Remove hard-coded namespace from k8s config

The default namespace should be populated by the Kubernetes client. In the case
of in-cluster config, the namespace will be read from the
/var/run/secrets/kubernetes.io/serviceaccount/namespace file. (Note that this
assumes the ServiceAccount admission controller is in use.) In the case of
parsing a k8s configuration file, the default namespace is set to the client
default of "default".

Minor spelling correction of Kubernetes and some additional error information
was changed as well.

Closes #5378

CHANGELOG.asciidoc

@@ -42,6 +42,7 @@ https://github.com/elastic/beats/compare/v6.0.0-beta2...master[Check the HEAD di
 - Do not require template if index change and template disabled {pull}5319[5319]
 - Correctly send configured `Host` header to the remote server. {issue}4842[4842]
 - Fix missing ACK in redis output. {issue}5404[5404]
+- Change add_kubernetes_metadata to attempt detection of namespace. {pull}5482[5482]
 
 *Auditbeat*
 

libbeat/processors/add_kubernetes_metadata/config.go

@@ -30,12 +30,11 @@ type Enabled struct {
 
 type PluginConfig []map[string]common.Config
 
-func defaultKuberentesAnnotatorConfig() kubeAnnotatorConfig {
+func defaultKubernetesAnnotatorConfig() kubeAnnotatorConfig {
 	return kubeAnnotatorConfig{
 		InCluster:       true,
 		SyncPeriod:      1 * time.Second,
 		CleanupTimeout:  60 * time.Second,
-		Namespace:       "kube-system",
 		DefaultMatchers: Enabled{true},
 		DefaultIndexers: Enabled{true},
 	}

libbeat/processors/add_kubernetes_metadata/kubernetes.go

@@ -44,7 +44,7 @@ func init() {
 func newKubernetesAnnotator(cfg *common.Config) (processors.Processor, error) {
 	cfgwarn.Beta("The kubernetes processor is beta")
 
-	config := defaultKuberentesAnnotatorConfig()
+	config := defaultKubernetesAnnotatorConfig()
 
 	err := cfg.Unpack(&config)
 	if err != nil {
@@ -87,7 +87,7 @@ func newKubernetesAnnotator(cfg *common.Config) (processors.Processor, error) {
 	if config.InCluster == true {
 		client, err = k8s.NewInClusterClient()
 		if err != nil {
-			return nil, fmt.Errorf("Unable to get in cluster configuration")
+			return nil, fmt.Errorf("Unable to get in cluster configuration: %v", err)
 		}
 	} else {
 		data, err := ioutil.ReadFile(config.KubeConfig)
@@ -109,11 +109,11 @@ func newKubernetesAnnotator(cfg *common.Config) (processors.Processor, error) {
 	ctx := context.Background()
 	if config.Host == "" {
 		podName := os.Getenv("HOSTNAME")
-		logp.Info("Using pod name %s and namespace %s", podName, config.Namespace)
+		logp.Info("Using pod name %s and namespace %s", podName, client.Namespace)
 		if podName == "localhost" {
 			config.Host = "localhost"
 		} else {
-			pod, error := client.CoreV1().GetPod(ctx, podName, config.Namespace)
+			pod, error := client.CoreV1().GetPod(ctx, podName, client.Namespace)
 			if error != nil {
 				logp.Err("Querying for pod failed with error: ", error.Error())
 				logp.Info("Unable to find pod, setting host to localhost")