Query namespaced resources in current namespace by default (#22)

* Add a flag --all-namespaces

* Document

* No global variables anymore

* Fixes

* remove unused allNs

Author: feloy

README.md

@@ -24,6 +24,14 @@ Example (Agones Fleet):
 
 ![example Kubernetes object hierarchy with Agones Fleet](assets/example-3.png)
 
+## Flags
+
+By default, the plugin will only search "namespaced" objects in the same
+namespace as the specified object.
+
+You can use the `-A` or `--all-namespaces` flag to search namespaced and
+non-namespaced objects in all namespaces.
+
 ## Author
 
 Ahmet Alp Balkan [@ahmetb](https://twitter.com/ahmetb).

cmd/kubectl-tree/apis.go

@@ -67,7 +67,6 @@ func findAPIs(client discovery.DiscoveryInterface) (*resourceMap, error) {
 				klog.V(4).Infof("    api (%s) doesn't have required verb, skipping: %v", apiRes.Name, apiRes.Verbs)
 				continue
 			}
-
 			v := apiResource{
 				gv: gv,
 				r:  apiRes,
@@ -80,6 +79,7 @@ func findAPIs(client discovery.DiscoveryInterface) (*resourceMap, error) {
 			rm.list = append(rm.list, v)
 		}
 	}
+	klog.V(5).Infof("  found %d apis", len(rm.m))
 	return rm, nil
 }
 

cmd/kubectl-tree/namespace.go

@@ -0,0 +1,13 @@
+package main
+
+func getNamespace() string {
+	if v := *cf.Namespace; v != "" {
+		return v
+	}
+	clientConfig := cf.ToRawKubeConfigLoader()
+	defaultNamespace, _, err := clientConfig.Namespace()
+	if err != nil {
+		defaultNamespace = "default"
+	}
+	return defaultNamespace
+}

cmd/kubectl-tree/query.go

@@ -12,7 +12,7 @@ import (
 )
 
 // getAllResources finds all API objects in specified API resources in all namespaces (or non-namespaced).
-func getAllResources(client dynamic.Interface, apis []apiResource) ([]unstructured.Unstructured, error) {
+func getAllResources(client dynamic.Interface, apis []apiResource, allNs bool) ([]unstructured.Unstructured, error) {
 	var mu sync.Mutex
 	var wg sync.WaitGroup
 	var out []unstructured.Unstructured
@@ -22,11 +22,15 @@ func getAllResources(client dynamic.Interface, apis []apiResource) ([]unstructur
 
 	var errResult error
 	for _, api := range apis {
+		if !allNs && !api.r.Namespaced {
+			klog.V(4).Infof("[query api] api (%s) is non-namespaced, skipping", api.r.Name)
+			continue
+		}
 		wg.Add(1)
 		go func(a apiResource) {
 			defer wg.Done()
 			klog.V(4).Infof("[query api] start: %s", a.GroupVersionResource())
-			v, err := queryAPI(client, a)
+			v, err := queryAPI(client, a, allNs)
 			if err != nil {
 				klog.V(4).Infof("[query api] error querying: %s, error=%v", a.GroupVersionResource(), err)
 				errResult = err
@@ -46,12 +50,24 @@ func getAllResources(client dynamic.Interface, apis []apiResource) ([]unstructur
 	return out, errResult
 }
 
-func queryAPI(client dynamic.Interface, api apiResource) ([]unstructured.Unstructured, error) {
+func queryAPI(client dynamic.Interface, api apiResource, allNs bool) ([]unstructured.Unstructured, error) {
 	var out []unstructured.Unstructured
 
 	var next string
+	var ns string
+
+	if !allNs {
+		ns = getNamespace()
+	}
 	for {
-		resp, err := client.Resource(api.GroupVersionResource()).List(metav1.ListOptions{
+		var intf dynamic.ResourceInterface
+		nintf := client.Resource(api.GroupVersionResource())
+		if !allNs {
+			intf = nintf.Namespace(ns)
+		} else {
+			intf = nintf
+		}
+		resp, err := intf.List(metav1.ListOptions{
 			Limit:    250,
 			Continue: next,
 		})

cmd/kubectl-tree/rootcmd.go

@@ -30,6 +30,10 @@ import (
 	"k8s.io/klog"
 )
 
+const (
+	allNamespacesFlag = "all-namespaces"
+)
+
 var cf *genericclioptions.ConfigFlags
 
 // This variable is populated by goreleaser
@@ -57,7 +61,13 @@ func versionString() string {
 	return "v" + version
 }
 
-func run(_ *cobra.Command, args []string) error {
+func run(command *cobra.Command, args []string) error {
+
+	allNs, err := command.Flags().GetBool(allNamespacesFlag)
+	if err != nil {
+		allNs = false
+	}
+
 	restConfig, err := cf.ToRESTConfig()
 	if err != nil {
 		return err
@@ -102,15 +112,8 @@ func run(_ *cobra.Command, args []string) error {
 		api = apiResults[0]
 	}
 
-	ns := *cf.Namespace
-	if ns == "" {
-		clientConfig := cf.ToRawKubeConfigLoader()
-		defaultNamespace, _, err := clientConfig.Namespace()
-		if err != nil {
-			defaultNamespace = "default"
-		}
-		ns = defaultNamespace
-	}
+	ns := getNamespace()
+	klog.V(2).Infof("namespace=%s allNamespaces=%v", ns, allNs)
 
 	obj, err := dyn.Resource(api.GroupVersionResource()).Namespace(ns).Get(name, metav1.GetOptions{})
 	if err != nil {
@@ -120,7 +123,7 @@ func run(_ *cobra.Command, args []string) error {
 	klog.V(5).Infof("target parent object: %#v", obj)
 
 	klog.V(2).Infof("querying all api objects")
-	apiObjects, err := getAllResources(dyn, apis.resources())
+	apiObjects, err := getAllResources(dyn, apis.resources(), allNs)
 	if err != nil {
 		return fmt.Errorf("error while querying api objects: %w", err)
 	}
@@ -148,6 +151,9 @@ func init() {
 	})
 
 	cf = genericclioptions.NewConfigFlags(true)
+
+	rootCmd.Flags().BoolP(allNamespacesFlag, "A", false, "query all objects in all API groups, both namespaced and non-namespaced")
+
 	cf.AddFlags(rootCmd.Flags())
 	if err := flag.Set("logtostderr", "true"); err != nil {
 		fmt.Fprintf(os.Stderr, "failed to set logtostderr flag: %v\n", err)