Ingress gateways

Ingress gateways define an entry point into your Istio mesh for incoming traffic.

You can configure gateways using the Gateway and VirtualService custom resources of Istio, and the IstioMeshGateway CR of Service Mesh Manager.

• The Gateway resource describes the port configuration of the gateway deployment that operates at the edge of the mesh and receives incoming or outgoing HTTP/TCP connections. The specification describes a set of ports that should be exposed, the type of protocol to use, TLS configuration – if any – of the exposed ports, and so on. For more information about the gateway resource, see the Istio documentation.
• The VirtualService resource defines a set of traffic routing rules to apply when a host is addressed. Each routing rule defines matching criteria for the traffic of a specific protocol. If the traffic matches a routing rule, then it is sent to a named destination service defined in the registry. For example, it can route requests to different versions of a service or to a completely different service than was requested. Requests can be routed based on the request source and destination, HTTP paths and header fields, and weights associated with individual service versions. For more information about VirtualServices, see the Istio documentation.
• Service Mesh Manager provides a custom resource called IstioMeshGateway and uses a separate controller to reconcile gateways, allowing you to use multiple gateways in multiple namespaces. That way you can also control who can manage gateways, without having permissions to modify other parts of the Istio mesh configuration.

Using IstioMeshGateway, you can add Istio ingress or egress gateways in the mesh and configure them. When you create a new IstioMeshGateway CR, Service Mesh Manager takes care of configuring and reconciling the necessary resources, including the Envoy deployment and its related Kubernetes service.

Note: Service Mesh Manager automatically creates an ingress gateway called smm-ingressgateway and an istio-meshexpansion-cp-v115x. The smm-ingressgateway serves as the main entry point for the services of Service Mesh Manager, for example, the dashboard and the API, while the meshexpansion gateway is used in multi-cluster setups to ensure communication between clusters for the Istio control plane and the user services.

Do not use this gateway for user workloads, because it is managed by Service Mesh Manager, and any change to its port configuration will be overwritten. Instead, create a new mesh gateway using the IstioMeshGateway custom resource.

Service Mesh Manager provides gateway management and observability, allowing you to:

• View the configuration of every gateway.
• Monitor the upstream traffic.
• Manage the port and host configurations.
• Manage routing and traffic.
• Configure TLS settings on the gateway, including cert-manager and Let’s Encrypt setup.

For details on how to set up gateways using Service Mesh Manager, Gateways.