Service Discovery overview

Last update: Feb 13, 2019

Service discovery enables clients to detect and locate services on your enterprise network automatically. Instead of defining a static list of IPs or hostnames pointing to your backends, you can use a service discovery provider and let KrakenD interact with it to get the hosts dynamically.

Static resolution

The static resolution is the default service discovery choice. It uses a list of hosts declared in the configuration file and KrakenD must be able to reach them directly by hostname, DNS or IP. All the necessary connections are load balanced between all the servers in the list.

Using "sd": "static" in the configuration file is optional.

"backend": [
	{
		"url_pattern": "/some-url",
		"sd": "static",
		"host": [
			"http://my-service-01.api.com:9000",
			"http://my-service-02.api.com:9000"
		]
	}
]

DNS SRV

A typical Service Discovery integration for KrakenD is to use DNS SRV. It is a market standard used by many other systems work such as Kubernetes, Mesos, Haproxy, Nginx plus, AWS ECS, Linkerd, and more.

The most typical setup is KrakenD + Consul (see standard lookup).

See DNS SRV service discovery

etcd

KrakenD can watch the values of the keys in an etcd installation and reconfigure itself when they change.

The integration with etcd allows you to set up your distributed key-value store and configure details such as the timeouts, keep-alive, and certificates.

See etcd service discovery

Eureka

There is support for the Netflix Eureka client. The package is an open source contribution via Schibsted engineers.

See Eureka service discovery