Line data    Source code

       1              : use std::sync::Arc;
       2              : 
       3              : use axum::{extract::State, response::Response};
       4              : use compute_api::{
       5              :     requests::ConfigurationRequest,
       6              :     responses::{ComputeStatus, ComputeStatusResponse},
       7              : };
       8              : use http::StatusCode;
       9              : use tokio::task;
      10              : use tracing::info;
      11              : 
      12              : use crate::{
      13              :     compute::{ComputeNode, ParsedSpec},
      14              :     http::{extract::Json, JsonResponse},
      15              : };
      16              : 
      17              : // Accept spec in JSON format and request compute configuration. If anything
      18              : // goes wrong after we set the compute status to `ConfigurationPending` and
      19              : // update compute state with new spec, we basically leave compute in the
      20              : // potentially wrong state. That said, it's control-plane's responsibility to
      21              : // watch compute state after reconfiguration request and to clean restart in
      22              : // case of errors.
      23            0 : pub(in crate::http) async fn configure(
      24            0 :     State(compute): State<Arc<ComputeNode>>,
      25            0 :     request: Json<ConfigurationRequest>,
      26            0 : ) -> Response {
      27            0 :     if !compute.live_config_allowed {
      28            0 :         return JsonResponse::error(
      29            0 :             StatusCode::PRECONDITION_FAILED,
      30            0 :             "live configuration is not allowed for this compute node".to_string(),
      31            0 :         );
      32            0 :     }
      33              : 
      34            0 :     let pspec = match ParsedSpec::try_from(request.spec.clone()) {
      35            0 :         Ok(p) => p,
      36            0 :         Err(e) => return JsonResponse::error(StatusCode::BAD_REQUEST, e),
      37              :     };
      38              : 
      39              :     // XXX: wrap state update under lock in a code block. Otherwise, we will try
      40              :     // to `Send` `mut state` into the spawned thread bellow, which will cause
      41              :     // the following rustc error:
      42              :     //
      43              :     // error: future cannot be sent between threads safely
      44              :     {
      45            0 :         let mut state = compute.state.lock().unwrap();
      46            0 :         if !matches!(state.status, ComputeStatus::Empty | ComputeStatus::Running) {
      47            0 :             return JsonResponse::invalid_status(state.status);
      48            0 :         }
      49            0 : 
      50            0 :         state.pspec = Some(pspec);
      51            0 :         state.set_status(ComputeStatus::ConfigurationPending, &compute.state_changed);
      52            0 :         drop(state);
      53            0 :     }
      54            0 : 
      55            0 :     // Spawn a blocking thread to wait for compute to become Running. This is
      56            0 :     // needed to do not block the main pool of workers and be able to serve
      57            0 :     // other requests while some particular request is waiting for compute to
      58            0 :     // finish configuration.
      59            0 :     let c = compute.clone();
      60            0 :     let completed = task::spawn_blocking(move || {
      61            0 :         let mut state = c.state.lock().unwrap();
      62            0 :         while state.status != ComputeStatus::Running {
      63            0 :             state = c.state_changed.wait(state).unwrap();
      64            0 :             info!(
      65            0 :                 "waiting for compute to become {}, current status: {}",
      66            0 :                 ComputeStatus::Running,
      67            0 :                 state.status
      68              :             );
      69              : 
      70            0 :             if state.status == ComputeStatus::Failed {
      71            0 :                 let err = state.error.as_ref().map_or("unknown error", |x| x);
      72            0 :                 let msg = format!("compute configuration failed: {:?}", err);
      73            0 :                 return Err(msg);
      74            0 :             }
      75              :         }
      76              : 
      77            0 :         Ok(())
      78            0 :     })
      79            0 :     .await
      80            0 :     .unwrap();
      81              : 
      82            0 :     if let Err(e) = completed {
      83            0 :         return JsonResponse::error(StatusCode::INTERNAL_SERVER_ERROR, e);
      84            0 :     }
      85            0 : 
      86            0 :     // Return current compute state if everything went well.
      87            0 :     let state = compute.state.lock().unwrap().clone();
      88            0 :     let body = ComputeStatusResponse::from(&state);
      89            0 : 
      90            0 :     JsonResponse::success(StatusCode::OK, body)
      91            0 : }