Support for istio's warmupDurationSecs

[recarga-brubs]

Describe the feature

Istio added in 2022 the ability to "warm up" traffic slowly with a new load balancer property called warmupDurationSecs https://istio.io/latest/docs/reference/config/networking/destination-rule/#LoadBalancerSettings

Flagger should also support LEAST_REQUEST loadbalancer configuration https://istio.io/latest/docs/reference/config/networking/destination-rule/#LoadBalancerSettings-SimpleLB

Proposed solution

Add support for new istio loadbalancer features so a configuration like this would be possible

...
    trafficPolicy:
      loadBalancer:
        simple: LEAST_REQUEST
        warmupDurationSecs: 30s
...

Any alternatives you've considered?

No

[aryan9600]

@recarga-brubs thanks for opening this issue. would you like to take it on?

[flaviomrjr]

@aryan9600 is there any chance to add this feature?
It would be really helpful to enable this feature as shown in this thread:
https://stackoverflow.com/questions/74517652/gradually-warm-java-application-in-k8s-with-istio

[S-mishina]

@aryan9600
Nice to meet you.
I addressed this issue here.
If I am wrong, please point it out to me.