Passing headers (or other settings) from Sinatra through Puma - ruby

I am trying to learn how to develop a simple web app using pure Ruby. I have a simple backend service which I created as a Sinatra app. While developing it, I noticed the frontend (a simple HTML/JS static site) would not communicate with it because of CORS policies. So I looked into how to pass headers from Sinatra.
I came across sinatra-cors. I set it up as instructed and my app looks like this (abbreviated):
require 'sinatra'
require 'sinatra/cors'
set :allow_origin, '*'
set :allow_methods, 'GET,HEAD,POST'
set :allow_headers, 'content-type,if-modified-since,access-control-allow-methods,access-control-allow-origin'
set :expose_headers, 'content-disposition'
set :allow_credentials, true
post '/' do
[...]
end
When I run it with ruby app.rb, it works perfectly. Frontend can communicate and CORS policies are observed.
Now, I want to set up the service for a production environment. For that, I want to use Puma. So with Puma, I have a config.ru which looks like this:
require File.expand_path('app', File.dirname(__FILE__))
run WebApp
and I modified my app.rb to look like this (again abbreviated):
require 'sinatra'
require 'sinatra/cors'
class WebApp < Sinatra::Application
set :allow_origin, '*'
set :allow_methods, 'GET,HEAD,POST'
set :allow_headers, 'content-type,if-modified-since,access-control-allow-methods,access-control-allow-origin'
set :expose_headers, 'content-disposition'
set :allow_credentials, true
post '/' do
[...]
end
end
basically, wrapped the app in a class, and call it from the config.ru. When I run this by running puma in the directory, the service comes up, but headers are no longer passed back. Whenever I try to hit the backend, I get:
Access to XMLHttpRequest at 'http://localhost:4567/' from origin 'null' has been blocked by CORS policy: Response to preflight request doesn't pass access control check: No 'Access-Control-Allow-Origin' header is present on the requested resource.
This was the error I was getting before I originally set up the headers. So it seems pretty clear to me that the set parameters are being ignored.
So, this seems like a simple matter, but I have not been able to find a proper answer: How do I make Puma respect the 'set' parameters? Or alternatively, how do I achieve the same desired result?
It seems clear to me that I am missing a very simple thing, but I cannot figure out what exactly it is.
Thanks in advance!

It looks like you are just missing register Sinatra::Cors in your class.
class WebApp < Sinatra::Application
register Sinatra::Cors # Add this line.
set :allow_origin, '*'
# etc.

Related

Modular Sinatra app returns 404's under Passenger

I have a modular Sinatra app which runs fine when executed with rackup. The config.ru file is defined as follows:
map '/' do
run My::Controllers::Default
end
map '/api' do
run My::Controllers::Api
end
When I run the app under nginx/passenger I get nothing but 404's, even for the '/' route. Suspecting that something was wrong with routing, I modified config.ru as follows:
run My::Controllers::Default
After restarting nginx, I was served the default page of the app. However, the default page of the app reaches into the api route to get some documentation to display, and that part returns a 404. Given that config.ru is able to run the Default controller, I'm sure that the issue has nothing to do with being able to load all of the relevant ruby files--which seems to be the problem in other related questions I've found on SO.
With that in mind I modified config.ru as follows:
map '/api' do
run My::Controllers::Api
end
run My::Controllers::Default
At this point I'm back to getting nothing but 404's, even for the '/' route. It seems that the map statement is confusing the webserver and making it unable to find the correct routes.
If I just run the app using rackup everything behaves as expected, so I'm really at a loss to explain what I'm seeing.
I remember this being the answer. Let me know if it works for you. If it does I'll "Accept" the answer so that others will find it.
Middleware
A bug in passenger prevents it from understanding the map statement in config.ru https://groups.google.com/forum/#!msg/phusion-passenger/PoEEp9YcWbY/1y0QL_i3tHYJ
class PassengerFix
def initialize(app)
#app = app
end
def call(env)
env["SERVER_NAME"] = env["HTTP_HOST"]
return #app.call(env)
end
end
config.ru
configure do
use PassengerFix
end

Simplest method of enforcing HTTPS for Heroku Ruby Sinatra app

I have an app I created on Heroku which is written in Ruby (not rails) and Sinatra.
It is hosted on the default herokuapp domain so I can address the app with both HTTP and HTTPS.
The app requests user credentials which I forward on to an HTTPS call so the forwarding part is secure.
I want to ensure my users always connect securely to my app so the credentials aren't passed in clear text.
Despite lots of research, I've not found a solution to this simple requirement.
Is there a simple solution without changing my app to Ruby rails or otherwise?
Thanks,
Alan
I use a helper that looks like this:
def https_required!
if settings.production? && request.scheme == 'http'
headers['Location'] = request.url.sub('http', 'https')
halt 301, "https required\n"
end
end
I can then add it to any single route I want to force to https, or use it in the before filter to force on a set of urls:
before "/admin/*" do
https_required!
end
Redirect in a Before Filter
This is untested, but it should work. If not, or if it needs additional refinement, it should at least give you a reasonable starting point.
before do
redirect request.url.sub('http', 'https') unless request.secure?
end
See Also
Filters
Request Object
RackSsl::Enforcer

