async requests using sinatra streaming API - ruby

I use async_sinatra gem to implement asynchronous routes, but I came across a post somewhere that said that Sinatra's streaming API can be used instead of async_sinatra for this purpose. Can the same functionality as below be implemented using streaming?
require 'em-hiredis'
require 'sinatra/async'
class App < Sinatra::Base
register Sinatra::Async
def redis
#redis ||= EM::Hiredis.connect
end
aget '/' do
redis.blpop('abcdef', 15).
callback {|x| body "x=#{x}"}.
errback {|e| body "e=#{e}"}
end
run! if app_file == $0
end

to answer my own question:
require 'em-hiredis'
require 'sinatra/base'
class App < Sinatra::Base
def redis
#redis ||= EM::Hiredis.connect
end
get '/' do
stream :keep_open do |out|
redis.blpop('abcdef', 15).callback do |x|
out << "x=#{x}"
out.close
end.errback do |e|
out << "e=#{e}"
out.close
end
end
end
run! if app_file == $0
end

Related

How to test if some specific rack middleware is being used?

To be more particular, I'm talking about sentry-raven and sinatra here. I saw examples testing sinatra applications, or middlewares. But I didn't see ones testing if some particular middleware is present. Or should I be testing behavior, not configuration (or how should I call it)?
The important thing (I'd say) is the behaviour, but if you wish to check for middleware there are 2 ways I'd suggest after taking a delve into the Sinatra source (there are possibly much easier/better ways):
The env
In the Sinatra source there's a method that uses the env to check if a middleware is already present:
# Behaves exactly like Rack::CommonLogger with the notable exception that it does nothing,
# if another CommonLogger is already in the middleware chain.
class CommonLogger < Rack::CommonLogger
def call(env)
env['sinatra.commonlogger'] ? #app.call(env) : super
end
You could do the same thing in a route, e.g.
get "/env-keys" do
env.keys.inspect
end
It'll only show you the middleware if it's inserted something in env hash, e.g.
class MyBad
def initialize app, options={}
#app = app
#options = options
end
def call env
#app.call env.merge("mybad" => "I'm sorry!")
end
end
output:
["SERVER_SOFTWARE", "SERVER_NAME", "rack.input", "rack.version", "rack.errors", "rack.multithread", "rack.multiprocess", "rack.run_once", "REQUEST_METHOD", "REQUEST_PATH", "PATH_INFO", "REQUEST_URI", "HTTP_VERSION", "HTTP_HOST", "HTTP_CONNECTION", "HTTP_CACHE_CONTROL", "HTTP_ACCEPT", "HTTP_USER_AGENT", "HTTP_DNT", "HTTP_ACCEPT_ENCODING", "HTTP_ACCEPT_LANGUAGE", "GATEWAY_INTERFACE", "SERVER_PORT", "QUERY_STRING", "SERVER_PROTOCOL", "rack.url_scheme", "SCRIPT_NAME", "REMOTE_ADDR", "async.callback", "async.close", "rack.logger", "mybad", "rack.request.query_string", "rack.request.query_hash", "sinatra.route"]
It's near the end of that list.
The middleware method
There's also a method called middleware in Sinatra::Base:
# Middleware used in this class and all superclasses.
def middleware
if superclass.respond_to?(:middleware)
superclass.middleware + #middleware
else
#middleware
end
end
Call it in the class definition of a modular app and you can get the middlewares in an array:
require 'sinatra/base'
class AnExample < Sinatra::Base
use MyBad
warn "self.middleware = #{self.middleware}"
output:
self.middleware = [[MyBad, [], nil]]
There may be a way to get it from Sinatra::Application, but I haven't looked.
With help from ruby-raven guys, we've got this:
ENV['RACK_ENV'] = 'test'
# the app: start
require 'sinatra'
require 'sentry-raven'
Raven.configure(true) do |config|
config.dsn = '...'
end
use Raven::Rack
get '/' do
'Hello, world!'
end
# the app: end
require 'rspec'
require 'rack/test'
Raven.configure do |config|
logger = ::Logger.new(STDOUT)
logger.level = ::Logger::WARN
config.logger = logger
end
describe 'app' do
include Rack::Test::Methods
def app
#app || Sinatra::Application
end
class TestRavenError < StandardError; end
it 'sends errors to sentry' do
#app = Class.new Sinatra::Application do
get '/' do
raise TestRavenError
end
end
allow(Raven.client).to receive(:send).and_return(true)
begin
get '/'
rescue TestRavenError
end
expect(Raven.client).to have_received(:send)
end
end
Or if raven sending requests is in the way (when tests fail because of raven sending requests, and not because of the underlying error), one can disable them:
Raven.configure(true) do |config|
config.should_send = Proc.new { false }
end
And mock Raven.send_or_skip instead:
...
allow(Raven).to receive(:send_or_skip).and_return(true)
begin
get '/'
rescue TestRavenError
end
expect(Raven).to have_received(:send_or_skip)
...

