Add GetResourceID to dstate and refactor callers (#4862)

## Changes

Adds GetResourceID(key) string returning the resource ID or empty string
if not found, replacing the bool-returning GetResourceEntry in all
callers that only needed the ID. Renames the implementation to
getResourceEntry (unexported); keeps GetResourceEntry public for the one
caller that also needs the State field.

## Why
Separate write users that only need access to ID and read users that
need full state. Preparing for WAL.

Author: denik

bundle/direct/apply.go

@@ -14,32 +14,23 @@ import (
 )
 
 func (d *DeploymentUnit) Destroy(ctx context.Context, db *dstate.DeploymentState) error {
-	entry, hasEntry := db.GetResourceEntry(d.ResourceKey)
-	if !hasEntry {
+	id := db.GetResourceID(d.ResourceKey)
+	if id == "" {
 		log.Infof(ctx, "Cannot delete %s: missing from state", d.ResourceKey)
 		return nil
 	}
 
-	if entry.ID == "" {
-		return errors.New("invalid state: empty id")
-	}
-
-	return d.Delete(ctx, db, entry.ID)
+	return d.Delete(ctx, db, id)
 }
 
 func (d *DeploymentUnit) Deploy(ctx context.Context, db *dstate.DeploymentState, newState any, actionType deployplan.ActionType, planEntry *deployplan.PlanEntry) error {
 	if actionType == deployplan.Create {
 		return d.Create(ctx, db, newState)
 	}
 
-	entry, hasEntry := db.GetResourceEntry(d.ResourceKey)
-	if !hasEntry {
-		return errors.New("state entry not found")
-	}
-
-	oldID := entry.ID
+	oldID := db.GetResourceID(d.ResourceKey)
 	if oldID == "" {
-		return errors.New("invalid state: empty id")
+		return errors.New("state entry not found")
 	}
 
 	switch actionType {

bundle/direct/bind.go

@@ -63,10 +63,10 @@ func (b *DeploymentBundle) Bind(ctx context.Context, client *databricks.Workspac
 	// Check if the resource is already managed (bound to a different ID)
 	var checkStateDB dstate.DeploymentState
 	if err := checkStateDB.Open(statePath); err == nil {
-		if existing, ok := checkStateDB.GetResourceEntry(resourceKey); ok {
+		if existingID := checkStateDB.GetResourceID(resourceKey); existingID != "" {
 			return nil, ErrResourceAlreadyBound{
 				ResourceKey: resourceKey,
-				ExistingID:  existing.ID,
+				ExistingID:  existingID,
 				NewID:       resourceID,
 			}
 		}

bundle/direct/bundle_apply.go

@@ -113,12 +113,12 @@ func (b *DeploymentBundle) Apply(ctx context.Context, client *databricks.Workspa
 
 			if migrateMode {
 				// In migration mode we're reading resources in DAG order so that we have fully resolved config snapshots stored
-				dbentry, hasEntry := b.StateDB.GetResourceEntry(resourceKey)
-				if !hasEntry || dbentry.ID == "" {
+				id := b.StateDB.GetResourceID(resourceKey)
+				if id == "" {
 					logdiag.LogError(ctx, fmt.Errorf("state entry not found for %q", resourceKey))
 					return false
 				}
-				err = b.StateDB.SaveState(resourceKey, dbentry.ID, sv.Value, entry.DependsOn)
+				err = b.StateDB.SaveState(resourceKey, id, sv.Value, entry.DependsOn)
 			} else {
 				// TODO: redo calcDiff to downgrade planned action if possible (?)
 				err = d.Deploy(ctx, &b.StateDB, sv.Value, action, entry)
@@ -135,13 +135,13 @@ func (b *DeploymentBundle) Apply(ctx context.Context, client *databricks.Workspa
 		//       already resolved and should not play a role here.
 		needRemoteState := len(g.Adj[resourceKey]) > 0
 		if needRemoteState {
-			entry, _ := b.StateDB.GetResourceEntry(d.ResourceKey)
-			if entry.ID == "" {
+			id := b.StateDB.GetResourceID(d.ResourceKey)
+			if id == "" {
 				logdiag.LogError(ctx, fmt.Errorf("%s: internal error: missing entry in state after deploy", errorPrefix))
 				return false
 			}
 
