Putting the API under its own domain - ruby-on-rails

I think there is a wide consent that is a good practice to separate your REST API from your main website. The main reason is that you can scale your API and website independently of each other.
Additionally, Rails has a lot of middleware that is not required for stateless services (e.g. sessions, cookies, view rendering, etc...). Jeff Dean has a good write up on how to remove all of this middleware (http://pivotallabs.com/users/jdean/blog/articles/1419-building-a-fast-lightweight-rest-service-with-rails-3-).
At the moment, I am simply using the new Rails 3 responder (respond_with) in one single application, both for the website and the API. The website is used mainly for administration purposes.
How would you separate the API from the website?
I think an option would be to pack all models in a gem, then have two different applications, one lightweight REST service, and the administration website. They would be hosted on different Heroku instances, but access the same MongoHQ database.

You have 2 choice
extract your Model ans use it in all of your 2 application
made you API and your application on same application. But you deploy 2 server. One using only your application par and other with your API part. So if you need more API. add more on your API server.
You don't really need extract API. You just need separate it.

Related

Existing Ruby on Rails web app on Heroku (PostgreSQL), Devise authentication, need to add Rails API for mobile backed

I have an existing RoR web application which currently uses Devise for authentication.
I am planning on adding API functionality in one manner or another for a mobile backend.
Would you recommend adding API functionality to the web application and using JWT, for example, to enable mobile authentication. Alternatively, would you have two separate applications, a web application and an API, sharing the same Postgres instance on Heroku?
I see pros and cons both ways, but it would seem to me that separating it into two applications would outweigh adding API functionality to the web app. Perhaps, it would make most sense to start over with just an API and add mobile app client and web application client functionality.
Creating a new API only backend might be easier at first, but you would have to copy all your app logic in the models over and keeping both sides up to date will be a pain. You can do it in the same rails app if you namespace the new API so that all calls are under a /api_v1 or something like that. Here is an article that show how you can have different versions of your API.
JWTs for authentication is a great way of doing it and Devise can support them by adding a gem like devise-jwt since adding a route and handling the creation and updating of tokens by yourself is a lot of work.
For the API itself you might want to consider using JSON:API with the jsonapi-rails gem or GraphQL with the graphql gem. This way when someone wants to use your API they can use an adapter for their framework that can talk to that kind of API and not have to worry about the structure of what it returns. There are adapters for both APIs that work with Andrioid, IOS, Ember, React, and all other major frontend frameworks.

How do you create an API server based on data from an existing Rails/Postgres web application?

I have an existing web application that's developed with Ruby on Rails and PostgreSQL. I need to create a mobile application (and possibly a separate web application) using the data from that web application, so I'm looking to create an API server. Is it possible to do this without altering the source code from the original Rails/Postgres web application?
Any ideas on the best way to do this? Or can someone point me in the right direction on what to research?
To connect a new application hosted on Heroku to a PostgreSQL database hosted on Heroku just push your new application to Heroku as normal.
Then, under Settings on your new application dashboard, go into Config Variables and add a new config for DATABASE_URL. Put the value of the url for your existing database.
Your new application will need to be under the same account as your existing application. Heroku doesn't allow you to connect across accounts.
You probably want to take a look at this question for additional details.
Sounds like essentially you want to have two applications connecting to the same database offering the same methods, but respond in different formats (html vs, for example, json). One way of doing that relatively easily might be pushing another api only Rails app to heroku that connects to the same Postgres database (which was mentioned in the comments), but you would have to figure out how to handle authentication differently for your API end points. This depends on whether you are exposing these end points to the public or to something like a mobile front-end. You may want to switch to token-based authentication if you were formerly using sessions on the web-app. Once you implement secure authenticatoin for your api routes, all you have to do is make sure your methods, instead of rendering erb or haml templates, are returning raw data consumable by your intended client.