Sinatra + Fibers + EventMachine

I would like to know to to pause a Root Fiber in ruby (if possible).
I have this Sinatra app, and I am making async calls to an external API with EventMachine.
I don't want to respond to the client until the api responds me.
For example, sleeping the Root Fiber in Sinatra until the EventMachine callback wake it up.
Thanks.
get '/some/route/' do
fib = Fiber.current
req = EM::SomeNonBlokingLib.request
req.callback do |response|
fib.resume(response)
end
req.errback do |err|
fib.resume(err)
end
Fiber.yield
end
EDIT
In your case you should spawn a Fiber for each request. So. Firstly create Rack config file and add some magick:
# config.ru
BOOT_PATH = File.expand_path('../http.rb', __FILE__)
require BOOT_PATH
class FiberSpawn
def initialize(app)
#app = app
end
def call(env)
fib = Fiber.new do
res = #app.call(env)
env['async.callback'].call(res)
end
EM.next_tick{ fib.resume }
throw :async
end
end
use FiberSpawn
run Http
Then your http Sinatra application:
# http.rb
require 'sinatra'
require 'fiber'
class Http < Sinatra::Base
get '/' do
f = Fiber.current
EM.add_timer(1) do
f.resume("Hello World")
end
Fiber.yield
end
end
Now you could run it under thin for example:
> thin start -R config.ru
Then if you will visit locakhost:3000 you'll see your Hello World message

Modular Sinatra App using Sinatra Reloader?

Hi if I had a 'main' sinatra file with the following code,
require 'sinatra'
require "sinatra/reloader"
class MyApp < Sinatra::Base
configure do
require "./rest/auth.rb"
register Sinatra::Reloader
also_reload '/rest/auth'
end
get '/' do
erb :home
end
end
And I wanted to put my authentication logic inside of /rest/auth.rb, how can I get /rest/auth.rb to reload in development mode? Must I put the configure block and require sinatra/reloader in every one of my controller files? I'd like for my controllers to inherit the settings of my main class. The code inside of auth.rb is as follows:
class MyApp < Sinatra::Base
set(:auth) do |*roles| # <- notice the splat here
condition do
unless logged_in?
session[:success_url] = request.path_info
redirect '/'
end
end
end
def logged_in?
current_user
end
def current_user
if session[:user_id]
u = User.find(:id=>"#{session[:user_id]}")
else
false
end
end
end
I need to restart the server for my changes to take place but I can throw that reload code in auth.rb's configure block though I wouldn't like to. Any ideas?
Try to rewrite like this
require 'sinatra/base'
require "sinatra/reloader"
class MyApp < Sinatra::Base
configure :development do
register Sinatra::Reloader
also_reload './rest/auth'
end
require "./rest/auth.rb"
get '/' do
erb :home
end
end

