A Ruby client for the NATS messaging system.
This gem and the client are known to work on the following Ruby platforms:
- MRI 1.9, 2.0, 2.1
- JRuby 1.6.8 (experimental)
Note: This installation installs a version of the NATS server written in Ruby that has been deprecated. Please utilize a supported server such as gnatsd. nats-server will be removed in a future release.
[sudo] gem install nats
== or ==
[sudo] rake geminstall
nats-sub foo &
nats-pub foo 'Hello World!'
require "nats/client"
NATS.start do
# Simple Subscriber
NATS.subscribe('foo') { |msg| puts "Msg received : '#{msg}'" }
# Simple Publisher
NATS.publish('foo.bar.baz', 'Hello World!')
# Unsubscribing
sid = NATS.subscribe('bar') { |msg| puts "Msg received : '#{msg}'" }
NATS.unsubscribe(sid)
# Requests
NATS.request('help') { |response| puts "Got a response: '#{response}'" }
# Replies
NATS.subscribe('help') { |msg, reply| NATS.publish(reply, "I'll help!") }
# Stop using NATS.stop, exits EM loop if NATS.start started the loop
NATS.stop
end
# "*" matches any token, at any level of the subject.
NATS.subscribe('foo.*.baz') { |msg, reply, sub| puts "Msg received on [#{sub}] : '#{msg}'" }
NATS.subscribe('foo.bar.*') { |msg, reply, sub| puts "Msg received on [#{sub}] : '#{msg}'" }
NATS.subscribe('*.bar.*') { |msg, reply, sub| puts "Msg received on [#{sub}] : '#{msg}'" }
# ">" matches any length of the tail of a subject and can only be the last token
# E.g. 'foo.>' will match 'foo.bar', 'foo.bar.baz', 'foo.foo.bar.bax.22'
NATS.subscribe('foo.>') { |msg, reply, sub| puts "Msg received on [#{sub}] : '#{msg}'" }
# All subscriptions with the same queue name will form a queue group
# Each message will be delivered to only one subscriber per queue group, queuing semantics
# You can have as many queue groups as you wish
# Normal subscribers will continue to work as expected.
NATS.subscribe(subject, :queue => 'job.workers') { |msg| puts "Received '#{msg}'" }
NATS.start(:servers => ['nats://127.0.0.1:4222', 'nats://127.0.0.1:4223'] do |c|
puts "NATS is connected to #{c.connected_server}"
c.on_reconnect do
puts "Reconnected to server at #{c.connected_server}
end
end
opts = {
:dont_randomize_servers => true,
:reconnect_time_wait => 0.5,
:max_reconnect_attempts = 10,
:servers => ['nats://127.0.0.1:4222', 'nats://127.0.0.1:4223', 'nats://127.0.0.1:4224]
}
NATS.connect(opts) do |c|
puts "NATS is connected!"
end
# Publish with closure, callback fires when server has processed the message
NATS.publish('foo', 'You done?') { puts 'msg processed!' }
# Timeouts for subscriptions
sid = NATS.subscribe('foo') { received += 1 }
NATS.timeout(sid, TIMEOUT_IN_SECS) { timeout_recvd = true }
# Timeout unless a certain number of messages have been received
NATS.timeout(sid, TIMEOUT_IN_SECS, :expected => 2) { timeout_recvd = true }
# Auto-unsubscribe after MAX_WANTED messages received
NATS.unsubscribe(sid, MAX_WANTED)
# Multiple connections
NATS.subscribe('test') do |msg|
puts "received msg"
NATS.stop
end
# Form second connection to send message on
NATS.connect { NATS.publish('test', 'Hello World!') }
See examples and benchmarks for more information..
(The MIT License)
Copyright (c) 2010-2014 Derek Collison
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.