Communication between Rails apps

I have built two rails apps that need to communicate and send files between each other. For example one rails app would send a request to view a table in the other apps' database. The other app would then render json of that table and send it back. I would also like one app to send a text file stored in its public directory to the other app's public directory.
I have never done anything like this so I don't even know where to begin. Any help would be appreciated. Thanks!
You requirement is common for almost all the web apps irrespective of rails, Communicating with each other is required by most modern web apps. But there is a small understanding that you need to get hold on,
Web sites should not directly access each others internal data (such as tables), (even if they are build by the same language (in this case Rails) by the same developer),
That is where the web-services comes in to play, So you should expose your data through web services so that not only rails application can consume that, but also any app that knows how to consume a web service will get benefit.
Coming back to your question with Rails, rails supports REST web services out of the box, So do some googling about web services, REST web services with rails
HTH
As a starting point, look at ActiveResource.
Railscast
docs
Message queuing systems such as RabbitMQ may be used to communicate things internally between different apps such as a "mailer" app and a main "hub" application.
Alternatively, you can use a shared connection to something like redis stick things onto a "queue" in one app and read them for processing from the other.
In recent Rails versions, it is rather easy to develop API only applications. In the Rails core master, there was even a special application type for these apps briefly (until it got yanked again). But it is still available as a plugin and probably one day becomes actually part of Rails core again. See http://blog.wyeworks.com/2012/4/20/rails-for-api-applications-rails-api-released for more information.
To actually develop and maintain the API of the backend service and make sure both backend and frontend have the same understanding of the resources, you can use ROAR which is great way to build great APIs.
Generally, you should fully define your backend application with an API. Trying to be clever and to skip some of the design steps will only bring you headaches in the long run...
Check out Morpheus. It lets you create RESTful services and use familiar ActiveRecord syntax in the client.

How do I build an API for my Rails app, so that multiple sites can share one database?

I have a Rails application that right now is pretty standard: Heroku/PostgreSQL backend, users go directly to my site to update data, there's no mobile app or anything. We're going to start licensing out the tech to other companies, so that different versions of the interface live on company1.mywebsite.com, company2.mywebsite.com, etc, where all of these interfaces share the same database.
I want some advice on how to go about building this. Do I create a separate Rails app for company1, company2, etc (with a lot of redundant code) and then set up each of them with API keys to query my master app, using its RESTful routes?
Any tutorials to point me to would be great as well.
I recommend you the book Service Oriented Design with Ruby and Rails, by Paul Dix. It has a lot of info about the kind of system that you want to build.
To answer your question:
Build an API server. It serves a JSON – for example – RESTful interface.
api.mydomain/client1/users.json
Build a frontend server. It consume the API service – using typhoeus for example – and serves the final pages. It uses a subdomain or domain name for identification of different clients.
client1.mydomain/users
We have a similar "platform".
What we did:
build a master API app (REST + Push)
build a core plugin for rails which has all the shared code
build a separate rails app for each client which has all the client specific code
We are using this setup for 3 years now and I'm pretty happy with it.

How to provide your app with a network API

I am going to write a Ruby application that implements a video conversion workflow consisting of multiple audio and video encoding/processing steps.
The application interface has two core features:
queueing new videos
monitoring the progress for each video
The user can access these features using a website written in Ruby on Rails.
The challenge is this: I want make the workflow app a self-sufficient application, not dependent on the existence of the web view.
To enable this separation I think that adding a network API to the workflow application is a good solution because this allows the workflow app to reside on a different server than the web server.
My question is: Which solution do you suggest for such a network API?
A few options are:
implement a simple TCP server and invent my own string based API
use some sort of REST api (I don't know if this is appropriate for this situation)
some sort of web-services solution (SOAP, XML-RPC)
another existing framework
Feel free to share your thoughts on this.
I would suggest two things:
First, use REST as your API. This allows you to write one core application with both a user interface and an API for outside applications to use.
Second, take a look at PandaStream. It's a Merb application that encodes videos from multiple formats into flash. It has a REST API, and there's even a Rails plugin so you can integrate it with your application. It might be a good example codebase, or even a replacement for the one you're trying to build.
Hope my answer helped,
Mike

Resources