), so they are never out of reach.

Selecting text is left to the browser, so it works like text anywhere: drag across the terminal to select, double-click a word, and the selection survives output arriving underneath it — a repaint puts the highlight back. Ctrl+C (or Cmd+C) copies a selection, and interrupts the running command when there is none, which is the rule a desktop terminal follows; the right-click menu offers Copy too.

Pasting uses the platform's shortcuts — Cmd+V/Ctrl+V, Shift+Insert — and a block of several lines is handed to the shell exactly as the shell asked for it: a shell with bracketed paste enabled shows the text in its edit buffer first.

Turning it off

vps config set panel.web_ssh false

The panel restarts and the feature is off: the button is not rendered, and the terminal page, its script and the terminal connection all refuse. true (the default) turns it back on. A configuration written before this feature existed comes out enabled.

3.8 KiB Raw Blame History