feat: Add workflow vars for template name and entrypoint

Add two new global workflow variables.
Issue #6772 asks for the template name, but we cannot always know what
this is (simplest unknowable is kubectl apply of a workflow with a
generateName:) So provide that by deduction. See the tests added in
this commit for what we're aiming for there.
Also provide the variable mainEndpoint, which is set to the name of
the invoked entrypoint, which is controllable, knowable, and could be
used in the same way, and seems like a useful thing to have anyway.

Addresses #6772.

Signed-off-by: Alan Clucas <[email protected]>

docs/variables.md

@@ -243,7 +243,9 @@ For `Template`-level metrics:
 | Variable | Description|
 |----------|------------|
 | `workflow.name` | Workflow name |
+| `workflow.templateName` | Workflow template name. This works only for template names, it may give wrong answers for non-generated names |
 | `workflow.namespace` | Workflow namespace |
+| `workflow.main entrypoint` | Workflow's initial entrypoint |
 | `workflow.serviceAccountName` | Workflow service account name |
 | `workflow.uid` | Workflow UID. Useful for setting ownership reference to a resource, or a unique artifact location |
 | `workflow.parameters.<NAME>` | Input parameter to the workflow |

workflow/common/common.go

@@ -165,8 +165,12 @@ const (
 
 	// GlobalVarWorkflowName is a global workflow variable referencing the workflow's metadata.name field
 	GlobalVarWorkflowName = "workflow.name"
+	// GlobalVarWorkflowTemplateName is a global workflow variable referencing the workflow's name reverse engineered to the template name from a generateName
+	GlobalVarWorkflowTemplateName = "workflow.templateName"
 	// GlobalVarWorkflowNamespace is a global workflow variable referencing the workflow's metadata.namespace field
 	GlobalVarWorkflowNamespace = "workflow.namespace"
+	// GlobalVarWorkflowMainEntrypoint is a global workflow variable referencing the workflow's top level entrypoint name
+	GlobalVarWorkflowMainEntrypoint = "workflow.mainEntrypoint"
 	// GlobalVarWorkflowServiceAccountName is a global workflow variable referencing the workflow's spec.serviceAccountName field
 	GlobalVarWorkflowServiceAccountName = "workflow.serviceAccountName"
 	// GlobalVarWorkflowUID is a global workflow variable referencing the workflow's metadata.uid field

workflow/controller/operator.go

@@ -552,10 +552,23 @@ func (woc *wfOperationCtx) getWorkflowDeadline() *time.Time {
 	return &deadline
 }
 
+// templateNameFromName tries to strip the suffix for a cronworkflow [\d]{10} or from a
+// generateName [a-z0-9]{5} from the name.
+var templateNameFromName = regexp.MustCompile(`^(.{3,}?)(\-?[\d]{10})?(\-?[a-z0-9]{5})?$`)
+
+func getTemplateNameFromName(name string) string {
+	if templateNameFromName.MatchString(name) {
+		return templateNameFromName.ReplaceAllString(name, "$1")
+	}
+	return name
+}
+
 // setGlobalParameters sets the globalParam map with global parameters
 func (woc *wfOperationCtx) setGlobalParameters(executionParameters wfv1.Arguments) error {
 	woc.globalParams[common.GlobalVarWorkflowName] = woc.wf.ObjectMeta.Name
+	woc.globalParams[common.GlobalVarWorkflowTemplateName] = getTemplateNameFromName(woc.wf.ObjectMeta.Name)
 	woc.globalParams[common.GlobalVarWorkflowNamespace] = woc.wf.ObjectMeta.Namespace
+	woc.globalParams[common.GlobalVarWorkflowMainEntrypoint] = woc.execWf.Spec.Entrypoint
 	woc.globalParams[common.GlobalVarWorkflowServiceAccountName] = woc.execWf.Spec.ServiceAccountName
 	woc.globalParams[common.GlobalVarWorkflowUID] = string(woc.wf.ObjectMeta.UID)
 	woc.globalParams[common.GlobalVarWorkflowCreationTimestamp] = woc.wf.ObjectMeta.CreationTimestamp.Format(time.RFC3339)

workflow/controller/operator_test.go

@@ -363,6 +363,7 @@ func TestGlobalParams(t *testing.T) {
 
 	assert.Contains(t, woc.globalParams, "workflow.duration")
 	assert.Contains(t, woc.globalParams, "workflow.name")
+	assert.Contains(t, woc.globalParams, "workflow.templateName")
 	assert.Contains(t, woc.globalParams, "workflow.namespace")
 	assert.Contains(t, woc.globalParams, "workflow.parameters")
 	assert.Contains(t, woc.globalParams, "workflow.annotations")
@@ -375,6 +376,22 @@ func TestGlobalParams(t *testing.T) {
 	assert.Contains(t, woc.globalParams, "workflow.labels.workflows.argoproj.io/phase")
 }
 
