Add write-config-to to scheduler #62515

resouer · 2018-04-13T05:22:10Z

What this PR does / why we need it:
Scheduler should be able to write its default configure to file. This actually applies to all components which claims options other than --config will be deprecated.

Otherwise, users will be super confused to find out how to write a proper config file to these components.

See: https://stackoverflow.com/questions/47966440/how-to-create-a-config-file-for-kube-scheduler-to-use-by-the-config-argument
ref: #52562

Which issue(s) this PR fixes (optional, in fixes #<issue number>(, fixes #<issue_number>, ...) format, will close the issue(s) when PR gets merged):
Fixes #58805

Usage:

./_output/bin/kube-scheduler --write-config-to /tmp/kube-scheduler.yaml

Special notes for your reviewer:
This should have been fixed several releases ago, so lets include it in 1.11

Release note:

Add write-config-to to scheduler

resouer · 2018-04-13T05:26:34Z

cc @corest , you should be interested in

xiangpengzhao

I like this idea, but maybe we can just document an straightforward example somewhere rather than coding ?

xiangpengzhao · 2018-04-13T06:05:47Z

cmd/kube-scheduler/app/server.go

@@ -167,8 +172,8 @@ func NewOptions() (*Options, error) {
 }

 func (o *Options) Complete() error {
-	if len(o.ConfigFile) == 0 {
-		glog.Warning("WARNING: all flags other than --config are deprecated. Please begin using a config file ASAP.")
+	if len(o.ConfigFile) == 0 && len(o.WriteConfigTo) == 0 {


When len(o.ConfigFile) == 0 but len(o.WriteConfigTo) != 0, we still need to apply these deprecated stuff, but this condition skips this case. So I think we don't need to add len(o.WriteConfigTo) == 0 here.

Nope. It's just a warning.

But o.applyDeprecatedHealthzAddressToConfig() and friends aren't just warning. They apply healthzAddress (which is the flag --address), etc. So if users specify flags like this --write-config-to ./scheduler.yaml --address 1.2.3.4, the flag --address 1.2.3.4 won't take effect. Maybe I miss something here? :)

Mis-read again... When --write-config-to is specified, kube-scheduler will write the config and exit. So it's ok as-is.

xiangpengzhao · 2018-04-13T06:13:26Z

cmd/kube-scheduler/app/server.go

@@ -106,6 +110,7 @@ type Options struct {
 // AddFlags adds flags for a specific SchedulerServer to the specified FlagSet
 func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&o.ConfigFile, "config", o.ConfigFile, "The path to the configuration file.")
+	fs.StringVar(&o.WriteConfigTo, "write-config-to", o.WriteConfigTo, "If set, write the default configuration values to this file and exit.")


IIUC, writeConfigFile writes both default and configured values which are loaded from --config if specified, so the description of this flag is inaccurate.

Actually, this patch always generate default values, which is expected.

Yeah you're right. I mis-read some codes.

resouer · 2018-04-13T06:44:15Z

I like this idea, but maybe we can just document an straightforward example somewhere rather than coding ?

Actually as we are migrating to ComponentConfig , --write-config-to is now a mandatory option and it has already been added to several components like kube-proxy I believe.

k82cn · 2018-04-13T11:06:49Z

cmd/kube-scheduler/app/server.go

@@ -106,6 +110,7 @@ type Options struct {
 // AddFlags adds flags for a specific SchedulerServer to the specified FlagSet
 func (o *Options) AddFlags(fs *pflag.FlagSet) {
 	fs.StringVar(&o.ConfigFile, "config", o.ConfigFile, "The path to the configuration file.")
+	fs.StringVar(&o.WriteConfigTo, "write-config-to", o.WriteConfigTo, "If set, write the default configuration values to this file and exit.")


If the config is not nil, the value is not default, right?

Right now, it only write default values from schema, which is my intention.

k82cn · 2018-04-13T11:07:02Z

/approve

resouer · 2018-04-13T18:45:18Z

@bsalamat @k82cn Currently, I intentionally make it write default values to file only, but please let me know if you think we should write out real values if --config is provided.

