Sample microservice Ruby application built using Grape, Grape Swagger, and Grape Entity deployed to IBM Bluemix (Cloud Foundry)
Using the Grape DLS to implement your service API, along with Grape-Swagger allows you to easily produce documentation that conforms to the Swagger 1.2 Specification. Unfortunately Grape-Swagger does not yet support the Swagger 2.0 specification.
Here is an example of the GET operation for getting a collection of Sales records.
class SalesApi < Grape::API
version 'v1', using: :path
format :json
default_format :json
namespace :sales do
desc 'List of sales', entity: Entities::Sales
get '/', http_codes: [[200, 'Ok', Entities::Sales]] do
present SalesAccess.fetch_all, is_array: false, with: Entities::Sales, type: :full
end
...........
end
Once a service is bound to your application(See the Deploy to Bluemix section) you can access it using the properties in the VCAP_SERVICES environment variable. This variable is added to the environment by Cloud Foundry.
The sample application shows how you can read the Redis information from the VCAP_SERVICES variable when running on Cloud Foundry, as well as using the default connection when running locally. See the "Getting started with Redis service" for more information.
class RedisConnection
def self.client
Redis.new(host: credentials['hostname'], port: credentials['port'], password: credentials['password'])
end
private
def self.credentials
@credentials ||= fetch_credentials
end
def self.fetch_credentials
credentials = {'credentials'=>{'port'=>'6379', 'hostname'=>'localhost', 'password'=>''}}
if ENV['VCAP_SERVICES']
services = JSON.parse(ENV['VCAP_SERVICES'])
redis_service = services['redis-2.6']
credentials = redis_service.first['credentials'] if redis_service
end
credentials
rescue Exception => e
$stderr.puts 'Error in config'
$stderr.puts "Error: #{e.message}"
end
end
Clone or fork this repository then run bundle to install the dependent gems.
git clone https://github.com/tbeauvais/bluemix-microservice-sample.git
cd bluemix-microservice-sample
bundle
For simplicity the sample uses Redis as its datastore. The easiest way to install Redis on a Mac is to use homebrew
$ brew install redis
Start Redis
$ redis
Once Redis has started you can start the sample application using the puma server.
$ bundle exec puma
Once the application has started you can open http://petstore.swagger.io/ in your browser, and point the Swagger UI to your local running server.
http://localhost:9292/swagger_doc
From here you can start by adding some sample data using the POST operation. Once you have some sales records you can view them using the GET operation.
If you don't already have an account on IBM Bluemix you will need to create one in order to deploy the sample application. You should also be familiar with Cloud Foundry and have the Cloud Foundry command line tool installed.
First you will need to edit the "name" and "host" in the manifest.yml file to ensure the application name and route to the application are unique. For example:
applications:
- name: my-sales-microservice-sample
host: my-sales-microservice-sample
$ cf api https://api.ng.bluemix.net
$ cf login
Run the cf create-service command to create a Redis service instance. The name you give the instance (redis-db1) must match the service name specified in the manifest.yml file since that's what the application will be bound to.
$ cf create-service redis 100 redis-db1
Run the following commands from the cloned repository (e.i. bluemix-microservice-sample). This will connect you to Bluemix and then push the application to the the Cloud Foundry server, as well as bind the application to the service instance.
$ cf push
Once the application has started you can open http://petstore.swagger.io/ in your browser, and point the Swagger UI to the application running on Bluemix.
http://my-sales-microservice-sample.mybluemix.net/swagger_doc
