Commit Graph
3 Commits
Author SHA1 Message Date
irisandClaude Opus 5 362d436d4f Let sessions outlive the backend, and never resume one twice
Three `claude` processes ended up running against this checkout on
2026-08-29, and the account hit its session limit. One cause, several
ways in.

An agent imported the Claude Code session it was *itself* running in.
That is an ordinary import, and importing runs `--resume` -- so a second
CLI attached to a file the first was still writing. The whole 65 MB
conversation, 154 embedded screenshots included, was re-appended to the
transcript under a new prompt id; both copies then read each other's
writes as work done elsewhere, and the adopted one was billed for
re-reading all of it. Meanwhile `shutdown_all` asked each session to stop
and the process exited immediately, so the SIGKILL timer died with the
runtime, the stop was unreliable, and whatever survived was orphaned with
nothing written down to find it by.

The processes leaked either way. So leak them on purpose, and be able to
pick them back up.

A session's process now outlives the backend and is adopted again on the
way up, which is worth having for its own sake: restarting the server no
longer ends a turn somebody is waiting on. Its stdio lives in the session
directory -- a fifo opened read-write so the process is its own last
writer and never reads EOF, plus stdout/stderr logs read from a byte
offset. `session::process` records the pid *and* the kernel's start time
for it, because a pid alone is reused and adopting a stranger's would mean
never resuming the real conversation.

That makes the fix structural rather than a check: everything goes through
`ClaudeDriver::launch`, which adopts if it can and starts if it cannot,
and `--resume` is reachable only on the second path. `Driver` gains two
ways out where it had one -- `detach` (coming back) and `stop` (the
session is being deleted, so the process must not survive).

Importing a session that is open is now refused outright. Claude Code
keeps `~/.claude/sessions/<pid>.json` for every live session, so this is a
measurement rather than a guess; it reports no/yes/unknown, because a
machine that keeps no such record cannot answer and "could not check" is
not "nobody is using it". `SessionStatus` gains `Unknown` for the same
reason.

Also here, found on the way:

- A reconnecting phone was sent the entire backlog. Opening a session was
  bounded to a page but reconnecting was not, so a long disconnect
  delivered thousands of events one frame at a time. Past `CATCH_UP_LIMIT`
  the stream sends a `reset` frame and the newest window, and the client
  rebuilds from it as it does on open -- without the reset the window is
  spliced onto rows no longer adjacent to it.
- A session's status was assumed idle at launch. Read from the transcript
  instead, so a restart stops claiming an exited session is waiting for
  you.
- `llama-server`'s stdout was piped and never drained, so a chatty one
  blocked on a full pipe buffer mid-load. It goes to a log now.
- A turn that exited or errored never emitted `Idle`, so the queue stayed
  "running" for good: every later message was held forever and, since a
  message is only recorded when taken, vanished with nothing on screen.
- Two doc comments had drifted onto the wrong functions.

Verified by killing the server mid-turn: the process survived, finished
its turn unattended (12.8 KB of output nothing was reading), and the
restarted server adopted it -- one process, all 700 lines in the
transcript, no hole, and it still took a new message afterwards. Deleting
a session stops its process; a 266-event backlog resets while a 16-event
one streams. 46 tests, clippy and rustfmt clean, app compiles and lints.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01VETa8afmpWaYezLCqJhDB8
2026-08-29 04:47:43 -04:00
irisandClaude Opus 5 3c144f8070 A screen for the machines, and failures a phone can act on
The other half of making setups editable: add, rename, rediscover and
remove, with a Test that tries a machine before anything is saved.

The screen cannot name a program, which is the point rather than an
omission -- providers are what the server found when it asked, so this app
has no way to introduce something to run. The dialog says so, because
"what it can run is discovered, not typed" is the answer to the question a
person will otherwise ask when they look for a command field.

Two things running it changed. The card showed "this machine / this
machine", because the seeded setup is *called* that and my fallback line
for a local setup said the same -- the line now says something the name
cannot also be. And the header row absorbed a fifth action without
complaint, which is the earlier title-and-actions split paying off exactly
as its comment predicted.

**Host key verification is the failure that would have made this look
broken.** Every machine fails it the first time, because its key is not in
known_hosts yet, and ssh's own words -- "Host key verification failed." --
are written for somebody at a terminal on the backend, which is exactly who
is not reading a phone. It now says what to do: ssh to it once from the
backend and try again. Permission denied gets the same treatment.

Deliberately *not* fixed by relaxing StrictHostKeyChecking. Accepting a new
key is a decision somebody should make with the key in front of them, not
something this app does quietly on their behalf while adding a machine.

Verified on the emulator against a running server: the seeded setup renders
with what was discovered on it, the add dialog explains itself, and Test
against an untrusted machine produces the full explanation rather than
ssh's four words.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw
2026-08-28 13:17:08 -04:00
irisandClaude Opus 5 19e3531c5d Add, rename and remove machines from the phone -- without letting it name commands
The gap PLAN.md recorded: setups were readable but only hand-editable, so
adding a machine meant a shell on the backend.

**The design decision, made with Bryan, is that the phone never composes a
command.** A setup carries providers, and a provider carries something to
run -- so a route that accepted a command from the request body would make
the enrolled token arbitrary code execution on every machine a setup names,
and the transport already reaches those over ssh. Instead the phone sends
connection details, and the server asks the machine itself what it has:
one `command -v` round trip per setup, matched against a table of the
drivers this server knows. The phone's authority is "add this machine",
never "run this".

Worth recording that this was a narrower change than it first appeared: the
token could already run anything on the backend, because the spawn screen
offers `bypassPermissions` with a free-text working directory. Discovery
does not close that door. What it does is keep the *list of what can run*
out of the phone's reach, and make adding a machine a thing you cannot get
wrong by typing.

It is also simply better to use. Nobody wants to type an absolute path on a
phone keyboard, and a machine whose binaries have moved answers correctly
on the next probe. The cost is that a program somewhere unusual is
invisible -- `command -v` follows PATH under a non-interactive ssh session,
which is not the PATH a person sees when they log in. That is the trade,
and the escape hatch is editing config.ron on the backend, which is exactly
the authority the phone is not being given.

Setups now have an **id separate from their label**, so renaming a machine
does not orphan the sessions that name it; a session stores the id, and
every row resolves the current label when it is built. `POST /setups/probe`
tries a machine without saving anything, so a wrong address or an
unauthorised key is caught while the form that caused it is still on
screen. Deleting is refused while sessions still run there, and says which
ones rather than cascading.

Every mutation goes through one `update`: clone, apply, save, then commit,
so a failed write leaves the previous state intact and reports why.

Verified against a running server, including a real ssh machine (this VM,
via a throwaway loopback key since removed): probing here found echo and
claude-cli; probing over ssh found claude-cli and correctly no echo, which
runs in-process and exists only where this server does; an unreachable
machine came back with ssh's own words ("connect to host ... Connection
timed out"); adding derived the id `loopback-vm` from "loopback vm";
renaming kept the id; deleting was refused while a session used it, naming
it, and succeeded once nothing did.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_017xn8nHw1tw1R6PtiY1eEtw
2026-08-28 13:08:44 -04:00