| 1 | //! Web surface for agent sessions: the session list and page, the websocket |
| 2 | //! that bridges a browser terminal to the container's tmux, and the vendored |
| 3 | //! terminal emulator assets. |
| 4 | //! |
| 5 | //! The wire format on the websocket is ours rather than wterm's built-in |
| 6 | //! transport, which is a raw byte pass-through with no control channel and so |
| 7 | //! no way to carry a resize: |
| 8 | //! |
| 9 | //! - **binary frames** are raw terminal bytes, in both directions; |
| 10 | //! - **text frames** are JSON control messages — `{"t":"resize",…}` from the |
| 11 | //! browser, `{"t":"exit",…}` back. |
| 12 | |
| 13 | use anvil_agent::StartError; |
| 14 | use anvil_core::{ |
| 15 | App, |
| 16 | User, |
| 17 | access, |
| 18 | agent::{ |
| 19 | self, |
| 20 | kind, |
| 21 | status, |
| 22 | }, |
| 23 | }; |
| 24 | use axum::{ |
| 25 | Router, |
| 26 | extract::{ |
| 27 | Path, |
| 28 | State, |
| 29 | ws::{ |
| 30 | Message, |
| 31 | WebSocket, |
| 32 | WebSocketUpgrade, |
| 33 | }, |
| 34 | }, |
| 35 | http::header, |
| 36 | response::{ |
| 37 | IntoResponse, |
| 38 | Redirect, |
| 39 | Response, |
| 40 | }, |
| 41 | routing::{ |
| 42 | get, |
| 43 | post, |
| 44 | }, |
| 45 | }; |
| 46 | use futures_util::{ |
| 47 | SinkExt, |
| 48 | StreamExt, |
| 49 | }; |
| 50 | use maud::{ |
| 51 | Markup, |
| 52 | PreEscaped, |
| 53 | html, |
| 54 | }; |
| 55 | use tokio::io::AsyncWriteExt; |
| 56 | |
| 57 | use crate::{ |
| 58 | auth::{ |
| 59 | Csrf, |
| 60 | CsrfForm, |
| 61 | CurrentUser, |
| 62 | verify_csrf, |
| 63 | }, |
| 64 | ui::{ |
| 65 | self, |
| 66 | forbidden, |
| 67 | layout, |
| 68 | not_found, |
| 69 | server_error, |
| 70 | }, |
| 71 | }; |
| 72 | |
| 73 | pub fn routes(router: Router<App>) -> Router<App> { |
| 74 | router |
| 75 | .route("/{owner}/{repo}/-/agent", get(list).post(create)) |
| 76 | .route("/{owner}/{repo}/-/agent/{id}", get(show)) |
| 77 | .route("/{owner}/{repo}/-/agent/{id}/stop", post(stop)) |
| 78 | .route("/{owner}/{repo}/-/agent/{id}/ws", get(socket)) |
| 79 | .route("/-/static/wterm/{*path}", get(wterm_asset)) |
| 80 | } |
| 81 | |
| 82 | // --- vendored terminal emulator -------------------------------------------- |
| 83 | |
| 84 | /// wterm (Apache-2.0), vendored as published ESM and embedded in the binary, |
| 85 | /// exactly as htmx is. No bundler is involved: the tree has a single bare |
| 86 | /// specifier (`@wterm/core`), which the page resolves with an import map. |
| 87 | /// |
| 88 | /// The built-in core's WASM is inlined as base64 inside `wasm-inline.js`, so |
| 89 | /// there is no separate binary to fetch and no `import.meta.url` resolution to |
| 90 | /// get wrong. |
| 91 | const WTERM_ASSETS: &[(&str, &str, &str)] = &[ |
| 92 | ( |
| 93 | "core/index.js", |
| 94 | include_str!("../assets/wterm/core/index.js"), |
| 95 | JS, |
| 96 | ), |
| 97 | ( |
| 98 | "core/terminal-core.js", |
| 99 | include_str!("../assets/wterm/core/terminal-core.js"), |
| 100 | JS, |
| 101 | ), |
| 102 | ( |
| 103 | "core/transport.js", |
| 104 | include_str!("../assets/wterm/core/transport.js"), |
| 105 | JS, |
| 106 | ), |
| 107 | ( |
| 108 | "core/wasm-bridge.js", |
