feat: Include node.name as a field for interpolation (argoproj#9641)

Signed-off-by: Ryan Copley <[email protected]>
Signed-off-by: Ryan Copley <[email protected]>
Co-authored-by: Saravanan Balasubramanian <[email protected]>

Author: RyanCopley

docs/variables.md

@@ -130,6 +130,7 @@ returns `0`. Please review the Sprig documentation to understand which functions
 | `inputs.parameters.<NAME>`| Input parameter to a template |
 | `inputs.parameters`| All input parameters to a template as a JSON string |
 | `inputs.artifacts.<NAME>` | Input artifact to a template |
+| `node.name` | Full name of the node |
 
 ### Steps Templates
 

workflow/controller/operator.go

@@ -1735,6 +1735,9 @@ func (woc *wfOperationCtx) executeTemplate(ctx context.Context, nodeName string,
 	if orgTmpl.IsWorkflowStep() {
 		localParams["steps.name"] = orgTmpl.GetName()
 	}
+
+	localParams["node.name"] = nodeName
+
 	// Merge Template defaults to template
 	err = woc.mergedTemplateDefaultsInto(resolvedTmpl)
 	if err != nil {

workflow/controller/operator_test.go

@@ -6608,6 +6608,58 @@ func TestWorkflowScheduledTimeVariable(t *testing.T) {
 	assert.Equal(t, "2006-01-02T15:04:05-07:00", woc.globalParams[common.GlobalVarWorkflowCronScheduleTime])
 }
 
+var wfNodeNameField = `
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: hello-world
+spec:
+  entrypoint: main
+  templates:
+    - name: main
+      dag:
+        tasks:
+          - name: this-is-part-1
+            template: main2
+    - name: main2
+      steps:
+        - - name: this-is-part-2
+            template: whalesay
+            arguments:
+                parameters:
+                  - name: message
+                    value: "{{node.name}}"
+    - name: whalesay
+      inputs:
+        parameters:
+          - name: message
+      container:
+        image: docker/whalesay:latest
+        command: [cowsay]
+        args: ["{{ inputs.parameters.message }}"]
+`
+
+func TestWorkflowInterpolatesNodeNameField(t *testing.T) {
+	wf := wfv1.MustUnmarshalWorkflow(wfNodeNameField)
+	cancel, controller := newController(wf)
+	defer cancel()
+
+	ctx := context.Background()
+	woc := newWorkflowOperationCtx(wf, controller)
+	woc.operate(ctx)
+
+	foundPod := false
+	for _, element := range woc.wf.Status.Nodes {
+		if element.Type == "Pod" {
+			foundPod = true
+			assert.Equal(t, "hello-world.this-is-part-1", element.Inputs.Parameters[0].Value.String())
+		}
+	}
+
+	assert.True(t, foundPod)
+
+}
+
 func TestWorkflowShutdownStrategy(t *testing.T) {
 	wf := wfv1.MustUnmarshalWorkflow(`
 apiVersion: argoproj.io/v1alpha1

workflow/validate/validate.go

@@ -610,6 +610,7 @@ func resolveAllVariables(scope map[string]interface{}, globalParams map[string]s
 			} else if strings.HasPrefix(tag, common.GlobalVarWorkflowDuration) {
 			} else if strings.HasPrefix(tag, "tasks.name") {
 			} else if strings.HasPrefix(tag, "steps.name") {
+			} else if strings.HasPrefix(tag, "node.name") {
 			} else if strings.HasPrefix(tag, "workflow.parameters") && workflowTemplateValidation {
 				// If we are simply validating a WorkflowTemplate in isolation, some of the parameters may come from the Workflow that uses it
 			} else {

workflow/validate/validate_test.go

@@ -3018,6 +3018,39 @@ func TestInitContainerHasName(t *testing.T) {
 	assert.EqualError(t, err, "templates.main.tasks.spurious initContainers must all have container name")
 }
 
+var nodeNamePlumbsCorrectly = `
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+    generateName: hello-world-
+spec:
+    entrypoint: main
+    templates:
+      - name: main
+        dag:
+          tasks:
+            - name: this-is-part-1
+              template: main2
+      - name: main2
+        steps:
+          - - name: this-is-part-2
+              template: main3
+      - name: main3
+        dag:
+          tasks:
+            - name: this-is-part-3
+              template: whalesay
+      - name: whalesay
+        container:
+          image: docker/whalesay:latest
+          command: [cowsay]
+          args: ["{{ node.name }}"]`
+
+func TestNodeNameParameterInterpoliates(t *testing.T) {
+	err := validate(nodeNamePlumbsCorrectly)
+	assert.NoError(t, err)
+}
+
 func TestSubstituteGlobalVariablesLabelsAnnotations(t *testing.T) {
 	tests := []struct {
 		name             string