Integrating Ruby Handler With Apache - ruby

If you use Webrick you can implement a servlet and service http requests using ruby. Now I have code that does everything that I want but I would like to move to Apache. Is there a way to modify the .htaccess file to send all the requests through a ruby handler?

you should check out phusion passenger. It lets you easily deploy any ruby Rack based web app in apache. You can then use rails, sinatra, waves, etc from apache.

You're asking for mod_ruby.
That was abandoned years ago in favor of running the Ruby code in a separate process under Mongrel, and just using Apache mod_proxy (or another web server acting as a proxy).
And now that Passenger is available lots of people (including myself) are adopting it instead of Mongrel, because it's simpler.
Just accept that you did it wrong the first time and bite the bullet. Rewrite your code as a Rack service, and run it via Passenger.

Related

Front end separated from back end project using Sinatra

I am planning to create a website that has front end and back end. I was wondering how the FE communicates with the BE.
I saw a project that uses Xampp to run the front end and sinatra for the back end. It needs to start apache, then the backend is fired using the rackup command. I assume the backend runs under Webrick.
Can someone explain how these two ends communicate with each other? If there is a good tutorial for this, I will appreciate it.
Sinatra is a popular option for API-only backend applications. We use Grape with Sinatra or just Sinatra without any dependency.
I have two app examples that can help you:
https://github.com/katgironpe/sinatra-grape
https://github.com/katgironpe/simple-sinatra-mvc
Webrick or Puma can be used with Sinatra, but it's not impossible to run a Ruby app on XAMPP. I did that several years ago. The front-end is probably just consuming the Sinatra API.
You can use Ember CLI project. It can get complex with other options like Angular.js and React.js. Or if you like, just use jQuery.

How to run core ruby web application in web server?

I had installed ruby/gem and the server is apache2 running fine.But I try to run a simple ruby project which is built by using Netbeans IDE. How can I run this web project in web browser?
While you sometimes still read that, you should not run ruby applications under CGI. The specification is getting old and support for it (especially in the rails world) is ceasing.
Most web frameworks in ruby use Rack which is a generic interface between a webserver and a ruby application. Thus if you write a rack-compliant application (which you do if you use e.g. Rails, Sinatra or Padrino) you can start it in any Webserver offering a Rack-interface.
The probbly most popular one is Phusion Passenger (modrails) which is a module for either Apache or nginx and integrates into the webserver. It should be noted though that it only runs on Linux/Unix systems, not Windows.
Popular alternatives are Thin and Unicorn. These servers are typically run behind a front-end webserver like Apache or nginx. The frontend-webserver delivers static files (CSS, images, ...) and forwards dynamic requests to the backend-webserver (thin or unicorn). You can find many guides on google if you search for "Apache thin ubuntu" (or similar).
And as a side-note, Mongrel shouldn't be used anymore for new deployments as it isn't really maintained anymore and causes many issues with newer framework versions.

CGI Programming + Ruby

Is there a framework for Ruby for CGI that provides similar functionality as Ruby on Rails (mvc)?
Also, The server where the app shall be used on does not support FCGI, only plain old CGI.
Ruby comes with a CGI module, but it isn't a MVC at all. It makes it easy to extract parameters from a HTTP request passed to the app, encode and decode the query params, etc. It relies on a web server to handle routing the request to the right page, so there's quite a gap between a MVC and a CGI.
There are alternate MVCs for Ruby. Sinatra is very easy to use, and Padrino is built on Sinatra, putting it between Sinatra and Rails. I like using Sinatra at work because it's good for fast prototyping and in-house loads are nowhere close to what we'd get on an internet facing app.
As far as the server not supporting FCGI, a MVC doesn't really care. Put its server on a different port, then reference that port when you want something to talk to Sinatra. For instance, if you tell Sinatra to use 8088, your URLs for Sinatra served pages would be something like: http://host.com:8808/url/path/to/object. Load your Sinatra based app on the web server and start it up. It'll run concurrently with the normal web server.

Ruby Frameworks - Request Entry Point

I'm learning ruby and looking at his frameworks. One things that i can't understand is how frameworks handles requests in ruby world. Digging deeper I found that there's a middleware called Rack that does the job.
So my questions are:
How does Rack handles HTTP request?
Coming from PHP where there's the famous "index.php" file as a entry-point, which is the corrispective in the ruby world?
Thanks in advance.
From the rack specification:
A Rack application is an Ruby object (not a class) that responds to call. It takes exactly one argument, the environment and returns an Array of exactly three values: The status, the headers, and the body.
In pratice, the common way that a rack application is started is defined in a config.ru file. If you look in the base directory of a rails app you will see it. In rails, it includes config/environment.rb, which includes config/application.rb, which includes boot.rb, which includes gems and whatnot. From that point the framework starts to do its thing.
The general idea with rails is that a dispatcher takes any request and decides what needs to be done with it. The dispatcher can be seen as an equivalent to the index.php you mentioned.
How the config.ru file gets accessed (or how the rack app is started) is dependent on the way your application is deployed. Phusion Passenger, a popular module for apache and nginx, will look for config.ru in the root directory of any application you have added to the server config file.
It really comes down to the deployment option. Ruby apps can be run via apache/nginx modules, directly via web servers written in ruby, and via CGI.
Here is a description of the different ways web apps are deployed, from the passenger docs

Ruby (off the Rails) Hosting

Many people have asked about Rails hosting on this site, but I'm not familiar enough with the back end of things to know if there's a difference.
I want to host some Ruby CGI 'webservices', basically just ruby methods that take parameters from a POST request, access a MySQL db and return data.
I've looked at RoR and it seems like overkill for this, from what I can tell it's for speeding up the development of data baesd CRUD sites, which is not at all what I'm doing.
So my question is, does this affect the hosting provider I choose? Does anyone recommend a good Ruby host for CGI operations? I'm not familiar with FastCGI, mod_ruby, Passenger, Mongrel etc. and what they mean for performance, scalability etc. I just want to host my ruby scripts with reasonably good performance, and all the info out there(and here) seems to be focused on rails.
First, if you want lightweight, Sinatra is usually my first pick. Pair it up with rack and Passenger for best results. It's not CGI, but realistically speaking, CGI is rarely a good match-up with Ruby.
Here's the "Hello World!" Sinatra app from the main page:
require 'rubygems'
require 'sinatra'
get '/hi' do
"Hello World!"
end
Hard to get more lightweight than that.
As for providers, anybody that supports Passenger (mod_rack) should be able to handle Sinatra. I'm a big fan of Slicehost personally, but they're a VPS host, which means you need to be able to install and manage the entire stack yourself. If you don't mind paying a tiny bit extra for the infrastructure, Heroku makes installation and deployment dead simple, so long as your needs don't exceed what they provide (sounds like they won't). In the unlikely event that you're only using 5MB or if you're using an external storage mechanism like Amazon RDS, Heroku may actually be free for you.
Update:
Passenger is an Apache module that allows Rack applications to be run inside of Apache.
Rack is a middleware layer that separates the web server and the web framework from each other. This allows web frameworks to run on any web server for which there is an adapter.
Sinatra is a lightweight web framework that runs on top of Rack.
Once Passenger and Rack are installed (gem install rack, gem install passenger) you just need to edit the Apache vhost to point at the config.ru file for your Sinatra app and create the required directories as per the Passenger docs and you'll be good to go.
I think you might want to look into Rack. It allows you to do the kinds of things you're talking about and shrugs off the weight of frameworks like Rails or Merb. Rack applications can be hosted at a place like Heroku.

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