Worker: fix race condition getting logger with worker status

internal/worker/state_asleep.go

@@ -6,8 +6,6 @@ import (
 	"context"
 	"time"
 
-	"github.com/rs/zerolog/log"
-
 	"git.blender.org/flamenco/pkg/api"
 )
 
@@ -25,7 +23,7 @@ func (w *Worker) gotoStateAsleep(ctx context.Context) {
 
 func (w *Worker) runStateAsleep(ctx context.Context) {
 	defer w.doneWg.Done()
-	logger := log.With().Str("status", string(w.state)).Logger()
+	logger := w.loggerWithStatus()
 	logger.Info().Msg("sleeping")
 
 	for {

internal/worker/state_awake.go

@@ -36,9 +36,9 @@ func (w *Worker) runStateAwake(ctx context.Context) {
 		err := recover()
 		if err != nil {
 			w.SignOff(ctx)
-			log.Panic().
+			logger := w.loggerWithStatus()
+			logger.Panic().
 				Interface("panic", err).
-				Str("workerStatus", string(w.state)).
 				Msg("panic, so signed off and going to stop")
 		}
 	}()
@@ -71,7 +71,7 @@ func (w *Worker) runStateAwake(ctx context.Context) {
 // fetchTasks periodically tries to fetch a task from the Manager, returning it when obtained.
 // Returns nil when a task could not be obtained and the period loop was cancelled.
 func (w *Worker) fetchTask(ctx context.Context) *api.AssignedTask {
-	logger := log.With().Str("status", string(w.state)).Logger()
+	logger := w.loggerWithStatus()
 
 	// Initially don't wait at all.
 	var wait time.Duration

internal/worker/statemachine.go

@@ -5,6 +5,7 @@ package worker
 import (
 	"context"
 
+	"github.com/rs/zerolog"
 	"github.com/rs/zerolog/log"
 
 	"git.blender.org/flamenco/pkg/api"
@@ -65,3 +66,13 @@ func (w *Worker) ackStateChange(ctx context.Context, state api.WorkerStatus) {
 		return
 	}
 }
+
+// loggerWithStatus returns a logger with its current status mentioned.
+// This is a thread-safe way of getting the logger.
+func (w *Worker) loggerWithStatus() zerolog.Logger {
+	w.stateMutex.Lock()
+	defer w.stateMutex.Unlock()
+
+	logger := log.With().Str("workerStatus", string(w.state)).Logger()
+	return logger
+}