| 109 | include_str!("../assets/wterm/core/wasm-bridge.js"), |
| 110 | JS, |
| 111 | ), |
| 112 | ( |
| 113 | "core/wasm-inline.js", |
| 114 | include_str!("../assets/wterm/core/wasm-inline.js"), |
| 115 | JS, |
| 116 | ), |
| 117 | ( |
| 118 | "dom/index.js", |
| 119 | include_str!("../assets/wterm/dom/index.js"), |
| 120 | JS, |
| 121 | ), |
| 122 | ( |
| 123 | "dom/debug.js", |
| 124 | include_str!("../assets/wterm/dom/debug.js"), |
| 125 | JS, |
| 126 | ), |
| 127 | ( |
| 128 | "dom/hyperlink.js", |
| 129 | include_str!("../assets/wterm/dom/hyperlink.js"), |
| 130 | JS, |
| 131 | ), |
| 132 | ( |
| 133 | "dom/input.js", |
| 134 | include_str!("../assets/wterm/dom/input.js"), |
| 135 | JS, |
| 136 | ), |
| 137 | ( |
| 138 | "dom/renderer.js", |
| 139 | include_str!("../assets/wterm/dom/renderer.js"), |
| 140 | JS, |
| 141 | ), |
| 142 | ( |
| 143 | "dom/wterm.js", |
| 144 | include_str!("../assets/wterm/dom/wterm.js"), |
| 145 | JS, |
| 146 | ), |
| 147 | ( |
| 148 | "terminal.css", |
| 149 | include_str!("../assets/wterm/terminal.css"), |
| 150 | CSS, |
| 151 | ), |
| 152 | ]; |
| 153 | |
| 154 | const JS: &str = "application/javascript; charset=utf-8"; |
| 155 | const CSS: &str = "text/css; charset=utf-8"; |
| 156 | |
| 157 | /// Serve one vendored wterm file. A `match` over embedded constants rather than |
| 158 | /// a route each, since it is a dozen files that only ever change together. |
| 159 | async fn wterm_asset(Path(path): Path<String>) -> Response { |
| 160 | let Some((_, body, content_type)) = WTERM_ASSETS.iter().find(|(name, _, _)| *name == path) |
| 161 | else { |
| 162 | return not_found("no such asset"); |
| 163 | }; |
| 164 | ( |
| 165 | [ |
| 166 | (header::CONTENT_TYPE, *content_type), |
| 167 | // Vendored at a fixed version and only replaced by a redeploy. |
| 168 | (header::CACHE_CONTROL, "public, max-age=31536000, immutable"), |
| 169 | ], |
| 170 | *body, |
| 171 | ) |
| 172 | .into_response() |
| 173 | } |
| 174 | |
| 175 | // --- pages ------------------------------------------------------------------ |
| 176 | |
| 177 | /// Resolve the repo and require write access: starting a session runs code |
| 178 | /// against the repository and (from M2) pushes to it, so it is an owner action, |
| 179 | /// not a reader one. |
| 180 | async fn resolve_writable( |
| 181 | app: &App, |
| 182 | viewer: Option<&User>, |
| 183 | owner: &str, |
| 184 | name: &str, |
| 185 | ) -> Result<anvil_core::Repository, Response> { |
| 186 | let (_, repo) = ui::resolve_repo(app, viewer, owner, name).await?; |
| 187 | if !access::can_write(&repo, viewer) { |
| 188 | return Err(forbidden()); |
| 189 | } |
| 190 | Ok(repo) |
| 191 | } |
| 192 | |
| 193 | /// `GET /{owner}/{repo}/-/agent` — this repository's sessions. |
| 194 | async fn list( |
| 195 | State(app): State<App>, |
| 196 | CurrentUser(user): CurrentUser, |
| 197 | Path((owner, name)): Path<(String, String)>, |
| 198 | ) -> Result<Markup, Response> { |
| 199 | let repo = resolve_writable(&app, user.as_ref(), &owner, &name).await?; |
| 200 | let sessions = agent::list_by_repo(&app.db, repo.id, 50) |
| 201 | .await |
| 202 | .map_err(server_error)?; |
