catalog-backend: ignore relations when comparing entities

.changeset/heavy-ducks-raise.md

@@ -0,0 +1,5 @@
+---
+'@backstage/catalog-model': patch
+---
+
+Ignore relations when comparing entities. This stops the refresh loop from rewriting entities over and over.

packages/catalog-model/src/entity/util.ts

@@ -46,6 +46,10 @@ export function generateEntityEtag(): string {
  * are added or existing annotations were changed (since they are effectively
  * merged when doing updates).
  *
+ * Note that this comparison does NOT take state, relations or similar into
+ * account. It only compares the actual input entity data, i.e. metadata and
+ * spec.
+ *
  * @param previous The old state of the entity
  * @param next The new state of the entity
  */
@@ -76,6 +80,10 @@ export function entityHasChanges(previous: Entity, next: Entity): boolean {
   delete e1.metadata.annotations;
   delete e2.metadata.annotations;
 
+  // Remove things that we explicitly do not compare
+  delete e1.relations;
+  delete e2.relations;
+
   return !lodash.isEqual(e1, e2);
 }