Consuming cloud-provider appears problematic in 1.20

[NeilW]

I've just upgraded the Brightbox cloud-controller to 1.20 and, in common with the AWS updates, I found the new interfaces into the library to be problematic, and the sample 'main' code to not work as I'd expected.

Primarily the call to s.Config appears to be too early and the command line flags have not been enumerated at that point, so version and help doesn't work and neither do command line flags.

I had to rewrite the top level interface along the lines of the AWS controller and move the call to s.Config back within the Cobra command function.

Of course it's possible I've completely misunderstood how this interface is supposed to work in its new configuration and if anybody can explain that I'd be grateful.

The code I ended up with is here: https://github.com/brightbox/brightbox-cloud-controller-manager/blob/8acb44fc63a74ca14c96daec039a4d2473881e52/app/cloudcontroller.go

Which is based on the AWS main file here: https://github.com/kubernetes/cloud-provider-aws/blob/3b384bb6e144446cb8015ab83269d6f99ac00898/cmd/aws-cloud-controller-manager/main.go

[andrewsykim]

@NeilW thanks for feedback, not rendering the command line flags prior to s.Config sounds like a bug to me. @cici37 is this something you can take a look at?

Which flags specifically were not being rendered? Seems like maybe those should be added here:

https://github.com/kubernetes/kubernetes/blob/9465d95ea69bb5ee140df605f0b7960d5ca0b758/staging/src/k8s.io/cloud-provider/options/options.go#L127-L147

[NeilW]

All of them since the call to Config triggers a Validate which fails with '--cloud-provider cannot be empty'.

The flags aren't setup until

cloud-provider/app/controllermanager.go

Line 106 in 22476e0

for _, f := range namedFlagSets.FlagSets {

[cici37]

Thank you for raising it. I will work on it.
/assign

[andrewsykim]

@cici37 any updates on this?