Clhorus experimentation project

This project aims to experiment DDD concepts using Clojure.

What are implemented?

• Contexts:

  • Operational (the main context).
  • Analytics.

• Rest API:

  • Register a new user.

• Command bus.

• Domain event publisher.

• Repositories:

  • Save a user.
  • Save a user registration.

• Component.

  • The use of this library provides a fast workflow as is described in this post.

• RabbitMQ workers.

• Tests:

  • User registrator service.

Installation

• Create a MySQL database called clhorus_operational_tests.
• Dump this SQL:

CREATE TABLE `user` (
  `id` binary(16) NOT NULL,
  PRIMARY KEY (`id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

• Create a MySQL database called clhorus_analytics_tests.
• Dump this SQL:

CREATE TABLE `user_registration` (
  `user_id` binary(16) NOT NULL,
  `registration_date` TIMESTAMP NOT NULL DEFAULT CURRENT_TIMESTAMP,
  PRIMARY KEY (`user_id`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8;

• Create a MySQL database called clhorus_analytics_tests.
• Dump this SQL:

CREATE TABLE `domain_event_2` (
  `id` bigint(20) NOT NULL AUTO_INCREMENT,
  `aggregate_id` varchar(255) NOT NULL,
  `name` varchar(255) NOT NULL,
  `data` varchar(21000) NOT NULL,
  `occurred_on` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP ON UPDATE CURRENT_TIMESTAMP,
  PRIMARY KEY (`id`),
  KEY `in_aggregate_id` (`aggregate_id`),
  KEY `in_name` (`name`),
  KEY `in_occurred_on` (`occurred_on`)
) ENGINE=InnoDB DEFAULT CHARSET=utf8

• Configure database connection in:

  • clhorus/context/operational/infrastructure/config.clj
  • clhorus/context/analytics/infrastructure/config.clj

• Install and run RabbitMQ.

• Run:

lein run -m clhorus.core

• Try:

curl http://localhost:8080
curl --data "id=4d09a800-3838-11e4-916c-0800200c9a66" http://localhost:8080/users -v

Test

lein midje

Workflow without reload the JVM

The idea behind is to start a REPL just once and write code and test it without reload the JVM. I used component library to achieve that. For further knowledge read this post.

Try it

• Start the REPL:

lein repl

• On your REPL:

(go)

• On other terminal:

curl http://localhost:8080/foo

• You get Not found

• Now you can change the code to create a new endpoint on the API:

clhorus/app/api/routing/users.clj:

(defn routes-users [operational-command-bus]
  (routes
    (GET "/foo" [] "Foo...")
    (GET "/users" [] "Not implemented yet :P")
    (POST "/users" request (users-post operational-command-bus request))))

• On your REPL:

(reset)

• On the terminal:

curl http://localhost:8080/foo

• Now you have a new endpoint working.

Compile, run and connect to the REPL

lein uberjar
java -jar target/clhorus-0.0.1-SNAPSHOT-standalone.jar
lein repl :connect localhost:7888

TODO

• Try Datomic.

Enjoy! :)