elasticloadbalancingv2: support target group health attributes

[mazyu36]

Describe the feature

In L2 Construct, the following target group attributes are not supported yet.

• target_group_health.dns_failover.minimum_healthy_targets.count - The minimum number of targets that must be healthy. If the number of healthy targets is below this value, mark the zone as unhealthy in DNS, so that traffic is routed only to healthy zones. The possible values are off or an integer from 1 to the maximum number of targets. The default is off.
  • target_group_health.dns_failover.minimum_healthy_targets.percentage - The minimum percentage of targets that must be healthy. If the percentage of healthy targets is below this value, mark the zone as unhealthy in DNS, so that traffic is routed only to healthy zones. The possible values are off or an integer from 1 to 100. The default is off.
  • target_group_health.unhealthy_state_routing.minimum_healthy_targets.count - The minimum number of targets that must be healthy. If the number of healthy targets is below this value, send traffic to all targets, including unhealthy targets. The possible values are 1 to the maximum number of targets. The default is 1.
  • target_group_health.unhealthy_state_routing.minimum_healthy_targets.percentage - The minimum percentage of targets that must be healthy. If the percentage of healthy targets is below this value, send traffic to all targets, including unhealthy targets. The possible values are off or an integer from 1 to 100. The default is off.

https://docs.aws.amazon.com/ja_jp/AWSCloudFormation/latest/UserGuide/aws-properties-elasticloadbalancingv2-targetgroup-targetgroupattribute.html

Use Case

To set target group attributes about target group health.

Proposed Solution

Add properties to baseTargetGroup Construct for attributes.

Other Information

No response

Acknowledgements

• [X] I may be able to implement this feature request
• [ ] This feature might incur a breaking change

CDK version used

all

Environment details (OS name and version, etc.)

all

[ashishdhingra]

This feature request:

• Should not be confused with AWS::ElasticLoadBalancingV2::LoadBalancer LoadBalancerAttribute , for which load_balancing.cross_zone.enabled is set in base-load-balancer.ts.
• It requests adding support for mentioned attribute for AWS::ElasticLoadBalancingV2::TargetGroup TargetGroupAttribute.

@mazyu36 Thanks for creating feature request. Feel free to contribute PR.