Service Discovery

Consul makes it simple for services to register themselves and to discover other services via a DNS or HTTP interface. Register external services such as SaaS providers, as well.

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. Look up services in other datacenters, or keep the request local.

Key/Value Storage

Flexible key/value store for dynamic configuration, feature flagging, coordination, leader election and more. Long poll for near-instant notification of configuration changes.

DNS Query Interface

Look up services using Consul's built-in DNS server. Support existing infrastructure without any code change.

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": "bar"

}

]