Ingress Gateway

Ingress Gateway

v1.8.4+: On Kubernetes, the IngressGateway custom resource is supported in Consul versions 1.8.4+.
v1.8.0+: On other platforms, this config entry is supported in Consul versions 1.8.0+.

The ingress-gateway config entry kind (IngressGateway on Kubernetes) allows you to configure ingress gateways with listeners that expose a set of services outside the Consul service mesh.

For Kubernetes, see Kubernetes Ingress Gateway for more information. For other platforms, see Ingress Gateway.

Note: Configuration entries are global in scope. A configuration entry for a gateway name applies across all federated Consul datacenters. If ingress gateways in different Consul datacenters need to route to different sets of services within their datacenter then the ingress gateways must be registered with different names.
See Ingress Gateway for more information.

Wildcard service specification

Ingress gateways can optionally target all services within a Consul namespace by specifying a wildcard * as the service name. A wildcard specifier allows for a single listener to route traffic to all available services on the Consul service mesh, differentiating between the services by their host/authority header.

A wildcard specifier provides the following properties for an ingress gateway:

All services with the same protocol as the listener will be routable.
The ingress gateway will route traffic based on the host/authority header, expecting a value matching <service-name>.ingress.*, or if using namespaces, <service-name>.ingress.<namespace>.*. This matches the Consul DNS ingress subdomain.

A wildcard specifier cannot be set on a listener of protocol tcp.

Sample Config Entries

TCP listener

Set up a TCP listener on an ingress gateway named “us-east-ingress” to proxy traffic to the “db” service:

Kind = "ingress-gateway"
Name = "us-east-ingress"
Listeners = [
  {
    Port     = 3456
    Protocol = "tcp"
    Services = [
      {
        Name = "db"
      }
    ]
  }
]

Wildcard HTTP listener

Set up a wildcard HTTP listener on an ingress gateway named “us-east-ingress” to proxy traffic to all services in the datacenter. Also make two services available over a custom port with user-provided hosts, and enable TLS on every listener:

Kind = "ingress-gateway"
Name = "us-east-ingress"
TLS {
  Enabled = true
}
Listeners = [
  {
    Port     = 8080
    Protocol = "http"
    Services = [
      {
        Name = "*"
      }
    ]
  },
  {
    Port     = 4567
    Protocol = "http"
    Services = [
      {
        Name  = "api"
        Hosts = ["foo.example.com", "foo.example.com:4567"]
      },
      {
        Name  = "web"
        Hosts = ["website.example.com", "website.example.com:4567"]
      }
    ]
  }
]

HTTP listener with path-based routing

Set up a HTTP listener on an ingress gateway named “us-east-ingress” to proxy traffic to a virtual service named “api”.

Kind = "ingress-gateway"
Name = "us-east-ingress"
Listeners = [
  {
    Port     = 80
    Protocol = "http"
    Services = [
      {
        Name = "api"
      }
    ]
  }
]

The api service is not an actual registered service. It exist as a “virtual” service for L7 configuration only. A service-router (ServiceRouter on Kubernetes) is defined for this virtual service which uses path-based routing to route requests to different backend services:

Kind = "service-router"
Name = "api"
Routes = [
  {
    Match {
      HTTP {
        PathPrefix = "/billing"
      }
    }
    Destination {
      Service = "billing-api"
    }
  },
  {
    Match {
      HTTP {
        PathPrefix = "/payments"
      }
    }
    Destination {
      Service = "payments-api"
    }
  }
]

Available Fields

Kind - Must be set to ingress-gateway
Name (string: <required>) - Set to the name of the gateway being configured.
Namespace (string: "default")

Enterprise

- Specifies the namespace the config entry will apply to. This must be the namespace the gateway is registered in. If omitted, the namespace will be inherited from the request or will default to the default namespace.
Meta (map<string|string>: nil) - Specifies arbitrary KV metadata pairs. Added in Consul 1.8.4.
TLS (TLSConfig: <optional>) - TLS configuration for this gateway.
- Enabled (bool: false) - Set this configuration to enable TLS for every listener on the gateway.
  
  If TLS is enabled, then each host defined in the Host field will be added as a DNSSAN to the gateway’s x509 certificate.
Listeners (array<IngressListener>: <optional>)) - A list of listeners that the ingress gateway should setup, uniquely identified by their port number.
- Port (int: 0) - The port that the listener should receive traffic on.
- Protocol (string: "tcp") - The protocol associated with the listener. One of tcp, http, http2, or grpc.
- Services (array<IngressService>: <optional>) - A list of services to be exposed via this listener. For “tcp” listeners, only a single service is allowed.
  - Name (string: "") - The name of the service that should be exposed through this listener. This can be either a service registered in the catalog, or a service defined only by other config entries. If the wildcard specifier, *, is provided, then ALL services will be exposed through the listener. This is not supported for listener’s with protocol “tcp”.
  - Namespace (string: "")
    
    Enterprise
    
    - The namespace to resolve the service from instead of the current namespace. If empty the current namespace is assumed.
  - Hosts (array<string>: <optional>) - A list of hosts that specify what requests will match this service. This cannot be used with a tcp listener, and cannot be specified alongside a * service name. If not specified, the default domain .ingress.* will be used to match services. Requests must send the correct host to be routed to the defined service.
    
    The wildcard specifier, *, can be used by itself to match all traffic coming to the ingress gateway, if TLS is not enabled. This allows a user to route all traffic to a single service without specifying a host, allowing simpler tests and demos. Otherwise, the wildcard specifier can be used as part of the host to match multiple hosts, but only in the leftmost DNS label. This ensures that all defined hosts are valid DNS records. For example, *.example.com is valid, while example.* and *-suffix.example.com are not.
    
    Note: If a well-known port is not used, i.e. a port other than 80 (http) or 443 (https), then the port must be appended to the host to correctly match traffic. This is defined in the HTTP/1.1 RFC. If TLS is enabled, then the host without the port must be added to the Hosts field as well. TLS verification only matches against the hostname of the incoming connection, and thus does not take into account the port.

ACLs

Configuration entries may be protected by ACLs.

Reading an ingress-gateway config entry requires service:read on the Name field of the config entry.

Creating, updating, or deleting an ingress-gateway config entry requires operator:write.