Architecture

Open API

API - OpenAPI - Swagger

https://swagger.io/docs/specification/about/

AWS API Gateway

The AWS API Gateway is a managed service that provides for a L7 reverse proxy, SSL termination, Authentication - it works with a WAF.

Azure 

The Azure Application Gateway https://docs.microsoft.com/en-us/azure/architecture/microservices/design/gateway is a managed load balancer that provides for a L7 reverse proxy, SSL termination and WAF functionality.

Azure API Management works with the Azure AG to publish API specifications

Kubernetes Ingress Controller

Envoy Kubernetes API Gateway

https://www.envoyproxy.io/docs/envoy/latest/start/distro/ambassador

https://www.consul.io/docs/platform/k8s/run.html

Consul Service Mesh

https://www.consul.io/intro/index.html

Commercial

3Scale - Redhat

https://www.3scale.net/

Links

https://www.nginx.com/blog/building-microservices-using-an-api-gateway/