envoy-eds-server

Intro

Envoy EDS server is a working Envoy Discovery Service implementation. It stores in memory an upstream host list and allows any upstream host to register and reregister.

Internally, envoy-eds-server starts two servers:

• a gRPC server that is invoked by Envoy to fetch the list of upstream hosts.
• a HTTP REST API server where a new host self-registers and deregisters when graceful shutdown happens.

As a good practice, the upstream host should invoke the registration on the REST API server periodically, like a heartbeat.

Future plan:

• add expiration for an upstream host so that if the heartbeat call is not received then after a while the upstream host becomes evicted.