add timeout config in yurthub to handle those watch requests without …

[AndyEWang]

What type of PR is this?

/kind enhancement

What this PR does / why we need it:

When yurthub takes charge of apiserver and if there is no timeoutSeconds parameter in watch requests, yurthub returns immediately. This causes the requester to retry watch request frantically. Also both yurthub and requester begin rolling logs.
So to add a new startup option for yurthub to define the default watch timeout and also give a default value(1800s like apiserver) to this option.

Does this PR introduce a user-facing change?

A new optional arg "--min-request-timeout" is added in yurthub startup command. If not set, the default value is 1800s.

[openyurt-bot]

Welcome @AndyEWang! It looks like this is your first PR to openyurtio/openyurt 🎉

[Congrool]

I also notice this problem, and my case is calico that results in watch request flood. It's reasonable to add timeout for watch request when offline.

BTW, is there any reason for the value 1800s?

[AndyEWang]

is there any reason for the value 1800s?

just refer to https://kubernetes.io/docs/reference/command-line-tools-reference/kube-apiserver/ --min-request-timeout int Default: 1800

[codecov]

Codecov Report

Merging #1056 (e5a8cd6) into master (5457b55) will increase coverage by 0.02%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1056      +/-   ##
==========================================
+ Coverage   49.45%   49.47%   +0.02%     
==========================================
  Files          96       96              
  Lines       13054    13056       +2     
==========================================
+ Hits         6456     6460       +4     
+ Misses       6061     6060       -1     
+ Partials      537      536       -1     

Flag	Coverage Δ
unittests	49.47% <100.00%> (+0.02%)	⬆️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
pkg/yurthub/proxy/local/local.go	70.13% <100.00%> (+0.42%)	⬆️
pkg/util/iptables/iptables.go	87.67% <0.00%> (+0.54%)	⬆️

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[Congrool]

Another question here, what's the behaviour of APIServer when handling the watch request with timeoutSeconds parameter?

For example, if we set --min-request-timeout=1800 for APIServer, and the coming watch request is /api/v1/nodes?watch=true&timeoutSeconds=32, how much time before APIServer timing it out?

[AndyEWang]

apiserver respects the timeoutSeconds parameter and only use --min-request-timeout when timeoutSeconds is zero or not passed.

[Congrool]

/lgtm

[rambohe-ch]

/approve

[openyurt-bot]

[APPROVALNOTIFIER] This PR is APPROVED

This pull-request has been approved by: AndyEWang, rambohe-ch

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• OWNERS [rambohe-ch]

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