fix: Added cluster resources support in k8s trigger (argoproj#1323)

* added cluster resources support in k8s trigger

Signed-off-by: daniel-codefresh <daniel.soifer@codefresh.io>
Signed-off-by: Daniel Soifer <daniel.soifer@codefresh.io>

* added Codefresh to USERS.md

Signed-off-by: daniel-codefresh <daniel.soifer@codefresh.io>
Signed-off-by: Daniel Soifer <daniel.soifer@codefresh.io>

Co-authored-by: Derek Wang <whynowy@gmail.com>

USERS.md

@@ -9,6 +9,7 @@ Organizations below are **officially** using Argo Events. Please send a PR with
 1. [BioBox Analytics](https://biobox.io)
 1. [BlackRock](https://www.blackrock.com/)
 1. [Canva](https://www.canva.com/)
+1. [Codefresh](https://codefresh.io/)
 1. [DevSamurai](https://www.devsamurai.com/)
 1. [Fairwinds](https://fairwinds.com/)
 1. [Greenhouse Software](https://www.greenhouse.io/)

sensors/triggers/standard-k8s/standar-k8s.go

@@ -43,6 +43,11 @@ import (
 	"github.com/argoproj/argo-events/sensors/triggers"
 )
 
+var clusterResources = map[string]bool{
+	"namespaces": true,
+	"nodes":   true,
+}
+
 // StandardK8STrigger implements Trigger interface for standard Kubernetes resources
 type StandardK8sTrigger struct {
 	// K8sClient is kubernetes client
@@ -110,8 +115,10 @@ func (k8sTrigger *StandardK8sTrigger) FetchResource(ctx context.Context) (interf
 		if objName == "" {
 			return nil, fmt.Errorf("resource name must be specified for fetching live object")
 		}
+
 		objNamespace := uObj.GetNamespace()
-		if objNamespace == "" {
+		_, isClusterResource := clusterResources[trigger.Template.K8s.GroupVersionResource.Resource]
+		if objNamespace == "" && !isClusterResource {
 			return nil, fmt.Errorf("resource namespace must be specified for fetching live object")
 		}
 		rObj, err = k8sTrigger.namespableDynamicClient.Namespace(objNamespace).Get(ctx, objName, metav1.GetOptions{})
@@ -145,10 +152,13 @@ func (k8sTrigger *StandardK8sTrigger) Execute(ctx context.Context, events map[st
 		return nil, errors.New("failed to interpret the trigger resource")
 	}
 
-	namespace := obj.GetNamespace()
-	// Defaults to sensor's namespace
-	if namespace == "" {
-		namespace = k8sTrigger.Sensor.Namespace
+	namespace := ""
+	if _, isClusterResource := clusterResources[trigger.Template.K8s.GroupVersionResource.Resource]; !isClusterResource {
+		namespace = obj.GetNamespace()
+		// Defaults to sensor's namespace
+		if namespace == "" {
+			namespace = k8sTrigger.Sensor.Namespace
+		}
 	}
 	obj.SetNamespace(namespace)