fix(backend): pass correct ParentDagID to iterator DAG

- Passthrough ParentDagID rather than DriverExecutionID to iterator such
  that iteration item correctly detects dependentTasks.
- Remove depends from iterator DAG as it is already handled by
  root-level task
- Update Iterator template names/nomenclature for clarity
- Update tests accordingly

Signed-off-by: Giulio Frasca <[email protected]>

backend/src/v2/compiler/argocompiler/dag.go

@@ -274,10 +274,9 @@ func (c *workflowCompiler) iteratorTask(name string, task *pipelinespec.Pipeline
 	// Set up Loop Control Template
 	loopDriverArgoName := name + "-loop-driver"
 	loopDriverInputs := dagDriverInputs{
-		component:      componentSpecPlaceholder,
-		parentDagID:    parentDagID,
-		task:           taskJson, // TODO(Bobgy): avoid duplicating task JSON twice in the template.
-		iterationIndex: "0",
+		component:   componentSpecPlaceholder,
+		parentDagID: parentDagID,
+		task:        taskJson, // TODO(Bobgy): avoid duplicating task JSON twice in the template.
 	}
 	loopDriver, loopDriverOutputs, err := c.dagDriverTask(loopDriverArgoName, loopDriverInputs)
 	if err != nil {
@@ -305,7 +304,7 @@ func (c *workflowCompiler) iteratorTask(name string, task *pipelinespec.Pipeline
 		loopTmpl.Parallelism = &parallellism_limit
 	}
 
-	loopTmplName, err := c.addTemplate(loopTmpl, componentName+"-loop-"+name)
+	loopTmplName, err := c.addTemplate(loopTmpl, fmt.Sprintf("%s-loop-iterator", componentName))
 	if err != nil {
 		return nil, err
 	}
@@ -325,7 +324,7 @@ func (c *workflowCompiler) iteratorTask(name string, task *pipelinespec.Pipeline
 				Parameters: []wfapi.Parameter{
 					{
 						Name:  paramParentDagID,
-						Value: wfapi.AnyStringPtr(loopDriverOutputs.executionID),
+						Value: wfapi.AnyStringPtr(parentDagID),
 					},
 				},
 			},
@@ -382,7 +381,7 @@ func (c *workflowCompiler) iterationItemTask(name string, task *pipelinespec.Pip
 			Tasks: iterationTasks,
 		},
 	}
-	iterationsTmplName, err := c.addTemplate(iterationsTmpl, componentName+"-"+name)
+	iterationsTmplName, err := c.addTemplate(iterationsTmpl, componentName+"-iteration")
 	if err != nil {
 		return nil, err
 	}