| 203 | let enabled = app.config.agent.enabled; |
| 204 | let csrf = crate::auth::current_csrf(); |
| 205 | |
| 206 | Ok(layout( |
| 207 | &format!("{owner}/{name} · agent"), |
| 208 | user.as_ref(), |
| 209 | html! { |
| 210 | h1 { "Agent sessions" } |
| 211 | @if !enabled { |
| 212 | p.notice { |
| 213 | "Agent sessions are disabled. Set " |
| 214 | code { "agent.enabled" } |
| 215 | " in anvil.toml to turn them on." |
| 216 | } |
| 217 | } @else { |
| 218 | form method="post" action={"/" (owner) "/" (name) "/-/agent"} { |
| 219 | (ui::csrf_input(&csrf)) |
| 220 | label { |
| 221 | "Start from branch " |
| 222 | input type="text" name="base_ref" value="main" required; |
| 223 | } |
| 224 | label { |
| 225 | "Opening prompt (optional — leave empty to drive it yourself)" |
| 226 | textarea name="prompt" rows="3" {} |
| 227 | } |
| 228 | button type="submit" { "Start session" } |
| 229 | } |
| 230 | } |
| 231 | @if sessions.is_empty() { |
| 232 | p { "No sessions yet." } |
| 233 | } @else { |
| 234 | ul.sessions { |
| 235 | @for session in &sessions { |
| 236 | li { |
| 237 | a href={"/" (owner) "/" (name) "/-/agent/" (session.id)} { |
| 238 | "#" (session.id) |
| 239 | } |
| 240 | " " span.status { (session.status) } |
| 241 | " " span.muted { (session.base_ref) " @ " |
| 242 | (short_commit(&session.base_commit)) } |
| 243 | " " span.muted { (ui::fmt_relative(session.created_at)) } |
| 244 | } |
| 245 | } |
| 246 | } |
| 247 | } |
| 248 | }, |
| 249 | )) |
| 250 | } |
| 251 | |
| 252 | fn short_commit(commit: &str) -> &str { |
| 253 | &commit[..commit.len().min(12)] |
| 254 | } |
| 255 | |
| 256 | /// `POST /{owner}/{repo}/-/agent` — start a session. |
| 257 | async fn create( |
| 258 | State(app): State<App>, |
| 259 | CurrentUser(user): CurrentUser, |
| 260 | csrf: Csrf, |
| 261 | Path((owner, name)): Path<(String, String)>, |
| 262 | axum::Form(form): axum::Form<CreateForm>, |
| 263 | ) -> Result<Response, Response> { |
| 264 | verify_csrf(&csrf, &form.csrf)?; |
| 265 | let repo = resolve_writable(&app, user.as_ref(), &owner, &name).await?; |
| 266 | let Some(user) = user else { |
| 267 | return Err(forbidden()); |
| 268 | }; |
| 269 | |
| 270 | let base_ref = if form.base_ref.trim().is_empty() { |
| 271 | repo.default_branch.clone() |
| 272 | } else { |
| 273 | form.base_ref.trim().to_string() |
| 274 | }; |
| 275 | let prompt = form.prompt.trim(); |
| 276 | let session_kind = if prompt.is_empty() { |
| 277 | kind::INTERACTIVE |
| 278 | } else { |
| 279 | kind::AUTONOMOUS |
| 280 | }; |
| 281 | |
| 282 | match anvil_agent::start(&app, repo.id, user.id, session_kind, &base_ref, prompt).await { |
| 283 | Ok(id) => Ok(Redirect::to(&format!("/{owner}/{name}/-/agent/{id}")).into_response()), |
| 284 | // Being at capacity, or switched off, is a normal answer rather than a |
| 285 | // fault — "something went wrong" would send someone hunting a bug that |
| 286 | // isn't there. |
| 287 | Err(e @ (StartError::Disabled | StartError::AtCapacity(_))) => Err(unavailable(&e)), |
| 288 | Err(e) => Err(server_error(e)), |
| 289 | } |
| 290 | } |
| 291 | |
| 292 | /// A session could not be started for a reason the caller can act on. |
