liveupdate: fix handling of docker-compose restarts

Fixes #5663

internal/controllers/core/liveupdate/reconciler.go

@@ -514,14 +514,17 @@ func (r *Reconciler) garbageCollectFileChanges(res luResource, monitor *monitor)
 // Go through all the container monitors, and delete any that are no longer
 // being selected. We don't care why they're not being selected.
 func (r *Reconciler) garbageCollectMonitorContainers(res luResource, monitor *monitor) {
-	podsByKey := map[monitorContainerKey]bool{}
-	for _, pod := range res.podNames() {
-		podsByKey[monitorContainerKey{podName: pod.Name, namespace: pod.Namespace}] = true
-	}
+	// All containers are guaranteed to have container IDs if they're still active.
+	containerIDs := map[string]bool{}
+	res.visitSelectedContainers(func(pod v1alpha1.Pod, c v1alpha1.Container) bool {
+		if c.ID != "" {
+			containerIDs[c.ID] = true
+		}
+		return false
+	})
 
 	for key := range monitor.containers {
-		podKey := monitorContainerKey{podName: key.podName, namespace: key.namespace}
-		if !podsByKey[podKey] {
+		if !containerIDs[key.containerID] {
 			delete(monitor.containers, key)
 		}
 	}
@@ -966,7 +969,7 @@ func (r *Reconciler) applyInternal(
 			ContainerName:      cInfo.ContainerName.String(),
 			ContainerID:        cInfo.ContainerID.String(),
 			PodName:            cInfo.PodID.String(),
-			Namespace:          cInfo.Namespace.String(),
+			Namespace:          string(cInfo.Namespace),
 			LastFileTimeSynced: lastFileTimeSynced,
 		}
 

internal/controllers/core/liveupdate/reconciler_test.go

@@ -182,6 +182,18 @@ func TestConsumeFileEventsDockerCompose(t *testing.T) {
 	if assert.Equal(t, 1, len(f.cu.Calls)) {
 		assert.True(t, f.cu.Calls[0].HotReload)
 	}
+
+	f.assertSteadyState(&lu)
+
+	// Docker Compose containers can be restarted in-place,
+	// preserving their filesystem.
+	dc := &v1alpha1.DockerComposeService{}
+	f.MustGet(types.NamespacedName{Name: "frontend-service"}, dc)
+	dc = dc.DeepCopy()
+	dc.Status.ContainerState.StartedAt = apis.NowMicro()
+	f.UpdateStatus(dc)
+
+	f.assertSteadyState(&lu)
 }
 
 func TestConsumeFileEventsUpdateModeManual(t *testing.T) {

internal/controllers/core/liveupdate/resource.go

@@ -4,7 +4,6 @@ import (
 	"time"
 
 	"github.com/docker/distribution/reference"
-	"k8s.io/apimachinery/pkg/types"
 
 	"github.com/tilt-dev/tilt/internal/container"
 	"github.com/tilt-dev/tilt/internal/dockercompose"
@@ -22,9 +21,6 @@ type luResource interface {
 	// The time to start syncing changes from.
 	bestStartTime() time.Time
 
-	// The names of any pods, for tracking state.
-	podNames() []types.NamespacedName
-
 	// An iterator for visiting each container.
 	visitSelectedContainers(visit func(pod v1alpha1.Pod, c v1alpha1.Container) bool)
 }
@@ -48,14 +44,6 @@ func (r *luK8sResource) bestStartTime() time.Time {
 	return startTime
 }
 
-func (r *luK8sResource) podNames() []types.NamespacedName {
-	result := []types.NamespacedName{}
-	for _, pod := range r.res.FilteredPods {
-		result = append(result, types.NamespacedName{Name: pod.Name, Namespace: pod.Namespace})
-	}
-	return result
-}
-
 // Visit all selected containers.
 func (r *luK8sResource) visitSelectedContainers(
 	visit func(pod v1alpha1.Pod, c v1alpha1.Container) bool) {
@@ -94,15 +82,6 @@ func (r *luDCResource) bestStartTime() time.Time {
 	return r.res.Status.LastApplyStartTime.Time
 }
 
-// In DockerCompose, we treat every container as a single-container pod.
-func (r *luDCResource) podNames() []types.NamespacedName {
-	result := []types.NamespacedName{}
-	if r.res.Status.ContainerID != "" {
-		result = append(result, types.NamespacedName{Name: r.res.Status.ContainerID})
-	}
-	return result
-}
-
 // Visit all selected containers.
 func (r *luDCResource) visitSelectedContainers(
 	visit func(pod v1alpha1.Pod, c v1alpha1.Container) bool) {