Implement curl KeepAlive for watch connections

[hirishh]

Hello,

I've implemented a simple way to enable keepalive as suggested in #202 (comment)

I'm activating it only if "watch=1" is passed as queryParameters and keepalive is enabled in the clientApi configuration.
If you want this to be different, please advice, and I will change the implementation.

I've tested it with watch_list_pod example and using wireshark:

Best,

hirishh

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[brendandburns]

Unfortunately, all of this code is generated, which means that the next time we regenerate, this change will be overridden.

The right place to fix this is in the generator itself:

https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/C-libcurl/apiClient.h.mustache
https://github.com/OpenAPITools/openapi-generator/blob/master/modules/openapi-generator/src/main/resources/C-libcurl/apiClient.c.mustache

They've generally been really good about merging PRs relatively quickly.

Once the generator is updated, we can regenerate the code to pick up the change.

Sorry for the complexity, but generated code is the only way we can keep up with the very large surface area of the Kubernetes API.

[brendandburns]

I also suspect that they won't accept the isWatchCall part since it is very kubernetes specific. I think the right thing to do is probably to implement a watch function or some-such that creates a separate API client and sets the config to do keepAlive. I'll leave it to you to figure out the approach that you like best.

[hirishh]

Thank you for the information. I will try to do a PR there.

Honestly, I believe there is no need to do a check like "isWatchCall". Activating the keepalive has no consequences for normal calls.

[brendandburns]

If the upstream code generator is ok to merge it without the check, we'll pick it up from there.

Thanks! (and apologies again for the complication)

[hirishh]

FYI: OpenAPITools/openapi-generator#21613

[brendandburns]

Looks like the PR in the generator merged, I will see about regenerating.

[hirishh]

Looks like the PR in the generator merged, I will see about regenerating.

If you give me some more days, I'm going to do a PR tomorrow about "pre-invoke-callback" proposal (OpenAPITools/openapi-generator#21613 (comment)), so we can have a version where programmers can freely configure the curl handler

[hirishh]

Here we go: OpenAPITools/openapi-generator#21654

[brendandburns]

Ok sounds good, I will hold off on generating. Thanks for doing this!

[hirishh]

Ok sounds good, I will hold off on generating. Thanks for doing this!

You can proceed now :)

[k8s-ci-robot]

PR needs rebase.

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[brendandburns]

Closing because #280 merged. Thanks for the patience and working in the code generator.