Consul
Ingress Gateway Configuration Entry
This topic provides reference information for the ingress-gateway
configuration entry.
Introduction
You can define an ingress-gateway
configuration entry to connect the Consul service mesh to a set of external services. The specification for ingress gateways include a listeners
configuration, which exposes the service mesh to the external services. Use camel case (IngressGateway
) to declare an ingress gateway configuration entry on Kubernetes.
Refer to the Kubernetes Ingress Gateway documentation for information about configuring ingress gateways on Kubernetes.
For other platforms, see Ingress Gateway.
Requirements
- Consul versions 1.8.4+ is required to use the
IngressGateway
custom resource on Kubernetes. - Consul versions 1.8.0+ is required to use the
ingress-gateway
custom resource on all other platforms.
Usage
- Verify that your datacenter meets the conditions specified in the Requirements.
- Create a file containing the configuration entry settings (see Configuration).
- Apply the configuration settings using one of the following methods:
- Kubernetes CRD: Refer to the Custom Resource Definitions documentation for details.
- Issue the
consul config write
command: Refer to the Consul Config Write documentation for details.
Configuration
Use the following syntax to configure an ingress gateway.
Kind = "ingress-gateway"
Name = "<name for the gateway>"
Listeners = [
{
Port = <external service port>
Protocol = "<protocol used by external service>"
Services = [
{
Name = "<name of external service>"
}
]
}
]
Refer to the Available Fields section for complete information about all ingress gateway configuration entry options and to the Example Configurations section for example use-cases.
Scope
Configuration entries are global in scope. A configuration entry for a gateway name applies across the default partition of 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 or partitions. 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
.
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
.
Example Configurations
The following examples describe possible use-cases for ingress gateway configuration entries.
TCP listener
The following example sets up a TCP listener on an ingress gateway named us-east-ingress
to proxy traffic to the db
service. The Consul Enterprise version also posits the gateway listener inside the default
namespace and the team-frontend
admin partition:
Kind = "ingress-gateway"
Name = "us-east-ingress"
Listeners = [
{
Port = 3456
Protocol = "tcp"
Services = [
{
Name = "db"
}
]
}
]
Wildcard HTTP Listener
In the following example, two listeners are configured on an ingress gateway named us-east-ingress
:
- The first listener is configured to listen on port
8080
and uses a wildcard (*
) to proxy traffic to all services in the datacenter. - The second listener exposes the
api
andweb
services on port4567
at user-provided hosts. - TLS is enabled on every listener.
- The
max_connections
of the ingress gateway proxy to each upstream cluster is set to 4096.
The Consul Enterprise version implements the following additional configurations:
- The ingress gateway is set up in the
default
namespace and proxies traffic to all services in thefrontend
namespace. - The
api
andweb
services are proxied to team-specific admin partitions:
Kind = "ingress-gateway"
Name = "us-east-ingress"
TLS {
Enabled = true
}
Defaults {
MaxConnections = 4096
}
Listeners = [
{
Port = 8080
Protocol = "http"
Services = [
{
Name = "*"
}
]
},
{
Port = 4567
Protocol = "http"
Services = [
{
Name = "api"
Hosts = ["foo.example.com"]
},
{
Name = "web"
Hosts = ["website.example.com"]
}
]
}
]
HTTP listener with Path-based Routing
The following example sets up an HTTP listener on an ingress gateway named us-east-ingress
to proxy
traffic to a virtual service named api
. In the Consul Enterprise version, us-east-ingress
is set up in the default
namespace and default
partition.
In this use-case, internal-only debug headers should be stripped before responding to external clients. Requests to internal services should also be labelled to indicate which gateway they came through.
Kind = "ingress-gateway"
Name = "us-east-ingress"
Listeners = [
{
Port = 80
Protocol = "http"
Services = [
{
Name = "api"
RequestHeaders {
Add {
"x-gateway" = "us-east-ingress"
}
}
ResponseHeaders {
Remove = ["x-debug"]
}
}
]
}
]
For this use-case, the api
service is not an actual registered service. It exists as a virtual service for L7 configuration only. A service-router
(ServiceRouter
on Kubernetes) is defined for the virtual service that 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
You can specify the following parameters to configure ingress gateway configuration entries.