+func TestTemplateName(t *testing.T) {
+	for input, expected := range map[string]string{
+		`template-name-1234567890`:       `template-name`, // Cronworkflows run on a cron
+		`template-name1234567890`:        `template-name`, // Cronworkflow without trailing -
+		`foobar-fs4hy`:                   `foobar`,        // Standard template submission
+		`foobar-foobar-ashda`:            `foobar-foobar`,
+		`foobarfs4hy`:                    `foobar`, // Template without trailing -
+		`foobar`:                         `foobar`, // We don't replace the end of this
+		`foo-bar`:                        `foo-bar`,
+		`foobar-foobar-0987654321-4ab1a`: `foobar-foobar`, // Cronworkflow, resubmitted
+		`foobar-foobar`:                  `foobar-f`,      // Can't really prevent this kind of thing, not desired though
+	} {
+		assert.Equal(t, expected, getTemplateNameFromName(input))
+	}
+}
+
 // TestSidecarWithVolume verifies ia sidecar can have a volumeMount reference to both existing or volumeClaimTemplate volumes
 func TestSidecarWithVolume(t *testing.T) {
 	wf := wfv1.MustUnmarshalWorkflow(sidecarWithVol)
@@ -6620,7 +6637,7 @@ spec:
     container:
       image: docker/whalesay:latest
       command: [cowsay]
-      args: ["{{workflows.scheduledTime}}"]
+      args: ["{{workflow.scheduledTime}}"]
 `
 
 func TestWorkflowScheduledTimeVariable(t *testing.T) {
@@ -6634,6 +6651,33 @@ func TestWorkflowScheduledTimeVariable(t *testing.T) {
 	assert.Equal(t, "2006-01-02T15:04:05-07:00", woc.globalParams[common.GlobalVarWorkflowCronScheduleTime])
 }
 
+var wfMainEntrypointVariable = `
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: hello-world
+spec:
+  entrypoint: whalesay
+  shutdown: "Stop"
+  templates:
+  - name: whalesay
+    container:
+      image: docker/whalesay:latest
+      command: [cowsay]
+      args: ["{{workflow.mainEntrypoint}}"]
+`
+
+func TestWorkflowMainEntrypointVariable(t *testing.T) {
+	wf := wfv1.MustUnmarshalWorkflow(wfMainEntrypointVariable)
+	cancel, controller := newController(wf)
+	defer cancel()
+
+	ctx := context.Background()
+	woc := newWorkflowOperationCtx(wf, controller)
+	woc.operate(ctx)
+	assert.Equal(t, "whalesay", woc.globalParams[common.GlobalVarWorkflowMainEntrypoint])
+}
+
 var wfNodeNameField = `
 apiVersion: argoproj.io/v1alpha1
 kind: Workflow

workflow/validate/validate.go

@@ -65,7 +65,9 @@ type templateValidationCtx struct {
 func newTemplateValidationCtx(wf *wfv1.Workflow, opts ValidateOpts) *templateValidationCtx {
 	globalParams := make(map[string]string)
 	globalParams[common.GlobalVarWorkflowName] = placeholderGenerator.NextPlaceholder()
+	globalParams[common.GlobalVarWorkflowTemplateName] = placeholderGenerator.NextPlaceholder()
 	globalParams[common.GlobalVarWorkflowNamespace] = placeholderGenerator.NextPlaceholder()
+	globalParams[common.GlobalVarWorkflowMainEntrypoint] = placeholderGenerator.NextPlaceholder()
 	globalParams[common.GlobalVarWorkflowServiceAccountName] = placeholderGenerator.NextPlaceholder()
 	globalParams[common.GlobalVarWorkflowUID] = placeholderGenerator.NextPlaceholder()
 	return &templateValidationCtx{