| 293 | fn unavailable(reason: &StartError) -> Response { |
| 294 | ( |
| 295 | axum::http::StatusCode::SERVICE_UNAVAILABLE, |
| 296 | layout( |
| 297 | "Cannot start a session", |
| 298 | None, |
| 299 | html! { |
| 300 | h1 { "Cannot start a session" } |
| 301 | p.muted { (reason.to_string()) } |
| 302 | @if matches!(reason, StartError::AtCapacity(_)) { |
| 303 | p { "Stop a running session, or raise " code { "agent.max_concurrent" } "." } |
| 304 | } |
| 305 | }, |
| 306 | ), |
| 307 | ) |
| 308 | .into_response() |
| 309 | } |
| 310 | |
| 311 | #[derive(serde::Deserialize)] |
| 312 | struct CreateForm { |
| 313 | #[serde(default)] |
| 314 | csrf: String, |
| 315 | #[serde(default)] |
| 316 | base_ref: String, |
| 317 | #[serde(default)] |
| 318 | prompt: String, |
| 319 | } |
| 320 | |
| 321 | /// `POST /{owner}/{repo}/-/agent/{id}/stop` |
| 322 | async fn stop( |
| 323 | State(app): State<App>, |
| 324 | CurrentUser(user): CurrentUser, |
| 325 | csrf: Csrf, |
| 326 | Path((owner, name, id)): Path<(String, String, i64)>, |
| 327 | axum::Form(form): axum::Form<CsrfForm>, |
| 328 | ) -> Result<Response, Response> { |
| 329 | verify_csrf(&csrf, &form.csrf)?; |
| 330 | let repo = resolve_writable(&app, user.as_ref(), &owner, &name).await?; |
| 331 | let session = session_of(&app, repo.id, id).await?; |
| 332 | anvil_agent::stop(&app, session.id).await; |
| 333 | Ok(Redirect::to(&format!("/{owner}/{name}/-/agent/{id}")).into_response()) |
| 334 | } |
| 335 | |
| 336 | /// Load a session, checking it really belongs to this repository — otherwise |
| 337 | /// the id alone would read across repos. |
| 338 | async fn session_of( |
| 339 | app: &App, |
| 340 | repo_id: i64, |
| 341 | id: i64, |
| 342 | ) -> Result<anvil_core::AgentSession, Response> { |
| 343 | let session = agent::get(&app.db, id) |
| 344 | .await |
| 345 | .map_err(server_error)? |
| 346 | .ok_or_else(|| not_found("no such session"))?; |
| 347 | if session.repo_id != repo_id { |
| 348 | return Err(not_found("no such session")); |
| 349 | } |
| 350 | Ok(session) |
| 351 | } |
| 352 | |
| 353 | /// `GET /{owner}/{repo}/-/agent/{id}` — the terminal. |
| 354 | async fn show( |
| 355 | State(app): State<App>, |
| 356 | CurrentUser(user): CurrentUser, |
| 357 | Path((owner, name, id)): Path<(String, String, i64)>, |
| 358 | ) -> Result<Markup, Response> { |
| 359 | let repo = resolve_writable(&app, user.as_ref(), &owner, &name).await?; |
| 360 | let session = session_of(&app, repo.id, id).await?; |
| 361 | let live = status::is_live(&session.status); |
| 362 | let csrf = crate::auth::current_csrf(); |
| 363 | let ws_path = format!("/{owner}/{name}/-/agent/{id}/ws"); |
| 364 | |
| 365 | Ok(layout( |
| 366 | &format!("{owner}/{name} · agent #{id}"), |
| 367 | user.as_ref(), |
| 368 | html! { |
| 369 | h1 { "Agent session #" (id) } |
| 370 | p.muted { |
| 371 | (session.status) " · " (session.base_ref) " @ " |
| 372 | (short_commit(&session.base_commit)) |
| 373 | @if !session.error.is_empty() { " · " (session.error) } |
| 374 | } |
| 375 | @if live { |
| 376 | form method="post" action={(ws_path.trim_end_matches("/ws")) "/stop"} { |
| 377 | (ui::csrf_input(&csrf)) |
