priitserk / spring-boot-kafka-redis-docker

Experimental spring boot 2 - Apache kafka - REDIS and Docker implementation

Experimental PoC playing around with Spring Boot 2 microservices, Apache Kafka as a Queue and REDIS as a cache all built and run with Docker. Inclues OpenAPI spec APIs and Swagger-UI for testing + Embedded Kafka in IT tests.

PROJECT KEY POINTS

NB: project dependencies must be first built before running docker-compose up --build. Please execute mvn clean package in prior to that (Step by step example in the PROJECT STARTUP WITH DOCKER-COMPOSE section )

• Apache Maven project (always import project by pom.xml)
• JDK 11
• Dependencies: Apache Kafka; Zookeeper; REDIS Spring Boot & Swagger
• APISs by OpenAPI 3.0 standard
• all configuration externalized, both logback and application.properties for microservices.
• Developed and tested on Windows using
  -- OpenJDK Runtime Environment AdoptOpenJDK (build 11.0.3+7)
  -- Apache Maven 3.6.2
  -- docker-compose version 1.25.4, build 8d51620a

PROJECT STRUCTURE

├── [config]
├── [common]
├── [consumer]
├── [daemon]
├── pom.xml
└── docker-compose.yml

• [config] "prod" configuration files that are copied to the unix images on startup. No configuration is assembled to jar files.
• [common] - common code used by both modules consumer and daemon. Imported to dependent modules through pom.xml
• [consumer] - serves as microservice 1 - produces Swagger UI, APIs and implements Kafka producer logic
• [daemon] - serves as microservice 2- listens and processes messages from Kafka; REDIS integration

TESTS

Demonstrational tests have been created under [daemon] module. Both simple unit test for Monitoring Service and SocialRatingCalculator and additionally to Kafka listener. Tests are automatically executed on mvn clean package command.

IMPORTANT ENDPOINTS

• [daemon] up and running: http://localhost:9002/daemon-service/
  If service is up and running the following response should be there:
  {"status":"UP","version":"1.0","name":"daemon-service","buildTime":"2020-04-20T17:18:41+0000","currentTime":"2020-04-22T03:23:23+0000"}

• [consumer] up and running: http://localhost:9001/consumer-service/
  If service is up and running the following response should be there:
  {"status":"UP","version":"1.0","name":"consumer-service","buildTime":"2020-04-20T17:18:41+0000","currentTime":"2020-04-22T03:23:23+0000"}

• [SWAGGER UI] http://localhost:9001/consumer-service/swagger-ui.html
  User interface for testing provided APIs.

PROJECT STARTUP WITH DOCKER-COMPOSE

1. navigate to project root (same directory where docker-compose.yml and pom.xml is located)
2. verify versions and availability of docker and maven
   $ docker-compose -version
   Output: docker-compose version 1.25.4, build 8d51620a
   $ mvn -version
   Apache Maven 3.6.2 (40f52333136460af0dc0d7232c0dc0bcf0d9e117; 2019-08-27T18:06:16+03:00)
   Maven home: C:\apache-maven-3.6.2\bin..
   Java version: 11.0.3, vendor: AdoptOpenJDK, runtime: C:\Program Files\AdoptOpenJDK\jdk-11.0.3.7-hotspot
3. Build dependencies (build the project and related dependencies)
   $ mvn clean package
   results in 2 jars with dependencies under target directories of consumer and daemon module and tests are executed under daemon module
4. Start services
   $ docker-compose up --build
5. Verify service are running
   After the components are built and deployed, verify that monitoring endpoints respond:
   * http://localhost:9002/daemon-service/
   * http://localhost:9001/consumer-service/
6. Open up Swagger-UI
   • http://localhost:9001/consumer-service/swagger-ui.html
7. Try out /v1/person-data/collect service.
   • Consider business logic constraint on Age (@Range(min = 18, max = 70))
   • example curl: curl -X POST "http://localhost:9001/consumer-service/v1/person-data/collect" -H "accept: application/json" -H "Content-Type: application/json" -d "{ "age": 66, "firstName": "string", "lastName": "string"}"

If proper age range is used, results are printed to docker console. Information about REDIS cache entry is logged aswell to console with every response.