Service Discovery

Consul makes it simple for services to register themselves, and to discover other services via a DNS or HTTP interface.

Failure Detection

Pairing service discovery with health checking prevents routing requests to unhealthy hosts, and enables services to easily provide circuit breakers.

Multi Datacenter

Consul scales to multiple datacenters out of the box, with no complicated configuration.

Shared Configuration

Store hierarchical key/value configuration data for services and get notified when any of these values change.

DNS Query Interface

Look up services using Consul's built-in DNS server. This avoids the need for a Consul-specific client in any of your services.

Terminal

admin@hashicorp: dig web-frontend.service.consul. ANY

; <<>> DiG 9.8.3-P1 <<>> web-frontend.service.consul. ANY

;; global options: +cmd

;; Got answer:

;; ->>HEADER<<- opcode: QUERY, status: NOERROR, id: 29981

;; flags: qr aa rd ra; QUERY: 1, ANSWER: 2, AUTHORITY: 0, ADDITIONAL: 0

;; QUESTION SECTION:

;web-frontend.service.consul. IN ANY

;; ANSWER SECTION:

web-frontend.service.consul. 0 IN A 10.0.3.83

web-frontend.service.consul. 0 IN A 10.0.1.109

admin@hashicorp:

Key Value Storage

Consul provides a flexible, hierarchical key/value store accessible via a simple HTTP API. This data is replicated across multiple servers and is highly available. Other HTTP APIs let you long poll for changes to a key.

Terminal

admin@hashicorp: curl -X PUT -d 'bar' http://localhost:8500/v1/kv/foo

true

admin@hashicorp: curl http://localhost:8500/v1/kv/foo

[

{

"CreateIndex": 100,

"ModifyIndex": 200,

"Key": "foo",

"Flags": 0,

"Value": "aGVsbG8gd29ybGQK=="

}

]