-			err = d.refreshRemoteState(ctx, entry.ID)
+			err = d.refreshRemoteState(ctx, id)
 			if err != nil {
 				logdiag.LogError(ctx, fmt.Errorf("%s: failed to read remote state: %w", errorPrefix, err))
 				return false
@@ -180,11 +180,11 @@ func (b *DeploymentBundle) LookupReferencePostDeploy(ctx context.Context, path *
 	}
 
 	if fieldPathS == "id" {
-		dbentry, hasEntry := b.StateDB.GetResourceEntry(targetResourceKey)
-		if !hasEntry || dbentry.ID == "" {
+		id := b.StateDB.GetResourceID(targetResourceKey)
+		if id == "" {
 			return nil, errors.New("internal error: no db entry")
 		}
-		return dbentry.ID, nil
+		return id, nil
 	}
 
 	remoteState, ok := b.RemoteStateCache.Load(targetResourceKey)

bundle/direct/bundle_plan.go

@@ -168,19 +168,19 @@ func (b *DeploymentBundle) CalculatePlan(ctx context.Context, client *databricks
 		}
 
 		if entry.Action == deployplan.Delete {
-			dbentry, hasEntry := b.StateDB.GetResourceEntry(resourceKey)
-			if !hasEntry {
+			id := b.StateDB.GetResourceID(resourceKey)
+			if id == "" {
 				logdiag.LogError(ctx, fmt.Errorf("%s: internal error, missing in state", errorPrefix))
 				return false
 			}
 
-			remoteState, err := adapter.DoRead(ctx, dbentry.ID)
+			remoteState, err := adapter.DoRead(ctx, id)
 			if err != nil {
 				if isResourceGone(err) {
 					// no such resource
 					plan.RemoveEntry(resourceKey)
 				} else {
-					log.Warnf(ctx, "reading %s id=%q: %s", resourceKey, dbentry.ID, err)
+					log.Warnf(ctx, "reading %s id=%q: %s", resourceKey, id, err)
 					// This is not an error during deletion, so don't return false here
 				}
 			}
@@ -605,12 +605,11 @@ func (b *DeploymentBundle) LookupReferencePreDeploy(ctx context.Context, path *s
 
 	if fieldPathS == "id" {
 		if targetAction.KeepsID() {
-			dbentry, hasEntry := b.StateDB.GetResourceEntry(targetResourceKey)
-			idValue := dbentry.ID
-			if !hasEntry || idValue == "" {
+			id := b.StateDB.GetResourceID(targetResourceKey)
+			if id == "" {
 				return nil, errors.New("internal error: no db entry")
 			}
-			return idValue, nil
+			return id, nil
 		}
 		// id may change after deployment, this needs to be done later
 		return nil, errDelayed

bundle/direct/dstate/state.go

@@ -84,7 +84,7 @@ func (db *DeploymentState) DeleteState(key string) error {
 	return nil
 }
 
-func (db *DeploymentState) GetResourceEntry(key string) (ResourceEntry, bool) {
+func (db *DeploymentState) getResourceEntry(key string) (ResourceEntry, bool) {
 	db.AssertOpened()
 	db.mu.Lock()
 	defer db.mu.Unlock()
@@ -97,6 +97,17 @@ func (db *DeploymentState) GetResourceEntry(key string) (ResourceEntry, bool) {
 	return result, ok
 }
 
+// GetResourceEntry returns the full resource entry for the given key.
+func (db *DeploymentState) GetResourceEntry(key string) (ResourceEntry, bool) {
+	return db.getResourceEntry(key)
+}
+
+// GetResourceID returns the ID of the resource for the given key, or an empty string if not found.
+func (db *DeploymentState) GetResourceID(key string) string {
+	entry, _ := db.getResourceEntry(key)
+	return entry.ID
+}
+
 func (db *DeploymentState) Open(path string) error {
 	db.mu.Lock()
 	defer db.mu.Unlock()