Merge branch 'worktree-task-cancellation': task cancellation feature

# Conflicts:
#	packages/cloud-platform/cloud/schema.py

apps/device-host-agent/host_agent/web/app.py

@@ -41,7 +41,9 @@ CSRF_FORM_FIELD = "csrf_token"
 _LOOPBACK_BIND_HOSTS = frozenset({"127.0.0.1", "localhost", "::1"})
 
 TaskSubmissionCallable = Callable[..., Awaitable[str]]
+TaskCancellationCallable = Callable[..., Awaitable[Any]]
 AUTOMATIC_DEVICE_VALUE = "__automatic__"
+_TERMINAL_LOCAL_TASK_STATUSES = frozenset({"completed", "failed", "cancelled"})
 
 _ENV = jinja2.Environment(
     loader=jinja2.FileSystemLoader(Path(__file__).parent / "templates"),
@@ -217,6 +219,7 @@ def create_console_app(
     enrollment_client: HostAgentEnrollmentClient | None,
     host_client: HostAgentClient | None = None,
     submit_self_task: TaskSubmissionCallable | None = None,
+    cancel_task: TaskCancellationCallable | None = None,
     metadata_store: TaskMetadataStore | None = None,
     timeline: Timeline | None = None,
     executor: AssignmentExecutor | None = None,
@@ -225,6 +228,8 @@ def create_console_app(
     cookie_secure = config.console_bind_host not in _LOOPBACK_BIND_HOSTS
     if submit_self_task is None and host_client is not None:
         submit_self_task = host_client.submit_self_task
+    if cancel_task is None and host_client is not None:
+        cancel_task = host_client.cancel_task
     submission_available = submit_self_task is not None
 
     def _running_devices() -> list[dict[str, str]]:
@@ -709,6 +714,7 @@ def create_console_app(
     @app.get("/tasks/{task_id}", response_class=HTMLResponse)
     async def task_detail_page(
         task_id: str,
+        request: Request,
         session: SessionState = Depends(require_session),
     ) -> HTMLResponse:
         if metadata_store is None:
@@ -738,13 +744,57 @@ def create_console_app(
             if task.get(key) is not None
         ]
         timeline_steps = [_timeline_step_context(record) for record in timeline_records]
+        can_cancel = (
+            cancel_task is not None
+            and task.get("source_task_id") is not None
+            and task.get("status") not in _TERMINAL_LOCAL_TASK_STATUSES
+        )
+        cancel_notice = (
+            "Cancellation requested. It may take a moment to take effect."
+            if request.query_params.get("cancelled") == "1"
+            else None
+        )
+        cancel_error = (
+            "Failed to request cancellation. Try again."
+            if request.query_params.get("cancel_error") == "1"
+            else None
+        )
         return _render(
             "task_detail.html",
             title=f"Task {task_id}",
             session=session,
+            csrf_token=session.csrf_token,
             task=task,
             task_rows=task_rows,
             timeline_steps=timeline_steps,
+            can_cancel=can_cancel,
+            cancel_notice=cancel_notice,
+            cancel_error=cancel_error,
         )
 
+    @app.post("/tasks/{task_id}/cancel")
+    async def tasks_cancel(
+        task_id: str,
+        session: SessionState = Depends(require_csrf),
+    ) -> Response:
+        if metadata_store is None:
+            raise HTTPException(
+                status_code=503, detail="task metadata store not configured"
+            )
+        task = await asyncio.to_thread(metadata_store.get_task, task_id)
+        if task is None:
+            raise HTTPException(status_code=404, detail="task not found")
+        source_task_id = task.get("source_task_id")
+        if cancel_task is None or source_task_id is None:
+            return RedirectResponse(
+                url=f"/tasks/{task_id}?cancel_error=1", status_code=303
+            )
+        try:
+            await cancel_task(source_task_id)
+        except HostAgentAPIError:
+            return RedirectResponse(
+                url=f"/tasks/{task_id}?cancel_error=1", status_code=303
+            )
+        return RedirectResponse(url=f"/tasks/{task_id}?cancelled=1", status_code=303)
+
     return app

apps/device-host-agent/host_agent/web/templates/task_detail.html

@@ -42,6 +42,14 @@
       <thead><tr><th>Field</th><th>Value</th></tr></thead>
       <tbody>{% for row in task_rows %}<tr><td>{{ row[0] }}</td><td>{{ row[1] }}</td></tr>{% endfor %}</tbody>
     </table>
+    {% if cancel_notice %}<p class="notice" id="cancel-notice">{{ cancel_notice }}</p>{% endif %}
+    {% if cancel_error %}<p class="error" id="cancel-error">{{ cancel_error }}</p>{% endif %}
+    {% if can_cancel %}
+    <form method="post" action="/tasks/{{ task['id'] }}/cancel">
+      <input type="hidden" name="csrf_token" value="{{ csrf_token }}">
+      <p><button type="submit">Cancel task</button></p>
+    </form>
+    {% endif %}
     <h2>Timeline</h2>
     {% if not timeline_steps %}
     <p>No timeline records.</p>