Skip to content
Ruby client for NATS, the cloud native messaging system.
Branch: master
Clone or download
Fetching latest commit…
Cannot retrieve the latest commit at this time.
Permalink
Type Name Latest commit message Commit time
Failed to load latest commit information.
benchmark
examples
lib/nats
scripts
spec
.travis.yml
GOVERNANCE.md
Gemfile
Gemfile.lock
LICENSE
MAINTAINERS.md
README.md
Rakefile
TODO.md
nats-pure.gemspec

README.md

NATS - Pure Ruby Client

A thread safe Ruby client for the NATS messaging system written in pure Ruby.

License Apache 2.0Build StatusGem Version

Getting Started

gem install nats-pure

Basic Usage

require 'nats/io/client'

nats = NATS::IO::Client.new

nats.connect(:servers => ["nats://127.0.0.1:4222"])
puts "Connected to #{nats.connected_server}"

# Simple subscriber
nats.subscribe("foo.>") { |msg, reply, subject| puts "Received on '#{subject}': '#{msg}'" }

# Simple Publisher
nats.publish('foo.bar.baz', 'Hello World!')

# Unsubscribing
sid = nats.subscribe('bar') { |msg| puts "Received : '#{msg}'" }
nats.unsubscribe(sid)

# Requests with a block handles replies asynchronously
nats.request('help', 'please', max: 5) { |response| puts "Got a response: '#{response}'" }

# Replies
nats.subscribe('help') do |msg, reply, subject|
  puts "Received on '#{subject}': '#{msg}'"
  nats.publish(reply, "I'll help!")
end

# Request without a block waits for response or timeout
begin
  msg = nats.request('help', 'please', timeout: 0.5)
  puts "Received on '#{msg.subject}': #{msg.data}"
rescue NATS::IO::Timeout
  puts "nats: request timed out"
end

# Server roundtrip which fails if it does not happen within 500ms
begin
  nats.flush(0.5)
rescue NATS::IO::Timeout
  puts "nats: flush timeout"
end

# Closes connection to NATS
nats.close

Clustered Usage

require 'nats/io/client'

nats = NATS::IO::Client.new

nats.on_error do |e|
  puts "Error: #{e}"
end

nats.on_reconnect do
  puts "Reconnected to server at #{nats.connected_server}"
end

nats.on_disconnect do
  puts "Disconnected!"
end

nats.on_close do
  puts "Connection to NATS closed"
end

cluster_opts = {
  servers: ["nats://127.0.0.1:4222", "nats://127.0.0.1:4223"],
  dont_randomize_servers: true,
  reconnect_time_wait: 0.5,
  max_reconnect_attempts: 2
}

nats.connect(cluster_opts)
puts "Connected to #{nats.connected_server}"

nats.subscribe("hello") do |data|
  puts "#{Time.now} - Received: #{data}"
end

n = 0
loop do
  n += 1
  nats.publish("hello", "world.#{n}")
  sleep 0.1
end

TLS

It is possible to setup a custom TLS connection to NATS by passing an OpenSSL context to the client to be used on connect:

tls_context = OpenSSL::SSL::SSLContext.new
tls_context.ssl_version = :TLSv1_2

nats.connect({
   servers: ['tls://127.0.0.1:4444'],
   reconnect: false,
   tls: {
     context: tls_context
   }
 })

License

Unless otherwise noted, the NATS source files are distributed under the Apache Version 2.0 license found in the LICENSE file.

You can’t perform that action at this time.