| 378 | button type="submit" { "Stop session" } |
| 379 | } |
| 380 | link rel="stylesheet" href="/-/static/wterm/terminal.css"; |
| 381 | div #terminal style="height:70vh" {} |
| 382 | script type="importmap" { |
| 383 | (PreEscaped(IMPORT_MAP)) |
| 384 | } |
| 385 | script type="module" { |
| 386 | (PreEscaped(format!("const WS_PATH = {};\n{}", |
| 387 | serde_json::to_string(&ws_path).unwrap_or_else(|_| "\"\"".into()), |
| 388 | TERMINAL_JS))) |
| 389 | } |
| 390 | } @else { |
| 391 | p { "This session has ended." } |
| 392 | } |
| 393 | }, |
| 394 | )) |
| 395 | } |
| 396 | |
| 397 | /// Resolves wterm's single bare specifier. Everything else in the vendored |
| 398 | /// tree imports by relative path. |
| 399 | const IMPORT_MAP: &str = r#"{"imports":{"@wterm/core":"/-/static/wterm/core/index.js"}}"#; |
| 400 | |
| 401 | /// Browser half of the terminal. |
| 402 | /// |
| 403 | /// Note the `htmx:beforeSwap` teardown: the layout sets `hx-boost` on `<body>`, |
| 404 | /// so navigating away swaps the DOM without a page load. Without this the |
| 405 | /// websocket and the WASM instance would leak on every navigation. |
| 406 | const TERMINAL_JS: &str = r#" |
| 407 | import { WTerm } from "/-/static/wterm/dom/index.js"; |
| 408 | |
| 409 | const url = new URL(WS_PATH, location.href); |
| 410 | url.protocol = location.protocol === "https:" ? "wss:" : "ws:"; |
| 411 | const ws = new WebSocket(url); |
| 412 | ws.binaryType = "arraybuffer"; |
| 413 | |
| 414 | const encode = new TextEncoder(); |
| 415 | let torndown = false; |
| 416 | |
| 417 | const sendResize = () => { |
| 418 | if (ws.readyState === WebSocket.OPEN) { |
| 419 | ws.send(JSON.stringify({ t: "resize", cols: term.cols, rows: term.rows })); |
| 420 | } |
| 421 | }; |
| 422 | |
| 423 | // Callbacks are read off the instance at call time, so setting them here (in |
| 424 | // the constructor options) is the same as setting them later — this is just |
| 425 | // the clearer place. `wasmUrl` is left unset on purpose: the built-in core's |
| 426 | // WASM is inlined as base64, so there is no second request to make. |
| 427 | const term = new WTerm(document.getElementById("terminal"), { |
| 428 | autoResize: true, |
| 429 | cursorBlink: true, |
| 430 | // Keystrokes out. onData hands us a string; the wire carries bytes. |
| 431 | onData: (data) => { |
| 432 | if (ws.readyState === WebSocket.OPEN) ws.send(encode.encode(data)); |
| 433 | }, |
| 434 | // Fires on the ResizeObserver as well as an explicit resize(), so the |
| 435 | // container's pty follows the browser window. |
| 436 | onResize: sendResize, |
| 437 | }); |
| 438 | await term.init(); |
| 439 | |
| 440 | ws.onopen = sendResize; |
| 441 | |
| 442 | ws.onmessage = (event) => { |
| 443 | // Binary is terminal bytes; text is our control channel. |
| 444 | if (event.data instanceof ArrayBuffer) { |
| 445 | term.write(new Uint8Array(event.data)); |
| 446 | return; |
| 447 | } |
| 448 | let msg; |
| 449 | try { |
| 450 | msg = JSON.parse(event.data); |
| 451 | } catch { |
| 452 | return; |
| 453 | } |
| 454 | if (msg.t === "exit") { |
| 455 | term.write("\r\n\x1b[2m[session ended, status " + msg.code + "]\x1b[0m\r\n"); |
