Feature/service metadata fixes 2 (#90)

* Check for available API resources on startup

* Improve field parsing

---------

Co-authored-by: aalexand <aalexand@adobe.com>

.gitignore

@@ -10,7 +10,7 @@ docker/
 
 # build artifacts
 /cluster-registry*
-kubeconfig
+kubeconfig*
 .dynamodb
 .hack*
 

cmd/client/client.go

@@ -15,13 +15,15 @@ package main
 import (
 	"encoding/base64"
 	"flag"
+	"fmt"
 	registryv1alpha1 "github.com/adobe/cluster-registry/pkg/api/registry/v1alpha1"
 	"github.com/adobe/cluster-registry/pkg/client/controllers"
 	"github.com/adobe/cluster-registry/pkg/config"
 	monitoring "github.com/adobe/cluster-registry/pkg/monitoring/client"
 	"github.com/adobe/cluster-registry/pkg/sqs"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 	"k8s.io/apimachinery/pkg/runtime/schema"
+	"k8s.io/client-go/discovery"
 	"k8s.io/client-go/tools/leaderelection/resourcelock"
 	"os"
 
@@ -148,20 +150,10 @@ func main() {
 	}
 
 	if err = (&controllers.ServiceMetadataWatcherReconciler{
-		Client: mgr.GetClient(),
-		Log:    ctrl.Log.WithName("controllers").WithName("ServiceMetadataWatcher"),
-		Scheme: mgr.GetScheme(),
-		WatchedGVKs: func(cfg configv1.ClientConfig) []schema.GroupVersionKind {
-			var GVKs []schema.GroupVersionKind
-			for _, gvk := range cfg.ServiceMetadata.WatchedGVKs {
-				GVKs = append(GVKs, schema.GroupVersionKind{
-					Group:   gvk.Group,
-					Version: gvk.Version,
-					Kind:    gvk.Kind,
-				})
-			}
-			return GVKs
-		}(clientConfig),
+		Client:              mgr.GetClient(),
+		Log:                 ctrl.Log.WithName("controllers").WithName("ServiceMetadataWatcher"),
+		Scheme:              mgr.GetScheme(),
+		WatchedGVKs:         loadWatchedGVKs(clientConfig),
 		ServiceIdAnnotation: clientConfig.ServiceMetadata.ServiceIdAnnotation,
 	}).SetupWithManager(ctx, mgr); err != nil {
 		setupLog.Error(err, "unable to create controller", "controller", "ServiceMetadataWatcher")
@@ -204,6 +196,27 @@ func main() {
 	}
 }
 
+func loadWatchedGVKs(cfg configv1.ClientConfig) []schema.GroupVersionKind {
+	availableGVKs, err := getAvailableGVKs()
+	if err != nil {
+		return []schema.GroupVersionKind{}
+	}
+	var GVKs []schema.GroupVersionKind
+	for _, gvk := range cfg.ServiceMetadata.WatchedGVKs {
+		gvk := schema.GroupVersionKind{
+			Group:   gvk.Group,
+			Version: gvk.Version,
+			Kind:    gvk.Kind,
+		}
+		if _, found := availableGVKs[gvk]; !found {
+			setupLog.Info("GVK not installed in the cluster", "gvk", gvk)
+			continue
+		}
+		GVKs = append(GVKs, gvk)
+	}
+	return GVKs
+}
+
 func apply(configFile string, clientConfigDefaults *configv1.ClientConfig) (ctrl.Options, configv1.ClientConfig, error) {
 	options, cfg, err := configv1.Load(scheme, configFile, clientConfigDefaults)
 	if err != nil {
@@ -218,3 +231,30 @@ func apply(configFile string, clientConfigDefaults *configv1.ClientConfig) (ctrl
 
 	return options, cfg, nil
 }
+
+func getAvailableGVKs() (map[schema.GroupVersionKind]bool, error) {
+	discoveryClient, err := discovery.NewDiscoveryClientForConfig(ctrl.GetConfigOrDie())
+	if err != nil {
+		return nil, fmt.Errorf("unable to create discovery client: %w", err)
+	}
+
+	_, availableResources, err := discoveryClient.ServerGroupsAndResources()
+	if err != nil {
+		return nil, fmt.Errorf("unable to get available API resources: %w", err)
+	}
+
+	availableGVKs := make(map[schema.GroupVersionKind]bool)
+	for _, list := range availableResources {
+		groupVersion, _ := schema.ParseGroupVersion(list.GroupVersion)
+		for _, resource := range list.APIResources {
+			gvk := schema.GroupVersionKind{
+				Group:   groupVersion.Group,
+				Version: groupVersion.Version,
+				Kind:    resource.Kind,
+			}
+			availableGVKs[gvk] = true
+		}
+	}
+
+	return availableGVKs, nil
+}

pkg/client/controllers/servicemetadatawatcher_controller.go

@@ -131,7 +131,14 @@ func (r *ServiceMetadataWatcherReconciler) Reconcile(ctx context.Context, req ct
 		for _, field := range wso.WatchedFields {
 			// TODO: validate field Source & Destination somewhere
 
