cmd/contour: allow Kube client QPS/burst configuration

[skriss]

Allows the Kubernetes client's QPS and burst
to be configured for the contour serve command.

Signed-off-by: Steve Kriss krisss@vmware.com

Still doing some testing with this but might be nice to include in 1.24 to see if it helps with scale issues.

[skriss]

Interesting, found https://pkg.go.dev/sigs.k8s.io/controller-runtime/pkg/client/config#GetConfig -- looks like controller-runtime defaults these to 20/30 instead of the 5/10 that client-go uses (but we're not currently using the controller-runtime code path, so we're getting 5/10 as the defaults).

[codecov]

Codecov Report

Merging #5003 (6b128e8) into main (6fb5a23) will decrease coverage by 0.15%.
The diff coverage is 5.40%.

Additional details and impacted files

@@            Coverage Diff             @@
##             main    #5003      +/-   ##
==========================================
- Coverage   77.60%   77.46%   -0.15%     
==========================================
  Files         138      138              
  Lines       16837    16869      +32     
==========================================
  Hits        13067    13067              
- Misses       3516     3548      +32     
  Partials      254      254              

Impacted Files	Coverage Δ
internal/k8s/clients.go	0.00% <0.00%> (ø)
pkg/config/parameters.go	86.97% <ø> (ø)
cmd/contour/serve.go	22.22% <15.38%> (-0.07%)	⬇️
internal/sorter/sorter.go	97.95% <0.00%> (-1.03%)	⬇️

[skriss]

Quick ad-hoc test confirms that these flags are working and make a difference. I created 10 HTTPProxies at once and observed the timestamps of their updates (note there are 20 updates total because each one gets status.ingress and status.conditions set separately):

1. With default QPS/burst settings, takes nearly 2 seconds to get through all updates:

time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.613463" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.616942" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.620470" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.623878" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.626612" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.632019" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.635534" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.639589" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.642808" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.646583" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.649964" context=StatusUpdateHandler
time="2023-01-25T19:55:26Z" level=info msg="Updating resource at Jan 25 19:55:26.818779" context=StatusUpdateHandler
time="2023-01-25T19:55:27Z" level=info msg="Updating resource at Jan 25 19:55:27.024993" context=StatusUpdateHandler
time="2023-01-25T19:55:27Z" level=info msg="Updating resource at Jan 25 19:55:27.222049" context=StatusUpdateHandler
time="2023-01-25T19:55:27Z" level=info msg="Updating resource at Jan 25 19:55:27.418763" context=StatusUpdateHandler
time="2023-01-25T19:55:27Z" level=info msg="Updating resource at Jan 25 19:55:27.623177" context=StatusUpdateHandler
time="2023-01-25T19:55:27Z" level=info msg="Updating resource at Jan 25 19:55:27.822516" context=StatusUpdateHandler
time="2023-01-25T19:55:28Z" level=info msg="Updating resource at Jan 25 19:55:28.024864" context=StatusUpdateHandler
time="2023-01-25T19:55:28Z" level=info msg="Updating resource at Jan 25 19:55:28.221517" context=StatusUpdateHandler
time="2023-01-25T19:55:28Z" level=info msg="Updating resource at Jan 25 19:55:28.420659" context=StatusUpdateHandler

2. With QPS=20, burst=30, takes under half a second:

time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.704255" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.709776" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.712717" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.715430" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.718053" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.722608" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.726199" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.730188" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.735980" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.740747" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.744238" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.845356" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.849038" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.851939" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.855219" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.857822" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.860963" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.863600" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.866590" context=StatusUpdateHandler
time="2023-01-25T19:56:45Z" level=info msg="Updating resource at Jan 25 19:56:45.869894" context=StatusUpdateHandler

[skriss]

This would only be relevant for #5001 if there are lots of updates queued at once, but still likely a helpful knob to have for some clusters.

[sunjayBhatia]

Given we kinda need to configure this via flag/ConfigMap to suit different use cases I'm on the fence now about eventually moving to the ContourConfiguration CRD, seems like a hassle to add more CLI flags which we have to do since this one in particular doesn't really work to put as a field on a resource we have to fetch from the API server, WDYT?

[sunjayBhatia]

(implementation looks good, like the logging bit that lets us know what it is configured to, nice to see)

[skriss]

Given we kinda need to configure this via flag/ConfigMap to suit different use cases I'm on the fence now about eventually moving to the ContourConfiguration CRD, seems like a hassle to add more CLI flags which we have to do since this one in particular doesn't really work to put as a field on a resource we have to fetch from the API server, WDYT?

Yeah, I was having similar thoughts as I went through this and realized where it needed to go. Definitely something for us to revisit and see if it still makes sense.

[skriss]

@sunjayBhatia are you OK with merging this now for inclusion in 1.24? Just wanted to check since we've already cut the RC.

[sunjayBhatia]

@sunjayBhatia are you OK with merging this now for inclusion in 1.24? Just wanted to check since we've already cut the RC.

sounds good to me, the default behavior should be the same so lower risk