spring-cloud-stream-solace-pubsub

The goal of this project is to play with Solace PubSub+. For it, we will implement a producer and consumer of different types of news about many countries and cities.

Proof-of-Concepts & Articles

On ivangfr.github.io, I have compiled my Proof-of-Concepts (PoCs) and articles. You can easily search for the technology you are interested in by using the filter. Who knows, perhaps I have already implemented a PoC or written an article about what you are looking for.

Additional Readings

• [Medium] Solace PubSub+ and Spring Boot: Implementing News Producer and Consumer Apps
• [Medium] Solace PubSub+ and Spring Boot: Implementing Unit Tests for News Producer and Consumer Apps
• [Medium] Solace PubSub+ and Spring Boot: Implementing End-to-End Tests for News Producer and Consumer Apps
• [Medium] Solace PubSub+ and Spring Boot: Running News Producer and Consumer Apps in Minikube (Kubernetes)

Applications

• producer-service

  Spring Boot application that exposes a REST API to submit news events. It published news to the following destination with format: ps/news/{type}/{country}/{city}

  Endpoints

  POST /api/news {"type": [SPORT|ECONOMY|HEALTH], "country": "...", "city": "...", "title": "..."}
  POST /api/news/random {"number": ..., "delay": ...}
  

• consumer-service

  Spring Boot application that consumes the news events published by producer-service.

Prerequisites

• Java 21 or higher.
• A containerization tool (e.g., Docker, Podman, etc.)

Start Environment

Open a terminal and inside the spring-cloud-stream-solace-pubsub root folder run:

docker compose up -d

Running Applications with Maven

• producer-service

  • In a terminal, make sure you are in the spring-cloud-stream-solace-pubsub root folder.
  • Run the commands below:

    ./mvnw clean spring-boot:run --projects producer-service

• consumer-service-1

  • It subscribes to all news from Brazil.
  • Open a new terminal and navigate to the spring-cloud-stream-solace-pubsub root folder.
  • Run the commands below:

    export NEWS_SUBSCRIPTION="ps/news/*/BR/>"
    ./mvnw clean spring-boot:run --projects consumer-service

• consumer-service-2

  • It subscribes to all news related to HEALTH.
  • Open a new terminal and navigate to the spring-cloud-stream-solace-pubsub root folder.
  • Run the commands below:

    export SERVER_PORT=9082
    export NEWS_SUBSCRIPTION="ps/news/HEALTH/>"
    ./mvnw spring-boot:run --projects consumer-service

Running Applications as Docker containers

• Build Docker Images

  • In a terminal, make sure you are inside the spring-cloud-stream-solace-pubsub root folder.
  • Run the following script to build the Docker images:

    ./build-docker-images.sh

• Environment Variables

  • producer-service

    Environment Variable	Description
    SOLACE_HOST	Specify host of the Solace PubSub+ message broker to use (default localhost)
    SOLACE_PORT	Specify port of the Solace PubSub+ message broker to use (default 55556)

  • consumer-service

    Environment Variable	Description
    SOLACE_HOST	Specify host of the Solace PubSub+ message broker to use (default localhost)
    SOLACE_PORT	Specify port of the Solace PubSub+ message broker to use (default 55556)

• Run Docker Containers

  • producer-service

    Run the following command in a terminal:

    docker run --rm --name producer-service \
      -p 9080:9080 \
      -e SOLACE_HOST=solace -e SOLACE_PORT=55555 \
      --network=spring-cloud-stream-solace-pubsub_default \
      ivanfranchin/producer-service:1.0.0

  • consumer-service-1

    • It subscribes to all news from Brazil.
    • Open a new terminal and run the following command:

      docker run --rm --name consumer-service-1 \
        -p 9081:9081 \
        -e SOLACE_HOST=solace -e SOLACE_PORT=55555 \
        -e NEWS_SUBSCRIPTION="ps/news/*/BR/>" \
        --network=spring-cloud-stream-solace-pubsub_default \
        ivanfranchin/consumer-service:1.0.0

  • consumer-service-2

    • It subscribes to all news related to HEALTH.
    • Open a new terminal and run the following command:

      docker run --rm --name consumer-service-2 \
        -p 9082:9081 \
        -e SOLACE_HOST=solace -e SOLACE_PORT=55555 \
        -e NEWS_SUBSCRIPTION="ps/news/HEALTH/>" \
        --network=spring-cloud-stream-solace-pubsub_default \
        ivanfranchin/consumer-service:1.0.0

Playing around

In a terminal, submit the following POST requests to producer-service and check its logs and consumer-service logs.

Note: HTTPie is being used in the calls bellow

• Sending news one by one

  • Just consumer-service-1 should consume:

    http :9080/api/news type="SPORT" country="BR" city="SaoPaulo" title="..."
    

  • Just consumer-service-2 should consume:

    http :9080/api/news type="HEALTH" country="PT" city="Porto" title="..."
    

  • Neither consumer-service-1 nor consumer-service-2 should consume:

    http :9080/api/news type="ECONOMY" country="DE" city="Berlin" title="..."
    

  • Both consumer-service-1 and consumer-service-2 should consume:

    http :9080/api/news type="HEALTH" country="BR" city="Brasilia" title="..."
    

• Sending a number of news randomly with a specified delay in milliseconds:

  http :9080/api/news/random number=10 delayInMillis=1000 --stream
  

Useful Links

• Solace

  Solace can be accessed at http://localhost:8080 and enter admin to both username and password.

Shutdown

• To stop applications, go to the terminals where they are running and press Ctrl+C.
• To stop and remove docker-compose containers, network and volumes, go to a terminal and, inside the spring-cloud-stream-solace-pubsub root folder, run the following command:

  docker compose down -v
  

Running Test Cases

In a terminal, make sure you are inside the spring-cloud-stream-solace-pubsub root folder:

• producer-service

  ./mvnw clean test --projects producer-service
  

• consumer-service

  ./mvnw clean test --projects consumer-service
  

Cleanup

To remove the Docker images created by this project, go to a terminal and, inside the spring-cloud-stream-solace-pubsub root folder, run the following script:

./remove-docker-images.sh

References

• https://tutorials.solace.dev/spring/spring-cloud-stream/

Issues

The default Solace SMF port 55555 is not working, at least on my Mac machine. The problem is explained in this issue. For now, I've changed the mapping port from 55555 to 55556.