-			value, found, err := getNestedString(obj.Object, strings.Split(field.Source, "."))
+			path, err := parsePath(field.Source)
+			if err != nil {
+				// TODO: update status with error
+				log.Error(err, "cannot parse path", "field", field.Source)
+				continue
+			}
+
+			value, found, err := getNestedString(obj.Object, path)
 			if err != nil {
 				// TODO: update status with error
 				log.Error(err, "cannot get field", "field", field.Source)
@@ -165,6 +172,15 @@ func (r *ServiceMetadataWatcherReconciler) Reconcile(ctx context.Context, req ct
 	return noRequeue()
 }
 
+func parsePath(path string) ([]string, error) {
+	re := regexp.MustCompile(`(?:[^.\[]+|\[.*?\])`)
+	p := re.FindAllString(path, -1)
+	if len(p) > 0 {
+		return p, nil
+	}
+	return nil, fmt.Errorf("invalid path")
+}
+
 // SetupWithManager sets up the controller with the Manager.
 func (r *ServiceMetadataWatcherReconciler) SetupWithManager(ctx context.Context, mgr ctrl.Manager) error {
 	options := controller.Options{MaxConcurrentReconciles: 10}
@@ -318,32 +334,40 @@ func createServiceMetadataPatch(serviceId string, namespace string, field string
 }
 
 // getNestedString returns the value of a nested field in the provided object
-// path is a list of keys separated by dots, e.g. "spec.template.spec.containers[0].image"
-// if the field is a slice, the last key must be in the form of "key[index]"
+// path is a list of strings separated by dots, e.g. "spec.template.spec.containers[0].image"
+// If the field is a slice, the last string must be in the form of "field[index]", where index is an integer
+// If the field is a map, the last string must be in the form of "field[key]", where key is a string
 func getNestedString(object interface{}, path []string) (string, bool, error) {
-	re := regexp.MustCompile(`^(.*)\[(\d+|[a-z]+)]$`)
 	var cpath []string
 	for i, key := range path {
-		m := re.FindStringSubmatch(key)
-		if len(m) > 0 {
-			cpath = append(cpath, m[1])
-			slice, found, err := unstructured.NestedSlice(object.(map[string]interface{}), cpath...)
-			if !found || err != nil {
-				return "", false, err
-			}
-			index, err := strconv.Atoi(m[2])
-			if err != nil && m[2] != "last" {
-				return "", false, fmt.Errorf("invalid array index: %s", m[2])
-			}
-			if m[2] == "last" {
-				index = len(slice) - 1
+		if strings.HasPrefix(key, "[") && strings.HasSuffix(key, "]") {
+			k := key[1 : len(key)-1]
+
+			sliceObj, found, err := unstructured.NestedSlice(object.(map[string]interface{}), cpath...)
+			if err == nil && found {
+				index, err := strconv.Atoi(k)
+				if err != nil {
+					return "", false, fmt.Errorf("invalid array index: %s", k)
+				}
+				if index < 0 {
+					index = len(sliceObj) + index
+				}
+				if index >= len(sliceObj) || index < 0 {
+					return "", false, fmt.Errorf("index out of range")
+				}
+				return getNestedString(sliceObj[index], path[i+1:])
 			}
-			if len(slice) <= index {
-				return "", false, fmt.Errorf("index out of range")
+
+			mapObj, found, err := unstructured.NestedMap(object.(map[string]interface{}), cpath...)
+			if err == nil && found {
+				if _, ok := mapObj[k]; !ok {
+					return "", false, fmt.Errorf("key not found: %s", k)
+				}
+				return getNestedString(mapObj[k], path[i+1:])
 			}
-			return getNestedString(slice[index], path[i+1:])
+		} else {
+			cpath = append(cpath, key)
 		}
-		cpath = append(cpath, key)
 	}
 
 	if reflect.TypeOf(object).String() == "string" {
@@ -364,7 +388,15 @@ func getNestedString(object interface{}, path []string) (string, bool, error) {
 		return strconv.FormatBool(boolVal), found, err
 	}
 
-	// TODO: handle additional types?
+	intVal, found, err := unstructured.NestedInt64(object.(map[string]interface{}), path...)
+	if found && err == nil {
+		return strconv.FormatInt(intVal, 10), found, err
+	}
+
+	floatVal, found, err := unstructured.NestedFloat64(object.(map[string]interface{}), path...)
+	if found && err == nil {
+		return strconv.FormatFloat(floatVal, 'g', -1, 64), found, err
+	}
 
 	return "", found, fmt.Errorf("invalid field type")
 }