Fix for Resource creation where template has same parameter templating

test/e2e/functional/custom_template_variable.yaml

@@ -0,0 +1,32 @@
+# This template demonstrates the customer variable suppport.
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  generateName: custom-template-variable-
+spec:
+  entrypoint: hello-hello-hello
+
+  templates:
+    - name: hello-hello-hello
+      steps:
+        - - name: hello1
+            template: whalesay
+            arguments:
+              parameters: [{name: message, value: "hello1"}]
+        - - name: hello2a
+            template: whalesay
+            arguments:
+              parameters: [{name: message, value: "hello2a"}]
+          - name: hello2b
+            template: whalesay
+            arguments:
+              parameters: [{name: message, value: "hello2b"}]
+
+    - name: whalesay
+      inputs:
+        parameters:
+          - name: message
+      container:
+        image: docker/whalesay
+        command: [cowsay]
+        args: ["{{custom.variable}}"]

workflow/common/common.go

@@ -115,6 +115,9 @@ const (
 	KubeConfigDefaultVolumeName = "kubeconfig"
 )
 
+// GlobalVarWorkflowRootTags is a list of root tags in workflow which could be used for variable reference
+var GlobalVarValidWorkflowVariablePrefix = [6]string{"item", "steps", "inputs", "outputs", "workflow", "tasks"}
+
 // ExecutionControl contains execution control parameters for executor to decide how to execute the container
 type ExecutionControl struct {
 	// Deadline is a max timestamp in which an executor can run the container before terminating it

workflow/validate/validate.go

@@ -230,6 +230,11 @@ func resolveAllVariables(scope map[string]interface{}, tmplStr string) error {
 	fstTmpl := fasttemplate.New(tmplStr, "{{", "}}")
 
 	fstTmpl.ExecuteFuncString(func(w io.Writer, tag string) (int, error) {
+
+		// Skip the custom variable references
+		if !checkValidWorkflowVariablePrefix(tag) {
+			return 0, nil
+		}
 		_, ok := scope[tag]
 		if !ok && unresolvedErr == nil {
 			if (tag == "item" || strings.HasPrefix(tag, "item.")) && allowAllItemRefs {
@@ -245,6 +250,16 @@ func resolveAllVariables(scope map[string]interface{}, tmplStr string) error {
 	return unresolvedErr
 }
 
+// checkValidWorkflowVariablePrefix is a helper methood check variable starts workflow root elements
+func checkValidWorkflowVariablePrefix(tag string) bool {
+	for _, rootTag := range common.GlobalVarValidWorkflowVariablePrefix {
+		if strings.HasPrefix(tag, rootTag) {
+			return true
+		}
+	}
+	return false
+}
+
 func validateNonLeaf(tmpl *wfv1.Template) error {
 	if tmpl.ActiveDeadlineSeconds != nil {
 		return errors.Errorf(errors.CodeBadRequest, "templates.%s.activeDeadlineSeconds is only valid for leaf templates", tmpl.Name)