Expose all input parameters to template as JSON

docs/variables.md

@@ -6,6 +6,7 @@ The following variables are made available to reference various metadata of a wo
 | Variable | Description|
 |----------|------------|
 | `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 |
 
 ## Steps Templates:

workflow/common/util.go

@@ -325,6 +325,12 @@ func substituteParams(tmpl *wfv1.Template, globalParams, localParams map[string]
 		}
 		replaceMap["inputs.parameters."+inParam.Name] = *inParam.Value
 	}
+	//allow {{inputs.parameters}} to fetch the entire input parameters list as JSON
+	jsonInputParametersBytes, err := json.Marshal(globalReplacedTmpl.Inputs.Parameters)
+	if err != nil {
+		return nil, errors.InternalWrapError(err)
+	}
+	replaceMap["inputs.parameters"] = string(jsonInputParametersBytes)
 	for _, inArt := range globalReplacedTmpl.Inputs.Artifacts {
 		if inArt.Path != "" {
 			replaceMap["inputs.artifacts."+inArt.Name+".path"] = inArt.Path
@@ -356,8 +362,7 @@ func substituteParams(tmpl *wfv1.Template, globalParams, localParams map[string]
 
 // Replace executes basic string substitution of a template with replacement values.
 // allowUnresolved indicates whether or not it is acceptable to have unresolved variables
-// remaining in the substituted template. prefixFilter will apply the replacements only
-// to variables with the specified prefix
+// remaining in the substituted template.
 func Replace(fstTmpl *fasttemplate.Template, replaceMap map[string]string, allowUnresolved bool) (string, error) {
 	var unresolvedErr error
 	replacedTmpl := fstTmpl.ExecuteFuncString(func(w io.Writer, tag string) (int, error) {

workflow/controller/operator_test.go

@@ -504,6 +504,64 @@ func TestSuspendResume(t *testing.T) {
 	assert.Equal(t, 2, len(pods.Items))
 }
 
+var inputParametersAsJson = `
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: whalesay
+spec:
+  entrypoint: steps
+  arguments:
+    parameters:
+    - name: parameter1
+      value: value1
+    - name: parameter2
+      value: value2
+  templates:
+  - name: steps
+    inputs:
+      parameters:
+      - name: parameter1
+      - name: parameter2
+    steps:
+      - - name: step1
+          template: whalesay
+          arguments:
+            parameters:
+            - name: json
+              value: "{{inputs.parameters}}"
+
+  - name: whalesay
+    inputs:
+      parameters:
+      - name: json
+    container:
+      image: docker/whalesay:latest
+      command: [cowsay]
+`
+
+func TestInputParametersAsJson(t *testing.T) {
+	controller := newController()
+	wfcset := controller.wfclientset.ArgoprojV1alpha1().Workflows("")
+
+	wf := unmarshalWF(inputParametersAsJson)
+	wf, err := wfcset.Create(wf)
+	assert.Nil(t, err)
+	woc := newWorkflowOperationCtx(wf, controller)
+	woc.operate()
+	updatedWf, err := wfcset.Get(wf.Name, metav1.GetOptions{})
+	assert.Nil(t, err)
+	found := false
+	for _, node := range updatedWf.Status.Nodes {
+		if node.Type == wfv1.NodeTypePod {
+			expectedJson := `[{"name":"parameter1","value":"value1"},{"name":"parameter2","value":"value2"}]`
+			assert.Equal(t, expectedJson, *node.Inputs.Parameters[0].Value)
+			found = true
+		}
+	}
+	assert.Equal(t, true, found)
+}
+
 var expandWithItems = `
 apiVersion: argoproj.io/v1alpha1
 kind: Workflow

workflow/validate/validate.go

@@ -213,6 +213,9 @@ func validateInputs(tmpl *wfv1.Template) (map[string]interface{}, error) {
 	for _, param := range tmpl.Inputs.Parameters {
 		scope[fmt.Sprintf("inputs.parameters.%s", param.Name)] = true
 	}
+	if len(tmpl.Inputs.Parameters) > 0 {
+		scope["inputs.parameters"] = true
+	}
 
 	for _, art := range tmpl.Inputs.Artifacts {
 		artRef := fmt.Sprintf("inputs.artifacts.%s", art.Name)