fix: ensure that nodes complete when workflow fails with parallelism and failFast. Fixes #13806

test/e2e/expectedfailures/parallelism-dag-fail-fast.yaml

@@ -0,0 +1,26 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: parallelism-dag-fail-fast
+spec:
+  entrypoint: main
+  templates:
+    - name: main
+      parallelism: 2
+      failFast: true
+      dag:
+        tasks:
+          - name: task1
+            template: fail
+          - name: task2
+            template: sleep
+    - name: fail
+      container:
+        image: alpine:latest
+        command: [ sh, -c ]
+        args: ["exit 1"]
+    - name: sleep
+      container:
+        image: alpine:latest
+        command: [sh, -c]
+        args: ["sleep 5"]

test/e2e/expectedfailures/parallelism-step-fail-fast.yaml

@@ -0,0 +1,25 @@
+apiVersion: argoproj.io/v1alpha1
+kind: Workflow
+metadata:
+  name: parallelism-step-fail-fast
+spec:
+  entrypoint: main
+  templates:
+    - name: main
+      parallelism: 2
+      failFast: true
+      steps:
+        - - name: step1
+            template: fail
+          - name: step2
+            template: sleep
+    - name: fail
+      container:
+        image: alpine:latest
+        command: [sh, -c]
+        args: ["exit 1"]
+    - name: sleep
+      container:
+        image: alpine:latest
+        command: [ sh, -c ]
+        args: [ "sleep 5" ]

test/e2e/functional_test.go

@@ -1415,3 +1415,34 @@ func (s *FunctionalSuite) TestWorkflowExitHandlerCrashEnsureNodeIsPresent() {
 			assert.NotNil(t, hookNode.Inputs.Parameters[0].Value)
 		})
 }
+
+func (s *FunctionalSuite) TestWorkflowParallelismStepFailFast() {
+	s.Given().
+		Workflow("@expectedfailures/parallelism-step-fail-fast.yaml").
+		When().
+		SubmitWorkflow().
+		WaitForWorkflow(fixtures.ToBeRunning).
+		WaitForWorkflow(fixtures.ToBeFailed).
+		Then().
+		ExpectWorkflow(func(t *testing.T, metadata *v1.ObjectMeta, status *wfv1.WorkflowStatus) {
+			assert.Equal(t, "template has failed or errored children and failFast enabled", status.Message)
+			assert.Equal(t, wfv1.NodeFailed, status.Nodes.FindByDisplayName("[0]").Phase)
+			assert.Equal(t, wfv1.NodeFailed, status.Nodes.FindByDisplayName("step1").Phase)
+			assert.Equal(t, wfv1.NodeSucceeded, status.Nodes.FindByDisplayName("step2").Phase)
+		})
+}
+
+func (s *FunctionalSuite) TestWorkflowParallelismDAGFailFast() {
+	s.Given().
+		Workflow("@expectedfailures/parallelism-dag-fail-fast.yaml").
+		When().
+		SubmitWorkflow().
+		WaitForWorkflow(fixtures.ToBeRunning).
+		WaitForWorkflow(fixtures.ToBeFailed).
+		Then().
+		ExpectWorkflow(func(t *testing.T, metadata *v1.ObjectMeta, status *wfv1.WorkflowStatus) {
+			assert.Equal(t, "template has failed or errored children and failFast enabled", status.Message)
+			assert.Equal(t, wfv1.NodeFailed, status.Nodes.FindByDisplayName("task1").Phase)
+			assert.Equal(t, wfv1.NodeSucceeded, status.Nodes.FindByDisplayName("task2").Phase)
+		})
+}

workflow/controller/operator.go

@@ -2770,6 +2770,26 @@ func (woc *wfOperationCtx) markNodeWaitingForLock(nodeName string, lockName stri
 	return node, nil
 }
 
+func (woc *wfOperationCtx) findLeafNodeWithType(boundaryID string, nodeType wfv1.NodeType) *wfv1.NodeStatus {
+	var leafNode *wfv1.NodeStatus
+	var dfs func(nodeID string)
+	dfs = func(nodeID string) {
+		node, err := woc.wf.Status.Nodes.Get(nodeID)
+		if err != nil {
+			woc.log.Errorf("was unable to obtain node for %s", nodeID)
+			return
+		}
+		if node.Type == nodeType {
+			leafNode = node
+		}
+		for _, childID := range node.Children {
+			dfs(childID)
+		}
+	}
+	dfs(boundaryID)
+	return leafNode
+}
+
 // checkParallelism checks if the given template is able to be executed, considering the current active pods and workflow/template parallelism
 func (woc *wfOperationCtx) checkParallelism(tmpl *wfv1.Template, node *wfv1.NodeStatus, boundaryID string) error {
 	if woc.execWf.Spec.Parallelism != nil && woc.activePods >= *woc.execWf.Spec.Parallelism {
@@ -2781,7 +2801,14 @@ func (woc *wfOperationCtx) checkParallelism(tmpl *wfv1.Template, node *wfv1.Node
 	if node != nil && (tmpl.GetType() == wfv1.TemplateTypeDAG || tmpl.GetType() == wfv1.TemplateTypeSteps) {
 		// Check failFast
 		if tmpl.IsFailFast() && woc.getUnsuccessfulChildren(node.ID) > 0 {
-			woc.markNodePhase(node.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+			if woc.getActivePods(node.ID) == 0 {
+				if tmpl.GetType() == wfv1.TemplateTypeSteps {
+					if leafStepGroupNode := woc.findLeafNodeWithType(node.ID, wfv1.NodeTypeStepGroup); leafStepGroupNode != nil {
+						woc.markNodePhase(leafStepGroupNode.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+					}
+				}
+				woc.markNodePhase(node.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+			}
 			return ErrParallelismReached
 		}
 
@@ -2792,7 +2819,7 @@ func (woc *wfOperationCtx) checkParallelism(tmpl *wfv1.Template, node *wfv1.Node
 		}
 	}
 
-	// if we are about to execute a pod, make sure our parent hasn't reached it's limit
+	// if we are about to execute a pod, make sure our parent hasn't reached its limit
 	if boundaryID != "" && (node == nil || (node.Phase != wfv1.NodePending && node.Phase != wfv1.NodeRunning)) {
 		boundaryNode, err := woc.wf.Status.Nodes.Get(boundaryID)
 		if err != nil {
@@ -2810,7 +2837,14 @@ func (woc *wfOperationCtx) checkParallelism(tmpl *wfv1.Template, node *wfv1.Node
 
 		// Check failFast
 		if boundaryTemplate.IsFailFast() && woc.getUnsuccessfulChildren(boundaryID) > 0 {
-			woc.markNodePhase(boundaryNode.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+			if woc.getActivePods(boundaryID) == 0 {
+				if boundaryTemplate.GetType() == wfv1.TemplateTypeSteps {
+					if leafStepGroupNode := woc.findLeafNodeWithType(boundaryID, wfv1.NodeTypeStepGroup); leafStepGroupNode != nil {
+						woc.markNodePhase(leafStepGroupNode.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+					}
+				}
+				woc.markNodePhase(boundaryNode.Name, wfv1.NodeFailed, "template has failed or errored children and failFast enabled")
+			}
 			return ErrParallelismReached
 		}