Merge branch '309-empty-snapshot' into 'master'

fix: prevent panics if a clone snapshot has been deleted manually (#309)

See merge request postgres-ai/database-lab!399

Author: agneum

Diff for: internal/cloning/base.go

@@ -306,7 +306,10 @@ func (c *Base) DestroyClone(cloneID string) error {
 		}
 
 		c.deleteClone(cloneID)
-		c.decrementCloneNumber(w.Clone.Snapshot.ID)
+
+		if w.Clone.Snapshot != nil {
+			c.decrementCloneNumber(w.Clone.Snapshot.ID)
+		}
 		c.observingCh <- cloneID
 
 		c.SaveClonesState()

Diff for: internal/cloning/snapshots.go

@@ -34,7 +34,8 @@ func (c *Base) fetchSnapshots() error {
 		numClones := 0
 
 		for cloneName := range c.clones {
-			if c.clones[cloneName] != nil && c.clones[cloneName].Clone.Snapshot.ID == entry.ID {
+			if c.clones[cloneName] != nil && c.clones[cloneName].Clone.Snapshot != nil &&
+				c.clones[cloneName].Clone.Snapshot.ID == entry.ID {
 				numClones++
 			}
 		}

Diff for: internal/cloning/storage.go

@@ -62,10 +62,12 @@ func (c *Base) restartCloneContainers(ctx context.Context) {
 
 		if err := c.provision.ReconnectClone(ctx, cloneName); err != nil {
 			log.Err(fmt.Sprintf("Clone container %s cannot be reconnected to the internal network: %s", cloneName, err))
+			continue
 		}
 
 		if err := c.provision.StartCloneContainer(ctx, cloneName); err != nil {
 			log.Err(fmt.Sprintf("Clone container %s cannot start: %s", cloneName, err))
+			continue
 		}
 
 		log.Dbg(fmt.Sprintf("Clone container %s is running", cloneName))
@@ -79,7 +81,8 @@ func (c *Base) filterRunningClones(ctx context.Context) {
 	snapshotCache := make(map[string]struct{})
 
 	for cloneID, wrapper := range c.clones {
-		if wrapper.Clone == nil || wrapper.Session == nil || wrapper.Clone.Status.Code == models.StatusFatal {
+		if wrapper.Clone == nil || wrapper.Clone.Snapshot == nil || wrapper.Session == nil ||
+			wrapper.Clone.Status.Code == models.StatusFatal {
 			delete(c.clones, cloneID)
 			continue
 		}