»Ingress Gateways

Ingress gateways enable ingress traffic from services outside the Consul service mesh to services inside the Consul service mesh. An ingress gateway is a type of proxy and must be registered as a service in Consul, with the kind set to "ingress-gateway". They are an entrypoint for outside traffic and allow you to define what services should be exposed and on what port. You configure an ingress gateway by defining a set of listeners that each map to a set of backing services.

To enable easier service discovery, a new Consul DNS subdomain is provided, on <service>.ingress.<domain>.

For listeners with a protocol other than tcp, multiple services can be specified for a single listener. In this case, the ingress gateway relies on host/authority headers to decide the service that should receive the traffic. The host used to match traffic defaults to the Consul DNS ingress subdomain, but can be changed using the hosts field.

Ingress Gateway Architecture

»Prerequisites

Ingress gateways also require that your Consul datacenters are configured correctly:

  • You'll need to use Consul version 1.8.0 or newer.
  • Consul Connect must be enabled on the datacenter's Consul servers.
  • gRPC must be enabled on all client agents.

Currently, Envoy is the only proxy with ingress gateway capabilities in Consul.

»Running and Using an Ingress Gateway

For a complete example of how to allow external traffic inside your Consul service mesh, review the ingress gateway tutorial.

»Ingress Gateway Configuration

Ingress gateways are configured in service definitions and registered with Consul like other services, with two exceptions. The first is that the kind must be "ingress-gateway". Second, the ingress gateway service definition may contain a Proxy.Config entry just like a Connect proxy service, to define opaque configuration parameters useful for the actual proxy software. For Envoy there are some supported gateway options as well as escape-hatch overrides.