Discovery

A key component of a microservice architecture is how services “discover” each other.

As each service exposes its API (generally using HTTP), it is bound to an IP and a port. Other services must know this address to contact the service and retrieve information from it. This is generally done by keeping a dedicated “registry”, whose IP and port are known by all services, and to which each service declares itself at run time. Contacting a service is then done by asking the registry a list of available instances of this service running on the various cluster nodes.

Pydio Cells uses Micro, a golang-based microservice framework that provides various adapters to common registry solutions. Nats.io is a well known solution providing such a registry solution. Pydio Cells uses Nats by default, and actually embeds a Nats server to avoid any deployment hassle.

In the future, Pydio Cells could use etcd or other kubernetes-like feature for services registry.