microservices-sample

Ratpack based microservices sample with two service:

• User Service: A simple service for adding and connecting users.
• Persistence Service: For saving entities and finding them by id.

User Service uses Persistence Service for persisting users. Persistence Service will be discovered automatically, there is no need to pass details to User Service runner.

Current Persistence Service implementation uses Hazelcast as in-memory, distributed database.

Building

Build user-service:

cd user-service
../gradlew shadowJar

Build persistence-service:

cd user-service
../gradlew shadowJar

Note: shadowJar task will create a single fat jar file in build/libs directory.

Quick test

After building the services, run user-service and persistence-service in two separate terminals:

User-service:

cd user-service/build/libs/
java -jar user-service-0.0.1-all.jar

Persistence-service:

cd persistence-service/build/libs/
java -jar persistence-service-0.0.1-all.jar

Note:

• persistence-service must be run after user-service to be discovered automatically.

Create first user:

curl -X POST -H "Content-Type: application/json" -d '{"name": "user1"}' http://localhost:2000/v1/users
# or with httpie
echo '{"name": "user1"}' | http post :2000/v1/users

Create second user:

curl -X POST -H "Content-Type: application/json" -d '{"name": "user2"}' http://localhost:2000/v1/users
#or
echo '{"name": "user2"}' | http post :2000/v1/users

Connect user1 to user2:

curl -X POST http://localhost:2000/v1/users/<user1-id>/connect?to=<user2-id>
#or
http post :2000/v1/users/<user1-id>/connect?to<user2-id>

Get users connections:

curl http://localhost:2000/v1/users/<user1-id>/connections
#or
http :2000/v1/users/<user1-id>/connections

See UserServiceTest integration test for service usage.

Issues

Hazelcast nodes can not detect each other on two different hosts.

Modules

• user-service: User service implementation
• persistence-service: Persistence service implementation
• service-discovery: Service discovery definitions
• hazelcast-discovery: Hazelcast-based service discovery implementation
• base-server: Helpers and base classes for building Ratpack-based micro-service
• service-api: Base classes and REST definitions for clients

Running tests

Unit tests:

./gradlew test

Integration tests:

./gradlew intT