Server Sent Events (SSE) Server with Ruby

sse_server.rb

# Server Sent Events (SSE) Server sample
# refs. https://gist.github.com/rkh/1476463

require 'sinatra'
require 'thin'

set :bind, '0.0.0.0'
set :port, 8080
connections = []

get '/subscribe', provides: 'text/event-stream' do
  stream(:keep_open) do |out|
    connections << out
    out.callback { connections.delete(out) }
  end
end

get '/publish' do
  connections.each { |out| out << "data: #{params[:m]}\n\n" }
  204 # HTTP 204 No Content
end