But it's wired in my opinion:

kube-scheduler --config=/tmp/scheduler.yaml --write-config-to /tmp/temp

So my 2c is let's keep current design and I can make those two flags exclusive. After all, it does make sense to use them together.

k82cn · 2018-04-16T12:01:33Z

So my 2c is let's keep current design and I can make those two flags exclusive. After all, it does make sense to use them together.

That's ok to me. If writing out real values is NOT complex, it seems better as it cover more case (writting default value if no --config).

resouer · 2018-04-16T21:14:19Z

@k82cn There's no tech blocker. Just hope to make sure this consistent with users expectation.

@AshleyByeUK @tiukhtinvladimir I saw you are tracking this issue, do you expect --write-config-to generate user set values when used with --config, or it's better to stick it to always default. Or you just don't care too much?

kennethredler · 2018-04-16T21:50:14Z

@resouer IMO, do default first. Then iterate to include --config values on next round.

k82cn · 2018-04-16T23:22:54Z

There's no tech blocker. Just hope to make sure this consistent with users expectation.

Both can cover the original case: writing the default value into a file. Working with --config provides more options, but don-t want to put much effort on a "maybe" case.

junglie85 · 2018-04-17T06:33:56Z

@resouer I think it makes sense for --write-config-to to provide default values. If --config flag is applied, it would seem more appropriate to write out the current config - this latter flag is likely to only be an interim requirement to allow existing command line arguments to be converted to a config file, right?

Ultimately, I'm not overly fussed, but this seems like the sanest approach.

resouer · 2018-04-17T17:38:19Z

@AshleyByeUK Correct.

Thanks guys. According to current discussion, I will make -write-config-to write out default values, but if --config is provided at the same time, it will write out given values.

Change to write provided values if config is set

resouer · 2018-04-18T17:55:52Z

@k82cn Take a final look?

k82cn · 2018-04-18T22:59:32Z

/lgtm

k8s-github-robot · 2018-04-18T23:00:09Z

[MILESTONENOTIFIER] Milestone Pull Request Needs Approval

@k82cn @resouer @kubernetes/sig-scheduling-misc

Action required: This pull request must have the status/approved-for-milestone label applied by a SIG maintainer. If the label is not applied within 2 days, the pull request will be moved out of the v1.11 milestone.

Pull Request Labels

sig/scheduling: Pull Request will be escalated to these SIGs if needed.
priority/important-soon: Escalate to the pull request owners and SIG owner; move out of milestone after several unsuccessful escalation attempts.
kind/feature: New functionality.

Help

k8s-ci-robot · 2018-04-18T23:00:23Z

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: k82cn, resouer

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:

~~cmd/kube-scheduler/OWNERS~~ [k82cn]

Approvers can indicate their approval by writing /approve in a comment
Approvers can cancel approval by writing /approve cancel in a comment

k8s-github-robot · 2018-04-19T00:53:17Z

Automatic merge from submit-queue (batch tested with PRs 62481, 62643, 61877, 62515). If you want to cherry-pick this change to another branch, please follow the instructions here.

resouer added this to the v1.11 milestone Apr 13, 2018

k8s-ci-robot added release-note Denotes a PR that will be considered when it comes time to generate release notes. size/M Denotes a PR that changes 30-99 lines, ignoring generated files. cncf-cla: yes Indicates the PR's author has signed the CNCF CLA. labels Apr 13, 2018

k8s-ci-robot requested review from k82cn and ravisantoshgudimetla April 13, 2018 05:22

k8s-ci-robot added the sig/scheduling Categorizes an issue or PR as relevant to SIG Scheduling. label Apr 13, 2018

k8s-github-robot added the milestone/incomplete-labels label Apr 13, 2018

resouer added priority/important-soon Must be staffed and worked on either currently, or very soon, ideally in time for the next release. kind/feature Categorizes issue or PR as related to a new feature. labels Apr 13, 2018

k8s-github-robot added milestone/needs-approval and removed milestone/incomplete-labels labels Apr 13, 2018

xiangpengzhao reviewed Apr 13, 2018

View reviewed changes

resouer mentioned this pull request Apr 13, 2018

Use ComponentConfig for kube-scheduler kubernetes/kubeadm#528

Closed

k82cn reviewed Apr 13, 2018

View reviewed changes

k8s-ci-robot added the approved Indicates a PR has been approved by an approver from all required OWNERS files. label Apr 13, 2018

