fix: Skip execution control for agent pod during pod reconciliation. Fixes #12726

[jswxstw]

Fixes #12726

Motivation

Obtain nonexistent node with agent pod in applyExecutionControl.

Modifications

Skip execution control for agent pod during pod reconciliation, it will be done here now:

argo-workflows/workflow/controller/operator.go

Lines 312 to 315 in 735739f

	// Execution control has been applied to the nodes with created pods after pod reconciliation.
	// However, pending and suspended nodes do not have created pods, and taskset nodes use the agent pod.
	// Apply execution control to these nodes now since pod reconciliation does not take effect on them.
	woc.failNodesWithoutCreatedPodsAfterDeadlineOrShutdown()

Verification

local test

[Joibel]

LGTM.

Looks like the test failures are the common ones which have been happening recently.

[jswxstw]

LGTM.

Looks like the test failures are the common ones which have been happening recently.

Related to: #12730 (comment)

[agilgur5]

/retest

Hmm that might have failed because the job run is 2 months old. I didn't have a button to rerun the job either in the UI.

To trigger a re-run I updated the branch via the button on the GH UI, selected rebase instead of merge, annnd it broke DCO 😕

[agilgur5]

I'm wondering if this has a use-case for Agent pods -- the Workflow's deadline should still apply to them.

woc.wf.NodeId("agent") seems to work for them in agent.go's getAgentPodName() func

[jswxstw]

To trigger a re-run I updated the branch via the button on the GH UI, selected rebase instead of merge, annnd it broke DCO

I fixed it, but there are some new failed tests that appear frequently recently.

I'm wondering if this has a use-case for Agent pods -- the Workflow's deadline should still apply to them.

I've also thought about it. The workflow's deadline can not apply to agent pods since they do not support being terminated now.

This is somewhat related to another issue I raised, see #12692 (comment).

[agilgur5]

I've also thought about it. The workflow's deadline can not apply to agent pods since they do not support being terminated now.

This is somewhat related to another issue I raised, see #12692 (comment).

Ah I see, because it doesn't support the kill command etc (which is pretty hacky as-is). Could you leave a TODO comment above this line then, e.g. // TODO: run for Agent Pod as well once it supports termination by the Controller?

Also when you've thought through some of these situations, it's useful to write them down in the PR description, both for historical context and so that reviewers know without even asking. I use a "### Notes to Reviewers" section in my PRs where there are some changes that require an explanation

Also just wanted to say, I do appreciate all the investigation and work you've done for the Agent and Plugins!

[agilgur5]

I fixed it, but there are some new failed tests that appear frequently recently.

Yea these seem to have been really recent, I only noticed them earlier today. I'm not sure which PR caused them though from a look through of the commit history on main 😕 Seem to have happened at least two days ago though per #13002's test run

[jswxstw]

Ah I see, because it doesn't support the kill command etc (which is pretty hacky as-is). Could you leave a TODO comment above this line then, e.g. // TODO: run for Agent Pod as well once it supports termination by the Controller?

The agent pod will be deleted once the workflow is completed now, so the pod termination may be unnecessary.

This PR #12441 has support plugin nodes shutdown, but there are a few unresolved issues.

argo-workflows/workflow/controller/operator.go

Lines 1265 to 1282 in ccb71bd

	func (woc *wfOperationCtx) failSuspendedAndPendingNodesAfterDeadlineOrShutdown() {
	for _, node := range woc.wf.Status.Nodes {
	// fail suspended nodes or plugin nodes when shuting down
	if woc.GetShutdownStrategy().Enabled() && (node.IsActiveSuspendNode() || node.IsActivePluginNode()) {
	message := fmt.Sprintf("Stopped with strategy '%s'", woc.GetShutdownStrategy())
	woc.markNodePhase(node.Name, wfv1.NodeFailed, message)
	continue
	}
	// fail all pending and suspended nodes when exceeding deadline
	deadlineExceeded := woc.workflowDeadline != nil && time.Now().UTC().After(*woc.workflowDeadline)
	if deadlineExceeded && (node.Phase == wfv1.NodePending || node.IsActiveSuspendNode()) {
	message := "Step exceeded its deadline"
	woc.markNodePhase(node.Name, wfv1.NodeFailed, message)
	continue
	}
	}
	}

1. Active HTTP nodes should also be shut down here since they also use the agent pod.
2. The workflow's deadline should also apply to all active taskset nodes(HTTP/Plugin) here.

I will submit a new PR to fix it. EDIT: See #13016

[agilgur5]

The agent pod will be deleted once the workflow is completed now, so the pod termination may be unnecessary.

For now I suppose. It's a little bit different timing-wise, but close enough. A comment would still be helpful as it is relevant to #12692 / must change if that is implemented

1. Active HTTP nodes should also be shut down here since they also use the agent pod.

Agreed

2. The workflow's ttl should also apply to all active taskset nodes(HTTP/Plugin) here.

How is TTL related there? Since it's only deadline related

[jswxstw]

How is TTL related there? Since it's only deadline related

Sorry, I made a mistake and I actually meant the workflow's deadline.
I actually want to say that it is reasonable to skip execution control in applyExecutionControl for the agent pod since it will or should be done in failSuspendedAndPendingNodesAfterDeadlineOrShutdown.
EDIT: See #13016

[jswxstw]

@agilgur5 Can this PR be merged?

[agilgur5]

Could you leave a TODO comment above this line then, e.g. // TODO: run for Agent Pod as well once it supports termination by the Controller?

A comment would still be helpful as it is relevant to #12692 / must change if that is implemented

This was the only thing I was waiting for. Has actually been on my to-do list to add this myself since I have that permission these days

[jswxstw]

This was the only thing I was waiting for. Has actually been on my to-do list to add this myself since I have that permission these days

I updated the PR information, execution control will apply for nodes of the agent pod here now:

argo-workflows/workflow/controller/operator.go

Lines 312 to 315 in 735739f

	// Execution control has been applied to the nodes with created pods after pod reconciliation.
	// However, pending and suspended nodes do not have created pods, and taskset nodes use the agent pod.
	// Apply execution control to these nodes now since pod reconciliation does not take effect on them.
	woc.failNodesWithoutCreatedPodsAfterDeadlineOrShutdown()