A route allows developers to expose services through an HTTP(S) aware load balancing and proxy layer via a public DNS entry. The route may further specify TLS options and a certificate, or specify a public CNAME that the router should also accept for HTTP and HTTPS traffic. An administrator typically configures their router to be visible outside the cluster firewall, and may also add additional security, caching, or traffic controls on the service content. Routers usually talk directly to the service endpoints.
RouteSpec describes the hostname or path the route exposes, any security information, and one to four backends (services) the route points to. Requests are distributed among the backends depending on the weights assigned to each backend. When using roundrobin scheduling the portion of requests that go to each backend is the backend weight divided by the sum of all of the backend weights. When the backend has more than one endpoint the requests that end up on the backend are roundrobin distributed among the endpoints. Weights are between 0 and 256 with default 1. Weight 0 causes no requests to the backend. If all weights are zero the route will be considered to have no backends and return a standard 503 response.
RouteTargetReference specifies the target that resolve into endpoints. Only the ‘Service’ kind is allowed. Use ‘weight’ field to emphasize one over others.