address code review: change interface method name to IsRunning

client/allocrunner/taskrunner/interfaces/lifecycle.go

@@ -17,9 +17,11 @@ type TaskLifecycle interface {
 	// Kill a task permanently.
 	Kill(ctx context.Context, event *structs.TaskEvent) error
 
-	// HasHandle returns true if the task runner has a handle to the task
+	// IsRunning returns true if the task runner has a handle to the task
 	// driver, which is useful for distinguishing restored tasks during
-	// prestart hooks. Note: prestart should be idempotent whenever possible
-	// to handle restored tasks safely; use this as an escape hatch.
-	HasHandle() bool
+	// prestart hooks. But note that the driver handle could go away after you
+	// check this, so callers should make sure they're handling that case
+	// safely. Ideally prestart hooks should be idempotnent whenever possible
+	// to handle restored tasks; use this as an escape hatch.
+	IsRunning() bool
 }

client/allocrunner/taskrunner/template/template.go

@@ -286,7 +286,7 @@ WAIT:
 
 			// if there's a driver handle then the task is already running and
 			// that changes how we want to behave on first render
-			if dirty && tm.config.Lifecycle.HasHandle() {
+			if dirty && tm.config.Lifecycle.IsRunning() {
 				handledRenders := make(map[string]time.Time, len(tm.config.Templates))
 				tm.onTemplateRendered(handledRenders, time.Time{})
 			}

client/allocrunner/taskrunner/template/template_test.go

@@ -101,7 +101,7 @@ func (m *MockTaskHooks) Kill(ctx context.Context, event *structs.TaskEvent) erro
 	return nil
 }
 
-func (m *MockTaskHooks) HasHandle() bool {
+func (m *MockTaskHooks) IsRunning() bool {
 	return m.hasHandle
 }