| 456 | } else if (msg.t === "error") { |
| 457 | term.write("\r\n\x1b[31m[" + msg.message + "]\x1b[0m\r\n"); |
| 458 | } |
| 459 | }; |
| 460 | |
| 461 | ws.onclose = () => { |
| 462 | if (!torndown) term.write("\r\n\x1b[2m[disconnected]\x1b[0m\r\n"); |
| 463 | }; |
| 464 | |
| 465 | // The layout sets hx-boost on <body>, so navigating away swaps the DOM without |
| 466 | // a page load. Without this teardown the socket and the WASM instance would |
| 467 | // leak on every navigation. |
| 468 | const teardown = () => { |
| 469 | if (torndown) return; |
| 470 | torndown = true; |
| 471 | try { ws.close(); } catch {} |
| 472 | try { term.destroy(); } catch {} |
| 473 | }; |
| 474 | document.body.addEventListener("htmx:beforeSwap", teardown, { once: true }); |
| 475 | window.addEventListener("pagehide", teardown, { once: true }); |
| 476 | |
| 477 | term.focus(); |
| 478 | "#; |
| 479 | |
| 480 | // --- the websocket ---------------------------------------------------------- |
| 481 | |
| 482 | /// `GET /{owner}/{repo}/-/agent/{id}/ws` — bridge the browser to the |
| 483 | /// container's tmux. |
| 484 | async fn socket( |
| 485 | State(app): State<App>, |
| 486 | CurrentUser(user): CurrentUser, |
| 487 | Path((owner, name, id)): Path<(String, String, i64)>, |
| 488 | upgrade: WebSocketUpgrade, |
| 489 | ) -> Result<Response, Response> { |
| 490 | let repo = resolve_writable(&app, user.as_ref(), &owner, &name).await?; |
| 491 | let session = session_of(&app, repo.id, id).await?; |
| 492 | if !status::is_live(&session.status) { |
| 493 | return Err(not_found("session is not running")); |
| 494 | } |
| 495 | Ok(upgrade.on_upgrade(move |socket| bridge(app, session.id, socket))) |
| 496 | } |
| 497 | |
| 498 | /// Pump bytes between one websocket and one tmux client. |
| 499 | /// |
| 500 | /// Each browser gets its own `docker exec … tmux attach`, so a dropped socket |
| 501 | /// takes down that client and nothing else — the agent is a process inside |
| 502 | /// tmux, not a child of the exec. tmux repaints a newly attached client, which |
| 503 | /// is what makes reconnect show the current screen rather than a blank one. |
| 504 | async fn bridge(app: App, session_id: i64, socket: WebSocket) { |
| 505 | let (mut sink, mut stream) = socket.split(); |
| 506 | |
| 507 | let (terminal, docker) = match anvil_agent::attach_stream(&app, session_id, 80, 24).await { |
| 508 | Ok(attached) => attached, |
| 509 | Err(e) => { |
| 510 | let _ = sink |
| 511 | .send(Message::Text( |
| 512 | format!(r#"{{"t":"error","message":{}}}"#, json_string(&e)).into(), |
| 513 | )) |
| 514 | .await; |
| 515 | return; |
| 516 | } |
| 517 | }; |
| 518 | let anvil_agent::container::Terminal { |
| 519 | exec_id, |
| 520 | mut output, |
| 521 | mut input, |
| 522 | } = terminal; |
| 523 | |
| 524 | // Container -> browser. |
| 525 | let mut to_browser = tokio::spawn(async move { |
| 526 | while let Some(chunk) = output.next().await { |
| 527 | let Ok(log) = chunk else { break }; |
| 528 | let bytes = log.into_bytes(); |
| 529 | if bytes.is_empty() { |
| 530 | continue; |
| 531 | } |
| 532 | if sink |