stream multiple body using async sinatra

I would like start a long poll request from javascript which is fine and i expect my ruby prog to stream multiple body sections to the javascript. Why doesn the following (pseudo)code work?
require 'rubygems'
require 'sinatra/async'
require 'eventmachine'
require 'thin'
require 'json'
class Test < Sinatra:Base
register Sinatra::Async
aget '/process' do
for c in 1..10
body {
{ :data => [ "this is part #{c}" ] }.to_json
end
end
end
run!
end
Maybe i misunderstood what long polling and async is supposed to do, but my expectation is that i get multiple bodies sent back to the client ? Do i need to use eventmachine or something?
thanks
require 'rubygems'
require 'sinatra/async'
require 'thin'
require 'json'
class Test < Sinatra::Base
register Sinatra::Async
class JSONStream
include EventMachine::Deferrable
def stream(object)
#block.call object.to_json + "\n"
end
def each(&block)
#block = block
end
end
aget '/process' do
puts 'ok'
out = JSONStream.new
body out
EM.next_tick do
c = 0
timer = EM.add_periodic_timer(0.3) do
c += 1
out.stream :data => ["this is part #{c}"]
if c == 100
timer.cancel
out.succeed
end
end
end
end
run!
end
See also: http://confreaks.net/videos/564-scotlandruby2011-real-time-rack
It appears in the example below that you need an EventMachine event to trigger the sending of the multiple bodies. Also see this previous answer as well.
require 'sinatra/async'
class AsyncTest < Sinatra::Base
register Sinatra::Async
aget '/' do
body "hello async"
end
aget '/delay/:n' do |n|
EM.add_timer(n.to_i) { body { "delayed for #{n} seconds" } }
end
end

How mix in routes in Sinatra for a better structure

I found nothing about how I can mix-in routes from another module, like this:
module otherRoutes
get "/route1" do
end
end
class Server < Sinatra::Base
include otherRoutes
get "/" do
#do something
end
end
Is that possible?
You don't do include with Sinatra. You use extensions together with register.
I.e. build your module in a separate file:
require 'sinatra/base'
module Sinatra
module OtherRoutes
def self.registered(app)
app.get "/route1" do
...
end
end
end
register OtherRoutes # for non modular apps, just include this file and it will register
end
And then register:
class Server < Sinatra::Base
register Sinatra::OtherRoutes
...
end
It's not really clear from the docs that this is the way to go for non-basic Sinatra apps. Hope it helps others.
You could do this:
module OtherRoutes
def self.included( app )
app.get "/route1" do
...
end
end
end
class Server < Sinatra::Base
include OtherRoutes
...
end
Unlike Ramaze, Sinatra's routes are not methods, and so cannot use Ruby's method lookup chaining directly. Note that with this you can't later monkey-patch OtherRoutes and have the changes reflected in Server; this is just a one-time convenience for defining the routes.
I prefer the use of sinatra-contrib gem to extend sinatra for cleaner syntax and shared namespace
# Gemfile
gem 'sinatra', '~> 1.4.7'
gem 'sinatra-contrib', '~> 1.4.6', require: 'sinatra/extension'
# other_routes.rb
module Foo
module OtherRoutes
extend Sinatra::Extension
get '/some-other-route' do
'some other route'
end
end
end
# app.rb
module Foo
class BaseRoutes < Sinatra::Base
get '/' do
'base route'
end
register OtherRoutes
end
end
sinata-contrib is maintained alongside the sinatra project
Well you can also use the map method to map routes to your sinatra apps
map "/" do
run Rack::Directory.new("./public")
end
map '/posts' do
run PostsApp.new
end
map '/comments' do
run CommentsApp.new
end
map '/users' do
run UserssApp.new
end
Just my two cents:
my_app.rb:
require 'sinatra/base'
class MyApp < Sinatra::Base
set :root, File.expand_path('../', __FILE__)
set :app_file, __FILE__
disable :run
files_to_require = [
"#{root}/app/helpers/**/*.{rb}",
"#{root}/app/routes/**/*.{rb}"
]
files_to_require.each {|path| Dir.glob(path, &method(:require))}
helpers App::Helpers
end
app/routes/health.rb:
MyApp.configure do |c|
c.before do
content_type "application/json"
end
c.get "/health" do
{ Ruby: "#{RUBY_VERSION}",
Rack: "#{Rack::VERSION}",
Sinatra: "#{Sinatra::VERSION}"
}.to_json
end
end
app/helpers/application.rb:
module App
module Helpers
def t(*args)
::I18n::t(*args)
end
def h(text)
Rack::Utils.escape_html(text)
end
end
end
config.ru:
require './my_app.rb'

Resources