When running `kubectl drain` in dry-run, list warnings and pods that would be deleted. #82660

sallyom · 2019-09-12T19:08:29Z

What type of PR is this?

/kind cleanup

What this PR does / why we need it:
This PR will result in listing pods that would be deleted if running kubectl drain <node> along with any warnings or errors that would occur if not in dry-run.

Which issue(s) this PR fixes:

Fixes #
kubernetes/kubectl#719

Does this PR introduce a user-facing change?:

kubectl drain node --dry-run will list pods that would be evicted or deleted

Additional documentation e.g., KEPs (Kubernetes Enhancement Proposals), usage docs, etc.:

k8s-ci-robot · 2019-09-12T19:08:36Z

Hi @sallyom. Thanks for your PR.

I'm waiting for a kubernetes member to verify that this patch is reasonable to test. If it is, they should reply with /ok-to-test on its own line. Until that is done, I will not automatically test new commits in this PR, but the usual testing commands by org members will still work. Regular contributors should join the org to skip this step.

Once the patch is verified, the new status will be reflected by the ok-to-test label.

I understand the commands that are listed here.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

sallyom · 2019-09-12T19:08:55Z

/assign @soltysh

sallyom · 2019-09-13T12:42:18Z

/ok-to-test

:)

sallyom · 2019-09-13T18:44:35Z

sample output:

$ kubectl drain ip-10-0-138-243.blah --dry-run
node/ip-10-0-138-243.blah cordoned (dry run)
evicting pod ns1/pod1
evicting pod ns2/pod2
evicting pod ns3/pod3
evicting pod ns1/pod2
node/ip-10-0-138-243.blah drained (dry run)

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

soltysh · 2019-10-14T18:58:49Z

/priority important-longtemr

k8s-ci-robot · 2019-10-14T18:58:50Z

@soltysh: The label(s) priority/important-longtemr cannot be applied. These labels are supported: api-review, community/discussion, community/maintenance, community/question, cuj/build-train-deploy, cuj/multi-user, platform/aws, platform/azure, platform/gcp, platform/minikube, platform/other

In response to this:

/priority important-longtemr

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository.

soltysh · 2019-10-14T18:58:57Z

/priority important-longterm

sallyom · 2019-10-15T00:25:38Z

/retest

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

sallyom · 2019-10-23T20:13:57Z

/retest

sallyom · 2019-10-23T22:03:17Z

/test pull-kubernetes-node-e2e-containerd

sallyom · 2019-10-24T01:55:41Z

/test pull-kubernetes-node-e2e-containerd

soltysh · 2019-11-27T14:36:52Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

+	if len(list.Pods()) > 0 && o.drainer.DryRun {
+		fmt.Fprintf(o.Out, "namespace/pod (dry run)\n")
+		for _, pod := range list.Pods() {
+			fmt.Fprintf(o.Out, "%s/%s\n", pod.Namespace, pod.Name)


From what I see DeleteOrEvicPods is doing this:

kubernetes/staging/src/k8s.io/kubectl/pkg/drain/drain.go

Line 211 in ab0bfb3

fmt.Fprintf(d.Out, "evicting pod %q\n", pod.Name)

so I'd expect something similar for printing here maybe with (dry run) added at the end.

Although we should probably update that to print both namespace and name altogether, in which case what you have here would be in sync.

Honestly, in both cases, we should probably fix that helper method to be reusable by passing ResourcePrinter but let's leave that as a separate PR 😉

I added namespace to kubectl/pkg/drain/drain.go added "evicting pod ... (dry-run)" to dry-run list.