| 533 | .send(Message::Binary(bytes.to_vec().into())) |
| 534 | .await |
| 535 | .is_err() |
| 536 | { |
| 537 | break; |
| 538 | } |
| 539 | } |
| 540 | let _ = sink.close().await; |
| 541 | }); |
| 542 | |
| 543 | // Browser -> container, plus the control channel. |
| 544 | let control_docker = docker.clone(); |
| 545 | let control_exec = exec_id.clone(); |
| 546 | let mut to_container = tokio::spawn(async move { |
| 547 | while let Some(message) = stream.next().await { |
| 548 | match message { |
| 549 | Ok(Message::Binary(data)) => { |
| 550 | if input.write_all(&data).await.is_err() { |
| 551 | break; |
| 552 | } |
| 553 | let _ = input.flush().await; |
| 554 | } |
| 555 | Ok(Message::Text(text)) => { |
| 556 | if let Some((cols, rows)) = parse_resize(&text) { |
| 557 | anvil_agent::container::resize(&control_docker, &control_exec, cols, rows) |
| 558 | .await; |
| 559 | } |
| 560 | } |
| 561 | Ok(Message::Close(_)) | Err(_) => break, |
| 562 | _ => {} |
| 563 | } |
| 564 | } |
| 565 | // Detach this tmux client explicitly. |
| 566 | // |
| 567 | // Docker has no "kill exec" call, and dropping bollard's streams does |
| 568 | // not reliably tear the exec down — without this, every page view left |
| 569 | // a tmux client attached forever, counting against the container's pids |
| 570 | // limit and taking part in tmux's window sizing. |
| 571 | // |
| 572 | // Writing the prefix (C-b) followed by `d` into the exec's own stdin |
| 573 | // detaches precisely the client on the other end of it, with no need to |
| 574 | // work out which of several clients is ours. `tmux.conf` keeps the |
| 575 | // default prefix, so this stays in step with it. |
| 576 | let _ = input.write_all(b"\x02d").await; |
| 577 | let _ = input.flush().await; |
| 578 | }); |
| 579 | |
| 580 | // Either direction ending means this viewer is gone. Abort BOTH halves |
| 581 | // rather than letting the survivor linger: each holds one end of bollard's |
| 582 | // hijacked connection, and while either is alive the `docker exec` — and so |
| 583 | // the tmux client behind it — stays up. Leaving them accumulated a stale |
| 584 | // client per page view, which counts against the container's pids limit and |
| 585 | // takes part in tmux's window sizing. |
| 586 | tokio::select! { |
| 587 | _ = &mut to_browser => {} |
| 588 | _ = &mut to_container => {} |
| 589 | } |
| 590 | to_browser.abort(); |
| 591 | to_container.abort(); |
| 592 | anvil_agent::detached(&app, session_id); |
| 593 | } |
| 594 | |
| 595 | /// Parse `{"t":"resize","cols":N,"rows":M}`. |
| 596 | fn parse_resize(text: &str) -> Option<(u16, u16)> { |
| 597 | let value: serde_json::Value = serde_json::from_str(text).ok()?; |
| 598 | if value.get("t")?.as_str()? != "resize" { |
| 599 | return None; |
| 600 | } |
| 601 | let cols = value.get("cols")?.as_u64()?.try_into().ok()?; |
| 602 | let rows = value.get("rows")?.as_u64()?.try_into().ok()?; |
| 603 | Some((cols, rows)) |
| 604 | } |
| 605 | |
| 606 | /// JSON-encode a string, for the small hand-built control messages. |
| 607 | fn json_string(s: &str) -> String { |
| 608 | serde_json::to_string(s).unwrap_or_else(|_| "\"\"".to_string()) |
| 609 | } |