Method handleProcessOutput

agent/agentproc/api.go:152–217

handleProcessOutput returns the output of a process.

(rw http.ResponseWriter, r *http.Request)

// handleProcessOutput returns the output of a process.
func (api *API) handleProcessOutput(rw http.ResponseWriter, r *http.Request) {
	ctx := r.Context()
	logger := api.logger.With(agentchat.Fields(ctx)...)

	id := chi.URLParam(r, "id")
	proc, ok := api.manager.get(id)
	if !ok {
		httpapi.Write(ctx, rw, http.StatusNotFound, codersdk.Response{
			Message: fmt.Sprintf("Process %q not found.", id),
		})
		return
	}

	// Enforce chat ID isolation. If the request carries
	// a chat context, only allow access to processes
	// belonging to that chat.
	if chatContext, ok := agentchat.FromContext(ctx); ok {
		if proc.chatID != "" && proc.chatID != chatContext.ID.String() {
			httpapi.Write(ctx, rw, http.StatusNotFound, codersdk.Response{
				Message: fmt.Sprintf("Process %q not found.", id),
			})
			return
		}
	}

	// Check for blocking mode via query params.
	waitStr := r.URL.Query().Get("wait")
	wantWait := waitStr == "true"

	if wantWait {
		// Extend the write deadline so the HTTP server's
		// WriteTimeout does not kill the connection while
		// we block.
		rc := http.NewResponseController(rw)
		// Add headroom beyond the wait timeout so there's time to
		// write the response after the blocking wait completes.
		if err := rc.SetWriteDeadline(time.Now().Add(maxWaitDuration + 30*time.Second)); err != nil {
			logger.Error(ctx, "extend write deadline for blocking process output",
				slog.Error(err),
			)
		}

		// Cap the wait at maxWaitDuration regardless of
		// client-supplied timeout.
		waitCtx, waitCancel := context.WithTimeout(ctx, maxWaitDuration)
		defer waitCancel()

		_ = proc.waitForOutput(waitCtx)
		// Fall through to read snapshot below.
	}

	// Read info before output to avoid a TOCTOU race. The exit
	// goroutine completes all buffer writes (cmd.Wait) before
	// setting running=false, so if info reports the process as
	// exited, the subsequent output read is guaranteed to reflect
	// the final buffer state.
	info := proc.info()
	output, truncated := proc.output()