$ kubectl drain ip-10-0-144-193.us-east-2.compute.internal --dry-run --pod-selector="app=hello-node" node/ip-10-0-144-193.us-east-2.compute.internal cordoned (dry run) evicting pod test/hello-node-7676b5fb8d-6w57 (dry run) node/ip-10-0-144-193.us-east-2.compute.internal drained (dry run)

non-dry-run:

$ kubectl drain ip-10-0-144-193.us-east-2.compute.internal --pod-selector="app=hello-node" node/ip-10-0-144-193.us-east-2.compute.internal cordoned evicting pod test/hello-node-7676b5fb8d-6w57 pod/hello-node-7676b5fb8d-6w57r evicted node/ip-10-0-144-193.us-east-2.compute.internal evicted

also, I changed '%q' to '%s' for printing, so instead of

evicting pod "test"/"hello-node-7676b5fb8d-6w57r" pod/hello-node-7676b5fb8d-6w57r evicted

it prints

evicting pod test/hello-node-7676b5fb8d-6w57r pod/hello-node-7676b5fb8d-6w57r evicted

but will change to %q if that's preferred

soltysh · 2019-11-27T14:37:24Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

@@ -321,12 +319,21 @@ func (o *DrainCmdOptions) RunDrain() error {

 func (o *DrainCmdOptions) deleteOrEvictPodsSimple(nodeInfo *resource.Info) error {
 	list, errs := o.drainer.GetPodsForDeletion(nodeInfo.Name)
+	if len(list.Pods()) > 0 && o.drainer.DryRun {
+		fmt.Fprintf(o.Out, "namespace/pod (dry run)\n")


Remove this line entirely, you'll not gonna get it in regular drain execution path, so it can't be here either.

got it, removed

soltysh · 2019-11-27T14:38:01Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

+		for _, pod := range list.Pods() {
+			fmt.Fprintf(o.Out, "%s/%s\n", pod.Namespace, pod.Name)
+		}
+	}


This entire if should be after the below error check, in the normal when you encounter an error we'll return that error, same applies for dry-run.

ah right, doh, thanks, updated

soltysh · 2019-11-27T14:38:43Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

 	if errs != nil {
 		return utilerrors.NewAggregate(errs)
 	}
 	if warnings := list.Warnings(); warnings != "" {
 		fmt.Fprintf(o.ErrOut, "WARNING: %s\n", warnings)
 	}
+	if o.drainer.DryRun {
+		return nil


Here should the print happen.

yup got it.

sallyom · 2019-12-02T21:26:03Z

/test pull-kubernetes-e2e-gce-device-plugin-gpu

sallyom · 2019-12-03T01:41:42Z

/test pull-kubernetes-integration

sallyom · 2019-12-03T01:41:53Z

/test pull-kubernetes-e2e-gce-100-performance

soltysh

Two small nits and this is ready to go, thanks for keeping up with me 🙃

soltysh · 2019-12-05T20:44:51Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

-		}
-		if err == nil || o.drainer.DryRun {
+		err = o.deleteOrEvictPodsSimple(info)
+		if err == nil {


By now you should be aware that people call me short-if 👮‍♂️ 😉 the above 3 lines can be easily squashed into a single:

if err := o.deleteOrEvictPodsSimple(info); err == nil {

of course : ) thanks - squashed

soltysh · 2019-12-05T20:46:25Z

staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go

@@ -327,6 +325,14 @@ func (o *DrainCmdOptions) deleteOrEvictPodsSimple(nodeInfo *resource.Info) error
 	if warnings := list.Warnings(); warnings != "" {
 		fmt.Fprintf(o.ErrOut, "WARNING: %s\n", warnings)
 	}
+	if o.drainer.DryRun {
+		if len(list.Pods()) > 0 {


No need for this check, for-range will handle that for you

oh right, ok. dropped

…would be deleted.

soltysh

/lgtm
/approve

k8s-ci-robot · 2019-12-05T21:24:04Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: sallyom, soltysh

The full list of commands accepted by this bot can be found here.

The pull request process is described here

Needs approval from an approver in each of these files:

~~staging/src/k8s.io/kubectl/OWNERS~~ [soltysh]

Approvers can indicate their approval by writing /approve in a comment
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soltysh · 2019-12-05T21:24:21Z

/retest

k8s-ci-robot · 2019-12-06T01:38:12Z

@sallyom: The following test failed, say /retest to rerun them all:

Test name	Commit	Details	Rerun command
pull-kubernetes-e2e-gce	`909300b`	link	`/test pull-kubernetes-e2e-gce`

Full PR test history. Your PR dashboard. Please help us cut down on flakes by linking to an open issue when you hit one in your PR.

