fix: not failing the main loop when one NodeGroup fails on TemplateNodeInfo() (#8402)

* fix: not failing the main loop when one NodeGroup fails on TemplateNodeInfo()

* test: add a unit test

Author: comtalyst

cluster-autoscaler/processors/nodeinfosprovider/mixed_nodeinfos_processor.go

@@ -140,12 +140,10 @@ func (p *MixedTemplateNodeInfoProvider) Process(ctx *context.AutoscalingContext,
 		// working nodes in the node groups. By default CA tries to use a real-world example.
 		nodeInfo, err := simulator.SanitizedTemplateNodeInfoFromNodeGroup(nodeGroup, daemonsets, taintConfig)
 		if err != nil {
-			if errors.Is(err, cloudprovider.ErrNotImplemented) {
-				continue
-			} else {
+			if !errors.Is(err, cloudprovider.ErrNotImplemented) {
 				klog.Errorf("Unable to build proper template node for %s: %v", id, err)
-				return map[string]*framework.NodeInfo{}, caerror.ToAutoscalerError(caerror.CloudProviderError, err)
 			}
+			continue
 		}
 		result[id] = nodeInfo
 	}

cluster-autoscaler/processors/nodeinfosprovider/mixed_nodeinfos_processor_test.go

@@ -302,6 +302,35 @@ func TestGetNodeInfosCacheExpired(t *testing.T) {
 
 }
 
+func TestProcessHandlesTemplateNodeInfoErrors(t *testing.T) {
+	now := time.Now()
+
+	tn := BuildTestNode("tn", 1000, 1000)
+	tni := framework.NewTestNodeInfo(tn)
+
+	provider := testprovider.NewTestCloudProviderBuilder().WithMachineTemplates(
+		map[string]*framework.NodeInfo{"ng2": tni}).Build()
+
+	provider.AddNodeGroup("ng1", 0, 10, 0)
+	provider.AddNodeGroup("ng2", 0, 10, 0)
+
+	ctx := context.AutoscalingContext{
+		CloudProvider:   provider,
+		ClusterSnapshot: testsnapshot.NewTestSnapshotOrDie(t),
+	}
+
+	res, err := NewMixedTemplateNodeInfoProvider(&cacheTtl, false).Process(&ctx, []*apiv1.Node{}, []*appsv1.DaemonSet{}, taints.TaintConfig{}, now)
+
+	// Should not fail despite ng1 error - continues processing
+	assert.NoError(t, err)
+	assert.Equal(t, 1, len(res))
+
+	_, found := res["ng2"]
+	assert.True(t, found)
+	_, found = res["ng1"]
+	assert.False(t, found) // ng1 skipped due to template error
+}
+
 func assertEqualNodeCapacities(t *testing.T, expected, actual *apiv1.Node) {
 	t.Helper()
 	assert.NotEqual(t, actual.Status, nil, "")