README

A simple rails service to demonstrate consuming and publishing from a message queue.

Stack Overview

Ruby 2.4
Rails 5.1.4
Docker & Docker Compose
RabbitMq

Set up

Follow the instructions to install Docker and Docker Compose.
Once docker is installed, run

docker-compose up --build

When you build and start the container, it will automatically start your Sneakers service.
To stop the application, go to your terminal where you are running the docker containers and press CTRL+C.
To stop the services, run docker-compose stop.
To stop the containers, run docker-compose down.

Local development

Once you have created your images, you can use docker-compose up to start the containers. Please refer to docker-compose help for all commands.

Developing a Rails application on a docker container is not so different from development in a local environment. You should be able to run all commands as you normally would, but you must prefix them with docker-compose exec ${name of container}. The containers are named as so:

gateway - runs Sneakers

For example, running bundle install on the Rails service looks like:

docker-compose exec gateway bundle install

See the docker-compose.yml in the root of the project for configuration.

Consuming and Publishing Messages

This service publishes messages to an AMQP server using RabbitMq. You can start this server following the directions in the message-queue repository.

This service uses Sneakers to listening to the queues and run background jobs. Starting the docker container will also start sneakers. To start it manually, you can use docker-compose exec gateway rake sneakers:run

Testing

Unit tests

docker-compose exec gateway rspec

Mountebank

Mountebank allows you to stub out responses from external dependencies. This service depends on an external service to provide the account key.

To use Mountebank, you'll need to install it:

npm install -g mountebank

To run Mountebank with the configured stubs:

 mb --configfile config/mountebank/imposters.ejs --allowInjection --logfile tmp/mb.log

Once Mountebank is running, you can go to localhost:2525 to view the Mountebank help documentation. Our stubbed service lives at localhost:9001/v1/account. To point the application to the stub, change the ACCOUNT_KEY_SERVICE environment variable.

# In the .env file, point this environment variable to your stub 

#Instead of this:
ACCOUNT_KEY_SERVICE=https://account-key-service.herokuapp.com

#Use this: 
ACCOUNT_KEY_SERVICE=http://localhost:9001

This is not an ideal set up, further work should be done to automate this.

There are a few simple stubs in available:

POST /v1/account with body:

{
  "email": "user1@email.com",
  "key": "1_key"
}

{
  "email": "user2@email.com",
  "account_key": "2_account_key"
}

will return account keys. Any other request to localhost:9001 will return back a 200 and an error message, like the real account service.

tchen10 / sub-pub-gateway