Instructions for interacting with me using PR comments are available here. If you have questions or suggestions related to my behavior, please file an issue against the kubernetes/test-infra repository. I understand the commands that are listed here.

When running `kubectl drain` in dry-run, list warnings and pods that would be deleted. Kubernetes-commit: 646afd5

k8s-ci-robot added the needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. label Sep 12, 2019

k8s-ci-robot assigned soltysh Sep 12, 2019

k8s-ci-robot added area/kubectl sig/cli Categorizes an issue or PR as relevant to SIG CLI. and removed needs-sig Indicates an issue or PR lacks a `sig/foo` label and requires one. labels Sep 12, 2019

k8s-ci-robot requested review from deads2k and eparis September 12, 2019 19:10

sallyom mentioned this pull request Sep 12, 2019

REQUEST: New membership for sallyom kubernetes/org#1186

Closed

6 tasks

k8s-ci-robot added ok-to-test Indicates a non-member PR verified by an org member that is safe to test. and removed needs-ok-to-test Indicates a PR that requires an org member to verify it is safe to test. labels Sep 13, 2019

sallyom force-pushed the list-pods-dry-run-drain branch 2 times, most recently from 8935c18 to 2de8782 Compare September 13, 2019 15:43

sallyom force-pushed the list-pods-dry-run-drain branch from 2de8782 to 0d06f3a Compare September 23, 2019 20:08

soltysh requested changes Oct 14, 2019

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staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go Outdated Show resolved Hide resolved

k8s-ci-robot added priority/important-longterm Important over the long term, but may not be staffed and/or may need multiple releases to complete. and removed needs-priority Indicates a PR lacks a `priority/foo` label and requires one. labels Oct 14, 2019

sallyom force-pushed the list-pods-dry-run-drain branch from 0d06f3a to 141917d Compare October 14, 2019 21:20

sallyom force-pushed the list-pods-dry-run-drain branch from 141917d to 99aa82b Compare October 14, 2019 21:25

soltysh requested changes Oct 22, 2019

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staging/src/k8s.io/kubectl/pkg/cmd/drain/drain.go Outdated Show resolved Hide resolved

sallyom force-pushed the list-pods-dry-run-drain branch 3 times, most recently from e3207af to 84154d0 Compare October 22, 2019 23:58

soltysh requested changes Nov 27, 2019

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sallyom force-pushed the list-pods-dry-run-drain branch from 84154d0 to 993d4a1 Compare December 2, 2019 20:53

sallyom force-pushed the list-pods-dry-run-drain branch from 993d4a1 to c98a0d9 Compare December 5, 2019 17:13

soltysh requested changes Dec 5, 2019

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When running kubectl drain in dry-run, list warnings and pods that …

909300b

…would be deleted.

sallyom force-pushed the list-pods-dry-run-drain branch from c98a0d9 to 909300b Compare December 5, 2019 21:16

soltysh approved these changes Dec 5, 2019

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k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Dec 5, 2019

k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Dec 5, 2019

k8s-ci-robot merged commit 646afd5 into kubernetes:master Dec 6, 2019

k8s-ci-robot added this to the v1.18 milestone Dec 6, 2019

wking pushed a commit to wking/kubernetes that referenced this pull request Jul 21, 2020

Merge pull request kubernetes#82660 from sallyom/list-pods-dry-run-drain

24f2b8d

When running `kubectl drain` in dry-run, list warnings and pods that would be deleted. Kubernetes-commit: 646afd5

When running kubectl drain in dry-run, list warnings and pods that would be deleted. #82660

When running kubectl drain in dry-run, list warnings and pods that would be deleted. #82660

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k8s-ci-robot commented Dec 6, 2019

When running `kubectl drain` in dry-run, list warnings and pods that would be deleted. #82660

When running `kubectl drain` in dry-run, list warnings and pods that would be deleted. #82660

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