Fix AlertmanagerConfig create failing on 109+ validating webhook (#17351) (#17617)

* Fix AlertmanagerConfig create failing on 109+ validating webhook

Stop seeding the bad `match`, `matchRe`, and `receivers` defaults on
`spec.route` that never matched the CRD schema, drop an unreferenced
root route on save, and migrate any legacy map entries into `matchers`
so they round-trip cleanly on both <=108 and 109+ charts.

Fixes #17347

* Strip invalid route fields on save without migration

Drop the matchers-migration branch and simply strip match, matchRe,
and route.receivers on cleanForSave. Those fields are never valid on
the AlertmanagerConfig CRD schema; any populated value in the wild
only exists because a hand-edited YAML copied alertmanager.yml syntax,
which wouldn't have worked anyway. Tests updated to match.

* Fix tests to match committed behavior

The previous test file asserted against a migration helper that was
not in the committed code. Rewrite the tests to cover what the model
actually does: seed correct route defaults on load and drop spec.route
on save when no receiver is set.

Author: codyrancher

shell/models/__tests__/monitoring.coreos.com.alertmanagerconfig.test.ts

@@ -0,0 +1,98 @@
+import AlertmanagerConfig from '@shell/models/monitoring.coreos.com.alertmanagerconfig';
+
+const base = {
+  apiVersion: 'monitoring.coreos.com/v1alpha1',
+  kind:       'AlertmanagerConfig',
+  metadata:   { name: 'test', namespace: 'default' },
+};
+
+const build = (data: Record<string, any>) => new AlertmanagerConfig(data) as any;
+
+describe('class AlertmanagerConfig', () => {
+  describe('applyDefaults', () => {
+    it('on a fresh resource, seeds the route with defaults and no match/matchRe', () => {
+      const amc = build({ ...base });
+
+      amc.applyDefaults();
+
+      expect(amc.spec.receivers).toStrictEqual([]);
+      expect(amc.spec.route).toStrictEqual({
+        groupBy:        [],
+        groupWait:      '30s',
+        groupInterval:  '5m',
+        repeatInterval: '4h',
+        matchers:       [],
+      });
+    });
+
+    it('backfills route defaults on a resource loaded without a route', () => {
+      const amc = build({
+        ...base,
+        spec: { receivers: [{ name: 'existing' }] },
+      });
+
+      amc.applyDefaults();
+
+      expect(amc.spec.route).toBeDefined();
+      expect(amc.spec.route.receiver).toBeUndefined();
+      expect(amc.spec.route.matchers).toStrictEqual([]);
+    });
+
+    it('preserves existing matchers on load', () => {
+      const matchers = [{
+        name: 'severity', value: 'warning', matchType: '='
+      }];
+      const amc = build({
+        ...base,
+        spec: {
+          receivers: [{ name: 'existing' }],
+          route:     { receiver: 'existing', matchers },
+        },
+      });
+
+      amc.applyDefaults();
+
+      expect(amc.spec.route.matchers).toStrictEqual(matchers);
+    });
+  });
+
+  describe('cleanForSave', () => {
+    it('drops spec.route when no receiver is set — this is what fixes #17347 on 109+ charts', () => {
+      const amc = build({ ...base });
+
+      const out = amc.cleanForSave({
+        ...base,
+        spec: {
+          receivers: [],
+          route:     {
+            groupBy:        [],
+            groupWait:      '30s',
+            groupInterval:  '5m',
+            repeatInterval: '4h',
+            matchers:       [],
+          },
+        },
+      }, true);
+
+      expect(out.spec.route).toBeUndefined();
+      expect(out.spec.receivers).toStrictEqual([]);
+    });
+
+    it('keeps spec.route when a receiver is set', () => {
+      const amc = build({ ...base });
+
+      const out = amc.cleanForSave({
+        ...base,
+        spec: {
+          receivers: [{ name: 'existing' }],
+          route:     {
+            receiver: 'existing', groupBy: [], matchers: []
+          },
+        },
+      }, false);
+
+      expect(out.spec.route).toBeDefined();
+      expect(out.spec.route.receiver).toBe('existing');
+    });
+  });
+});

shell/models/monitoring.coreos.com.alertmanagerconfig.js

@@ -5,25 +5,39 @@ import { set } from '@shell/utils/object';
 
 export default class AlertmanagerConfig extends SteveModel {
   applyDefaults() {
-    if (this.spec) {
-      return this.spec;
-    }
-    const existingReceivers = this.spec?.route?.receivers || [];
-
-    const defaultSpec = {
-      receivers: [...existingReceivers],
-      route:     {
-        receivers:      this.spec?.route?.receivers || [],
-        groupBy:        this.spec?.route?.groupBy || [],
-        groupWait:      this.spec?.route?.groupWait || '30s',
-        groupInterval:  this.spec?.route?.groupInterval || '5m',
-        repeatInterval: this.spec?.route?.repeatInterval || '4h',
-        match:          this.spec?.route?.match || {},
-        matchRe:        this.spec?.route?.matchRe || {}
+    const spec = this.spec || {};
+
+    spec.receivers = spec.receivers || [];
+
+    // Always provide a route object so the Route tab has something to bind to,
+    // even when loading a resource that was saved without `spec.route`.
+    const route = { ...(spec.route || {}) };
+
+    route.groupBy = route.groupBy || [];
+    route.groupWait = route.groupWait || '30s';
+    route.groupInterval = route.groupInterval || '5m';
+    route.repeatInterval = route.repeatInterval || '4h';
+    route.matchers = route.matchers || [];
+
+    spec.route = route;
+
+    set(this, 'spec', spec);
+  }
+
+  cleanForSave(data, forNew) {
+    const val = super.cleanForSave(data, forNew);
+    const route = val?.spec?.route;
+
+    if (route) {
+      // When a route is present its `receiver` is required and must match an
+      // entry in `spec.receivers`. Until the user has defined a receiver the
+      // root route can't direct alerts anywhere, so drop it entirely
+      if (!route.receiver) {
+        delete val.spec.route;
       }
-    };
+    }
 
-    set(this, 'spec', defaultSpec);
+    return val;
   }
 
   get _availableActions() {