junglie85 mentioned this pull request Apr 15, 2018

kube-scheduler doesn not have --write-config-to option #58805

Closed

resouer added 2 commits April 17, 2018 11:02

Add write-config-to to scheduler

c88cd33

Change to write provided values if config is set

Update generated bazel

3e918c5

resouer force-pushed the fix-58805 branch from 61c3585 to 3e918c5 Compare April 17, 2018 18:03

k8s-ci-robot assigned k82cn Apr 18, 2018

k8s-ci-robot added the lgtm "Looks good to me", indicates that a PR is ready to be merged. label Apr 18, 2018

k8s-github-robot merged commit 2c54e9c into kubernetes:master Apr 19, 2018

resouer deleted the fix-58805 branch April 19, 2018 18:48

neoaggelos mentioned this pull request Feb 15, 2022

Add --write-config-to option to kubelet #108118

Open

Provide feedback

Saved searches

Use saved searches to filter your results more quickly

Add write-config-to to scheduler #62515

Add write-config-to to scheduler #62515

resouer commented Apr 13, 2018 •

edited

Loading

resouer commented Apr 13, 2018 •

edited

Loading

xiangpengzhao left a comment

xiangpengzhao Apr 13, 2018 •

edited

Loading

resouer Apr 13, 2018

xiangpengzhao Apr 13, 2018

xiangpengzhao Apr 13, 2018

xiangpengzhao Apr 13, 2018

resouer Apr 13, 2018

xiangpengzhao Apr 13, 2018

resouer commented Apr 13, 2018 •

edited

Loading

k82cn Apr 13, 2018

resouer Apr 13, 2018 •

edited

Loading

k82cn commented Apr 13, 2018

resouer commented Apr 13, 2018 •

edited

Loading

k82cn commented Apr 16, 2018

resouer commented Apr 16, 2018 •

edited

Loading

kennethredler commented Apr 16, 2018

k82cn commented Apr 16, 2018

junglie85 commented Apr 17, 2018

resouer commented Apr 17, 2018

resouer commented Apr 18, 2018

k82cn commented Apr 18, 2018

k8s-github-robot commented Apr 18, 2018

k8s-ci-robot commented Apr 18, 2018

k8s-github-robot commented Apr 19, 2018

Add write-config-to to scheduler #62515

Add write-config-to to scheduler #62515

Conversation

resouer commented Apr 13, 2018 • edited Loading

resouer commented Apr 13, 2018 • edited Loading

xiangpengzhao left a comment

Choose a reason for hiding this comment

xiangpengzhao Apr 13, 2018 • edited Loading

Choose a reason for hiding this comment

resouer Apr 13, 2018

Choose a reason for hiding this comment

xiangpengzhao Apr 13, 2018

Choose a reason for hiding this comment

xiangpengzhao Apr 13, 2018

Choose a reason for hiding this comment

xiangpengzhao Apr 13, 2018

Choose a reason for hiding this comment

resouer Apr 13, 2018

Choose a reason for hiding this comment

xiangpengzhao Apr 13, 2018

Choose a reason for hiding this comment

resouer commented Apr 13, 2018 • edited Loading

k82cn Apr 13, 2018

Choose a reason for hiding this comment

resouer Apr 13, 2018 • edited Loading

Choose a reason for hiding this comment

k82cn commented Apr 13, 2018

resouer commented Apr 13, 2018 • edited Loading

k82cn commented Apr 16, 2018

resouer commented Apr 16, 2018 • edited Loading

kennethredler commented Apr 16, 2018

k82cn commented Apr 16, 2018

junglie85 commented Apr 17, 2018

resouer commented Apr 17, 2018

resouer commented Apr 18, 2018

k82cn commented Apr 18, 2018

k8s-github-robot commented Apr 18, 2018

k8s-ci-robot commented Apr 18, 2018

k8s-github-robot commented Apr 19, 2018

resouer commented Apr 13, 2018 •

edited

Loading

resouer commented Apr 13, 2018 •

edited

Loading

xiangpengzhao Apr 13, 2018 •

edited

Loading

resouer commented Apr 13, 2018 •

edited

Loading

resouer Apr 13, 2018 •

edited

Loading

resouer commented Apr 13, 2018 •

edited

Loading

resouer commented Apr 16, 2018 •

edited

Loading