Kind
- Must be set toingress-gateway
Name
(string: <required>)
- Set to the name of the gateway being configured.Namespace
(string: `default`)
Enterprise - Specifies the namespace in which the configuration entry will apply. The value must match the namespace in which the gateway is registered. If omitted, the namespace will be inherited from thens
request parameter (refer to theconfig
API endpoint documentation). or will default to thedefault
namespace.Meta
(map<string|string>: nil)
- Specifies arbitrary KV metadata pairs. Added in Consul 1.8.4.Partition
(string: "default")
Enterprise - Specifies the admin partition in which the configuration will apply. The value must match the partition in which the gateway is registered. If omitted, the partition will be inherited from the request (refer to theconfig
API endpoint documentation). See Admin Partitions for additional information.TLS
(TLSConfig: <optional>)
- TLS configuration for this gateway.Enabled
(bool: false)
- Set this configuration totrue
to enable built-in TLS for every listener on the gateway.
If TLS is enabled, then each host defined in each service'sHosts
fields will be added as a DNSSAN to the gateway's x509 certificate.TLSMinVersion
(string: "")
- Set the default minimum TLS version supported for the gateway's listeners. One ofTLS_AUTO
,TLSv1_0
,TLSv1_1
,TLSv1_2
, orTLSv1_3
. If unspecified, Envoy v1.22.0 and newer will default to TLS 1.2 as a min version, while older releases of Envoy default to TLS 1.0.TLSMaxVersion
(string: "")
- Set the default maximum TLS version supported for the gateway's listeners. Must be greater than or equal toTLSMinVersion
. One ofTLS_AUTO
,TLSv1_0
,TLSv1_1
,TLSv1_2
, orTLSv1_3
.CipherSuites
(array<string>: <optional>)
- Set the default list of TLS cipher suites for the gateway's listeners to support when negotiating connections using TLS 1.2 or earlier. If unspecified, Envoy will use a default server cipher list. The list of supported cipher suites can seen inconsul/types/tls.go
and is dependent on underlying support in Envoy. Future releases of Envoy may remove currently-supported but insecure cipher suites, and future releases of Consul may add new supported cipher suites if any are added to Envoy.SDS
(SDSConfig: <optional>)
- Defines a set of parameters that configures the gateway to load TLS certificates from an external SDS service. See SDS for more details on usage.
SDS properties defined in this field are used as defaults for all listeners on the gateway.ClusterName
(string)
- Specifies the name of the SDS cluster from which Consul should retrieve certificates. This cluster must be specified in the Gateway's bootstrap configuration.CertResource
(string)
- Specifies an SDS resource name. Consul will request the SDS resource name when fetching the certificate from the SDS service. Setting this causes all listeners to be served exclusively over TLS with this certificate unless overridden by listener-specific TLS configuration.
Defaults
(IngressServiceConfig: <optional>)
- Default configuration that applies to all upstreams.MaxConnections
(int: 0)
- The maximum number of connections a service instance will be allowed to establish against the given upstream. Use this to limit HTTP/1.1 traffic, since HTTP/1.1 has a request per connection. If not specified, it uses the default value. For example, 1024 for Envoy proxy.MaxPendingRequests
(int: 0)
- The maximum number of requests that will be queued while waiting for a connection to be established. For this configuration to be respected, a L7 protocol must be defined in theprotocol
field. If not specified, it uses the default value. For example, 1024 for Envoy proxy.MaxConcurrentRequests
(int: 0)
- The maximum number of concurrent requests that will be allowed at a single point in time. Use this to limit HTTP/2 traffic, since HTTP/2 has many requests per connection. For this configuration to be respected, a L7 protocol must be defined in theprotocol
field. If not specified, it uses the default value. For example, 1024 for Envoy proxy.
