Mesh gateway, or multi-cluster gateways, is the Consul primitive that allows you to bridge traffic between two or more completely separate Consul service meshes securely and transparently across different network environments. The configuration for the service mesh needs to be written only in one location, and it gets federated and copied automatically to the other locations.
The gateway acts as a bridge between two locations: if one service wants to communicate to another service in another location, it does so through lightweight Envoy proxies. These proxies have no way of decrypting traffic, so the traffic between the services in two locations is done through the mTLS flowing through two gateways. Consul uses SNI headers inside HTTPS requests so the gateway can determine where to send the traffic.
To enable a service so that it can use the mesh gateway, the service...