Etcd

A crystal client for etcd. Heavily inspired from the ruby etcd client.

ONLY support etcd API v2 version, it means you need run etcd --enable-v2=true in etcd 3.0+ version.

Installation

Add this to your application's shard.yml:

dependencies:
  etcd:
    github: kuende/etcd-crystal

Usage

Create a client object

require "etcd"

client = Etcd.client # this will create a client against etcd server running on localhost on port 2379
client = Etcd.client("localhost:2379")
client = Etcd.client do |config|
  config.user_name = "foo"
  config.password = "bar"
end
client = Etcd.client("localhost:2379") do |config|
  config.user_name = "foo"
  config.password = "bar"
end

Set a key

client.set("/nodes/n1", {:value => "1"})
# with ttl
client.set("/nodes/n2", {:value => "2", :ttl => "4"})  # sets the ttl to 4 seconds

Get a key

client.get("/nodes/n2").value

Delete a key

client.delete("/nodes/n1")
client.delete("/nodes/", {:recursive => true})

Compare and swap

client.compare_and_swap("/nodes/n2", {:value => "2", :prevValue => "4"}) # will set /nodes/n2 's value to 2 only if its previous value was 4

Watch a key

client.watch("/nodes/n1") # will wait till the key is changed, and return once its changed
client.watch("/nodes/n1", Etcd::Options.new, 3) # watch a key with timeout

client.watch("/nodes/n1", {:recursive => true}) # watch a directory recursive
client.watch("/nodes/n1", {:recursive => true}, 3) # watch a directory recursive with timeout