feat(elasticloadbalancingv2): Add support for application cookies

[robertd]

https://aws.amazon.com/about-aws/whats-new/2021/02/application-load-balancer-supports-application-cookie-stickiness/

Maybe I shouldn't have deprecated stickinessCookieDuration ... which is essentially a rename to loadBalancerStickinessCookieDuration.... but that can be easily reverted based on the feedback I recieve.

As always... feedback is much appreciated. Thanks! 👍

edit:

lb_cookie

app_cookie

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[gitpod-io]

[robertd]

The more I think about this... the more I want to simply reuse stickinessCookieDuration and update all the docs. Pretty much if you provide stickinessCookieDuration param then it's lb_cookie, and if you provide both stickinessCookieDuration & appCookieName params then it becomes app_cookie. Not sure if that would confuse the users though :).

[robertd]

The more I think about this... the more I want to simply reuse stickinessCookieDuration and update all the docs. Pretty much if you provide stickinessCookieDuration param then it's lb_cookie, and if you provide both stickinessCookieDuration & appCookieName params then it becomes app_cookie. Not sure if that would confuse the users though :).

@njlynch When time permits let me know what your initial thoughts are and I'll definitely modify this PR based on your guidance/feedback. Thanks!

[njlynch]

I agree -- I think we can keep the stickinessCookieDuration as working for both, and the user can set the appCookieName if they want to base stickiness based on the application cookie. Given you can't set both (LB- and app-based stickiness), I think overloading the cookie duration won't be needlessly confusing.

[robertd]

Thanks @njlynch... I'm on it.

[robertd]

@njlynch fixed... please review.

[njlynch]

Looks great. Lots of minor nit-picks.

Pull request has been modified.