This project is based upon Spring Boot, Docker and openApi.
The project consists of four microservices:
- restaurant-service,
- food-service,
- configserver,
- eurekaserver,
and a small java library for common classes. In addition, the API is described via openApi and the environment is setup via docker.
The purpose of each microservice is described in the following chapters.
The configserver is a microservice that is based on the Spring Cloud Config project. It provides nearly all configuration parameters for all other microservices. They can be stored in the filesystem or on github or in any other subversion tool or JDBC compatible database. In this project, they are stored in the filesystem.
The mapping from the configuration parameters to the suitable microservice is done via the parameter spring.application.name.
For instance, the configuration for the restaurant-service is stored in a file called restaurant.yaml and the spring.application.name
property in the microservice restaurant-service is restaurant.
Thus, all other microservices depend on the configserver. Therefore, it has to be started first. If we have a different
configuration for a different profile (e.g. docker), the concept is the same as with the application.yaml-naming (e.g
restaurant-docker.yaml).
Service discovery and registration inside this setup is done using Spring Cloud Netflix Eureka. That is, every other microservice
in this collection of microservices has to register itself at the eurekaserver. The eurekaserver also handles load balancing.
All microservices that are supposed to register themselves at the eurekaserver need to have some configuration. This can be
seen in the file restaurant.yaml.
The restaurant-service is a microservice that offers a simple REST-API for CRUD operations. It uses the food-service via a feign client
The API is described via openAPI. Therefore, the API has to be built via an openAPI-command. For this purpose, we use a maven plugin. With following command, the API can be generated
mvn generate-sources
The food-service is a microservice that offers a simple REST-API for CRUD operations.
The API is described via openAPI. Therefore, the API has to be built via an openAPI-command. For this purpose, we use a maven plugin. With following command, the API can be generated
mvn generate-sources
If you want to change the API, do not edit the generated classes but instead edit the restaurant.yaml or food.yaml file, that is
located at the root level of this get repository inside the folder openapi_spec.
Keycloak is set up as identity provider in this scenario. It can be started via docker. During the docker start process a realm is created. This includes the creation of a client in the realm for the gatewayserver and a user (ben, benspassword). So, if http://localhost:8072/dmichel90/restaurants/v1/restaurants is called, the user will be prompted to login. After a successful login, the user will be redirected to the original request. The food-service does not requrire any kind of authorization right now. In theory, the food-service is not supposed to be open to the 'outside world' or it has to be secured, too. (The OpenFeignClient has to be updated in this case.)
All surrounding components like keycloak and the database can be started via docker with the command
docker-compose up
If services should also be started that have a profile, the profile has to be given via
docker-compose up --profile <<PROFILE_NAME>>
for instance docker-compose up --profile sonar, if you want to start sonarqube too.
For development purposes, start the surrounding components (postgresql, keycloak, zipkin and postgresql for keycloak) via docker as described above (without profile).