Jekyll site via Sinatra and Heroku - can't route to new posts

I created a 'Hello, World' app using Sinatra and then pushed to Heroku and all worked.
I've since created a basic Jekyll blog, and am trying to access it via Heroku using the following routes:
get '/?' do
file.read("_site/index.html")
end
get '/.*.*' do
file.read("_site/#{params[:splat]}")
end
not_found do
file.read("_site/error/index.html")
end
The route to the index works fine link to my site
but as soon as I click to the first post it always fails.
I have tried so many variations of different routes for the :splat and get, just can't seem to get it to work? Any ideas?
In the route that's failing, before the file.read statement, add warn "splat = #{params[:splat]}" and that will output the result to the terminal, and you can see what it's actually getting, e.g.
get '/.*.*' do
warn "splat = #{params[:splat]}"
file.read("_site/#{params[:splat]}")
end
You could also try using an absolute path to the files, though if you're getting the index page then it suggests it's not needed:
config do
set :statics, File.expand_path(File.join(settings.root, "_site"))
end
get '/.*.*' do
file.read( File.join settings.statics, params[:splat] )
end
Unless there's something else you were planning to use Sinatra's routes for, you could probably remove the Sinatra routes entirely and just make the "_site" folder the public_folder, and then Sinatra will do the serving of the static files for you:
config do
set :public_folder, File.expand_path(File.join(settings.root, "_site"))
end
# no more to do...

Strange issue in Sinatra

ok so this is very strange (well is to me), everything in my master branch works fine, I then created a new branch called twitter to conduct some twitter feed implementation. I have done this and was working yesterday on my linux machine.. I have pulled the branch today in a windows environment but when i load the app i now get the regular Sinatra 404 Sinatra doesn’t know this ditty.
This is my profile.rb file
require 'bundler/setup'
Bundler.require(:default)
require 'rubygems'
require 'sinatra'
require './config/config.rb' if File.exists?('./config/config.rb')
require 'sinatra/jsonp'
require 'twitter'
require 'sinatra/static_assets'
class Profile < Sinatra::Base
helpers Sinatra::Jsonp
enable :json_pretty
register Sinatra::StaticAssets
##twitter_client = Twitter::Client.new(
:consumer_key => ENV["CONSUMER_KEY"],
:consumer_secret => ENV["CONSUMER_SECRET"],
:oauth_token => ENV["OAUTH_TOKEN"],
:oauth_token_secret => ENV["OAUTH_SECRET"],
)
get '/' do
erb :index
end
get '/feed' do
jsonp ##twitter_client.user_timeline('richl14').map(&:attrs)
end
end
Config.ru
require './profile'
run Profile
Does anyone have any ideas of what i need to be looking at to solve this? Can anyone speak from experience with this?
Thanks
When you use the classic Sinatra style you use require 'sinatra' and then add routes to the top level. These routes get added to the Sinatra::Application. When you directly run this file, e.g. with ruby my_app.rb, Sinatra runs a built in web server, which will serve the Sinatra::Application app.
When you use the modular style, you use require 'sinatra/base', and then add routes to your Sinatra::Base subclass. In this case directly executing the file doesn’t start the built in server.
In your case you are using the modular style, but have used require 'sinatra'. You create your Profile app, but when you run the file directly Sinatra launches the built in server and serves the Sinatra::Application app. Since you haven’t added any routes to this (they’ve all been added to Profile) it runs but all requests return 404.
One way to get your app to launch you is to use rackup. This will launch the Profile app that you have explicitly set in your config.ru. (Explicitly starting your webserver will also work, e.g. using thin start).
Another possibility would be to add a line like this to the end of your Profile class:
run! if app_file == $0
This tells Sinatra to start the build in server running the Profile app if the file is the same as the Ruby file being executed, in a similar way to how the classic style app is launched. If you use this method you should change require 'sinatra' to require 'sinatra/base' otherwise you will get two servers launched, one after the other (in fact you should probably make that change anyway).
See the Sinatra docs for more info about the difference between classic and modular style.

How to set HTTP response (cache) headers in a Sinatra app hosted on Heroku

I have a fairly simple app (just one index.html file and a css file - it really is just a static page) hosted on Heroku.
I use Sinatra to host it on Heroku. The 'app' itself is fairly simple:
require 'rubygems'
require 'sinatra'
get "/" do
File.read(File.join('public', 'index.html'))
end
The question is, how do I set the HTTP response header for the static assets? In particular, I wanted to set the Expires header for caching purposes.
EDIT: I'm looking to add the said header to the static assets (ie, the one that resides under /public, like background images, icons, etc)
Apart from the fact that I wouldn't get through the Sinatra stack just to serve static files, you'd call
cache_control :public, max_age: 60
to cache for a minute. cache_control is a helper that comes with Sinatra.
Otherwise, I'd suggest you have a look at http://www.sinatrarb.com/configuration.html to see how Sinatra is set up so you don't have do deal with serving static files.
Hope this helps.
edit: I just saw you were explicitly asking for the Expires header. I'm not sure, but that should be fairly the same way as Cache-Control. Sorry for the confusion
As an expansion to #awendt's answer, Sinatra can actually handle static files with out needing to explicitly define the route and print the file.
By adding:
set :static, true
..you can add your index.html and stylesheet.css to a public/ folder. Then when you visit http://localhost:9292/stylesheet.css you'll be provided with the static file.
If you want to use another folder name, instead of the default public/, then try:
set :public, "your_folder_name"
If we want to be less explicit we can just create the public/ folder in the knowledge that Sinatra will enable :static for us anyway :)
Source: http://www.sinatrarb.com/configuration.html#__enabledisable_static_file_routes

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