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 on which the ingress listener should receive traffic. The port will be bound to the IP address that was specified in the-address
flag when starting the gateway. Note: The ingress listener port must not conflict with the health check port specified in the-address
flag.Protocol
(string: "tcp")
- The protocol associated with the listener. One oftcp
,http
,http2
, orgrpc
.Services
(array<IngressService>: <optional>)
- A list of services to be exposed via this listener. Fortcp
listeners, only a single service is allowed. Each service must have a unique name. A namespace is also required for Consul Enterprise.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 listeners with protocoltcp
.Namespace
(string: "")
Enterprise - The namespace from which to resolve the service if different than the existing namespace. The current namespace is used if unspecified.Partition
(string: "")
Enterprise - The admin partition from which to resolve the service if different than the existing partition. The current partition is used if unspecified.Hosts
(array<string>: <optional>)
- A list of hosts that specify what requests will match this service. This cannot be used with atcp
listener, and cannot be specified alongside a*
service name. If not specified, the default domain
will be used to match services. Requests must send the correct host to be routed to the defined service..ingress.*
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, whileexample.*
and*-suffix.example.com
are not.RequestHeaders
(HTTPHeaderModifiers: <optional>)
- A set of HTTP-specific header modification rules that will be applied to requests routed to this service. This cannot be used with atcp
listener.ResponseHeaders
(HTTPHeaderModifiers: <optional>)
- A set of HTTP-specific header modification rules that will be applied to responses from this service. This cannot be used with atcp
listener.TLS
(ServiceTLSConfig: <optional>)
- TLS configuration for this service.SDS
(SDSConfig: <optional>)
- Defines a set of parameters that configures the SDS source for the certificate for this specific service. At least one custom host must be specified inHosts
. The certificate retrieved from SDS will be served for all requests identifying one of theHosts
values in the TLS Server Name Indication (SNI) header.ClusterName
(string)
- The SDS cluster name to connect to to retrieve certificates. This cluster must be specified in the Gateway's bootstrap configuration.CertResource
(string)
- The SDS resource name to request when fetching the certificate from the SDS service.
MaxConnections
(int: 0)
- overrides for theDefaults
fieldMaxPendingRequests
(int: 0)
- overrides for theDefaults
fieldMaxConcurrentRequests
(int: 0)
- overrides for theDefaults
field
TLS
(TLSConfig: <optional>)
- TLS configuration for this listener.Enabled
(bool: false)
- Set this configuration totrue
to enable built-in TLS for this listener.
If TLS is enabled, then each host defined in each service'sHosts
field will be added as a DNSSAN to the gateway's x509 certificate. Note that even hosts from other listeners with TLS disabled will be added. TLS can not be disabled for individual listeners if it is enabled on the gateway.TLSMinVersion
(string: "")
- Set the minimum TLS version supported for this listener. One ofTLS_AUTO
,TLSv1_0
,TLSv1_1
,TLSv1_2
, orTLSv1_3
. If unspecified, Envoy v1.22.0 and newer will default to TLS 1.2 as a min version, while older releases of Envoy default to TLS 1.0.TLSMaxVersion
(string: "")
- Set the maximum TLS version supported for this listener. Must be greater than or equal toTLSMinVersion
. One ofTLS_AUTO
,TLSv1_0
,TLSv1_1
,TLSv1_2
, orTLSv1_3
.CipherSuites
(array<string>: <optional>)
- Set the list of TLS cipher suites to support when negotiating connections using TLS 1.2 or earlier. If unspecified, Envoy will use a default server cipher list. The list of supported cipher suites can seen inconsul/types/tls.go
and is dependent on underlying support in Envoy. Future releases of Envoy may remove currently-supported but insecure cipher suites, and future releases of Consul may add new supported cipher suites if any are added to Envoy.SDS
(SDSConfig: <optional>)
- Defines a set of parameters that configures the listener to load TLS certificates from an external SDS service. See SDS for more details on usage.
SDS properties set here will be used as defaults for all services on this listener.ClusterName
(string)
- The SDS cluster name to connect to to retrieve certificates. This cluster must be specified in the Gateway's bootstrap configuration.CertResource
(string)
- The SDS resource name to request when fetching the certificate from the SDS service.