ePizza - A Microservices Hands-On Tutorial
- experience core principles of Microservices architecture
- isolated runtimes
- Java & Spring Boot technology stack
- persistence with JPA
- exposes synchronous REST/JSON endpoints
- consumes external synchronous REST/JSON endpoints
- sends asynchronous events over message bus
- receives asynchronous events over message bus
This project contains a collection of four microservices based on spring-boot, communicating via REST and AMQP. The "start-group-delivery" and "start-group-bakery" branches contain the starting points for implementing two services. The "ref" branch contains the reference implementations. Avoid peeking here without trying yourself first. :-)
The folder pizza-service-intro/index.html contains a presentation that gives an overview of the application.
The exercise branches "start-group-delivery" and "start-group-bakery" contain a presentation explaining the tasks (delivery/exercise-instructions/index.html or bakery/exercise-instructions/).
We dockerized our microservices and you can use docker-compose to run the solution.
You need to install docker and docker-compose. If you are not on linux you also need docker-machine.
Start the event bus:
infrastructure/start.sh
Start the microservices:
./service.sh
In order to point the ui to the correct backend you might need to change the following lines to point to your docker host ip in the docker-compose.yml
- CATALOG_API_BACKEND_HOST=http://192.168.99.100:8081
- ORDER_API_BACKEND_HOST=http://192.168.99.100:8082
On linux your docker host ip should be localhost. if you run docker machine you can find the ip by running:
docker-machine env <name-of-docker-vm>
You should be able to reach the UI under
http://<docker-ip>:8085
All the service have an index endpoint that tells you which resources they expose
e.g. the order service:
curl -X GET 'http://192.168.99.100:8082'
The result is this - it just manages an orders resource:
{
"_links": {
"self": {
"href": "http://192.168.99.100:8082/",
"templated": false
},
"orders": {
"href": "http://192.168.99.100:8082/orders",
"templated": false
}
}
}Catalog service:
curl -X GET 'http://192.168.99.100:8081'
Bakery service:
curl -X GET 'http://192.168.99.100:8083'
Delivery service:
curl -X GET 'http://192.168.99.100:8081'
curl -X POST -H "Content-Type: application/json" -d '{
"orderItems": [{
"pizza": "http://192.168.99.100:8081/pizzas/1",
"amount": 2
},
{
"pizza": "http://192.168.99.100:8081/pizzas/2",
"amount": 1
}
],
"deliveryAddress": {
"firstname": "Mathias",
"lastname": "Dpunkt",
"street": "Some street 99",
"city": "Hamburg",
"postalCode": "22222",
"telephone": "+4940111111"
},
"comment": "Slice it!"
}' 'http://192.168.99.100:8082/orders'
The location header of the response contains the URI of the order.
curl -X GET 'http://192.168.99.100:8082/orders/1'
This will give you something like this - you should see the status change until it reaches DELIVERED.
{
"status": "DELIVERED",
"created": "2015-09-25T08:09:53.409",
"estimatedTimeOfDelivery": "2015-09-25T08:10:28.933",
"totalPrice": "EUR 27.70",
"orderItems": [
{
"pizza": "http://192.168.99.100:8081/pizzas/1",
"amount": 2,
"price": "EUR 8.90"
},
{
"pizza": "http://192.168.99.100:8081/pizzas/2",
"amount": 1,
"price": "EUR 9.90"
}
],
"deliveryAddress": {
"firstname": "Mathias",
"lastname": "Dpunkt",
"street": "Some street 99",
"city": "Hamburg",
"postalCode": "22222",
"telephone": "+4940111111"
},
"_links": {
"self": {
"href": "http://192.168.99.100:8082/orders/1",
"templated": false
}
}
}You can also query the bakery and deliver service for their status of the order.
curl -X GET 'http://192.168.99.100:8083/bakery-orders'
curl -X GET 'http://192.168.99.100:8084/delivery-orders'
{
"_links": {
"self": {
"href": "http://192.168.99.100:8084/delivery-orders",
"templated": false
}
},
"_embedded": {
"deliveryOrders": [
{
"orderLink": "http://192.168.99.100:8082/orders/1",
"deliveryOrderState": "DONE"
}
]
},
"page": {
"size": 20,
"totalElements": 1,
"totalPages": 1,
"number": 0
}
}If you are interested in the topic and want to go further you can have a look at the following good reads:
- Sam Newman's "Building Microservices" is an excellent read on microservices and the challenges and benefits associated with it
- Martin Fowler's "Microservices Resource Guide"
- "Richardson Maturity Model - steps toward the glory of REST" by Martin Fowler
- Patterns of Enterprise Application Architecture