Step by Step Guide to Building an Azure DevOps API Integration in Ruby

Introduction

Hey there, fellow developer! Ready to dive into the world of Azure DevOps API integration using Ruby? You're in for a treat! We'll be using the nifty omniauth-azure-devops package to make our lives easier. Buckle up, and let's get coding!

Prerequisites

Before we jump in, make sure you've got:

• A Ruby environment set up and ready to roll
• An Azure DevOps account with a project to play with

Got those? Great! Let's move on.

Setting up the project

First things first, let's create a new Ruby project:

mkdir azure_devops_integration
cd azure_devops_integration
bundle init

Now, open up that Gemfile and add these gems:

gem 'sinatra'
gem 'omniauth-azure-devops'
gem 'httparty'

Run bundle install, and we're off to the races!

Configuring omniauth-azure-devops

Time to set up our OmniAuth middleware. Create a new file called app.rb and add this:

require 'sinatra'
require 'omniauth-azure-devops'

use OmniAuth::Builder do
  provider :azure_devops, ENV['AZURE_CLIENT_ID'], ENV['AZURE_CLIENT_SECRET']
end

Don't forget to set those environment variables with your Azure DevOps app credentials!

Authenticating with Azure DevOps

Let's add some routes to handle authentication:

get '/auth/azure_devops' do
  # This route will trigger the authentication process
end

get '/auth/azure_devops/callback' do
  auth = request.env['omniauth.auth']
  session[:token] = auth['credentials']['token']
  "Authentication successful!"
end

Making API requests

Now for the fun part - let's fetch some work items:

get '/work_items' do
  response = HTTParty.get(
    'https://dev.azure.com/{organization}/{project}/_apis/wit/workitems?api-version=6.0',
    headers: {
      'Authorization' => "Bearer #{session[:token]}",
      'Content-Type' => 'application/json'
    }
  )
  response.body
end

Handling pagination and rate limiting

Azure DevOps API uses pagination for large datasets. Here's a quick way to handle it:

def fetch_all_work_items
  items = []
  continuation_token = nil

  loop do
    response = fetch_work_items(continuation_token)
    items += response['value']
    continuation_token = response['continuationToken']
    break if continuation_token.nil?
    sleep 1 # Respect rate limits
  end

  items
end

Error handling and logging

Always be prepared for things to go wrong:

def make_api_request(url)
  response = HTTParty.get(url, headers: { 'Authorization' => "Bearer #{session[:token]}" })
  
  case response.code
  when 200
    response.body
  when 401
    logger.error "Unauthorized: Token may have expired"
    nil
  else
    logger.error "API request failed: #{response.code} - #{response.message}"
    nil
  end
rescue StandardError => e
  logger.error "Error making API request: #{e.message}"
  nil
end

Testing the integration

Don't forget to test! Here's a simple RSpec example:

RSpec.describe "Azure DevOps Integration" do
  it "authenticates successfully" do
    get '/auth/azure_devops/callback'
    expect(last_response).to be_ok
    expect(session[:token]).not_to be_nil
  end
end

Best practices and optimization

Remember to cache API responses when possible and use API resources efficiently. Your future self (and your API quota) will thank you!

Conclusion

And there you have it! You've just built a Ruby integration with the Azure DevOps API. Pretty cool, right? Remember, this is just the beginning. There's so much more you can do with this API, so keep exploring and building awesome things!

Happy coding, and may your builds always be green! 🚀