Dapr Microservices with Docker Compose

This project demonstrates a microservices architecture using Dapr, Spring Boot, and Docker Compose. It consists of two services, service-a and service-b, each running with its own Dapr sidecar. The services communicate with each other using Dapr's service invocation API, and service-b logs messages to a MySQL database.

Architecture Overview

• Service A: Sends a ping request to service-b using Dapr's service invocation.
• Service B: Receives the ping request, processes it, and logs the message to a MySQL database.
• Dapr Sidecars: Each service has a Dapr sidecar (service-a-dapr and service-b-dapr) to handle service discovery and communication.
• MySQL Database: Used by service-b to store request details.

Prerequisites

• Docker Desktop installed
• curl installed for testing endpoints
• MySQL client (optional, for database inspection)

Configuration

Environment Variables

The .env file contains the following configurations:

# .env.example
MYSQL_ROOT_PASSWORD=<your_mysql_root_password>
MYSQL_DATABASE=<your_database_name>
MYSQL_USER=<your_database_user>
MYSQL_PASSWORD=<your_database_password>
SPRING_DATASOURCE_URL=jdbc:mysql://<your_mysql_host>:3306/<your_database_name>
SPRING_DATASOURCE_USERNAME=<your_database_user>
SPRING_DATASOURCE_PASSWORD=<your_database_password>
DAPR_CLIENT_ENABLED=false

Docker Compose Network

All containers are connected to the dapr-network defined in the docker-compose.yaml file.

Getting Started

Follow these steps to build, run, and test the application:

Step 1: Stop and Remove Existing Containers

docker-compose down -v

Step 2: Build and Start All Containers

docker-compose up --build

Step 3: Verify Network Connectivity

Ensure all containers are in the same network:

docker network inspect msuk-dapr_dapr-network

Step 4: Health Checks for Services

Check the health of both services:

curl http://localhost:5001/actuator/health
curl http://localhost:5002/actuator/health

Step 5: Test Service-B Dapr Sidecar

Invoke service-b through its Dapr sidecar:

curl -X POST http://localhost:3501/v1.0/invoke/service-b/method/service-b/ping \
-H "Content-Type: application/json" \
-d '{"message": "test ping from terminal"}'

Step 6: Test Service-A to Service-B Communication

From service-a, invoke service-b through its Dapr sidecar:

docker exec -it service-a curl -X POST http://service-b-dapr:3501/v1.0/invoke/service-b/method/service-b/ping -H "Content-Type: application/json" -d '{"message": "ping from Service A container"}'

Step 7: Verify Database Entries

Check if the messages are logged in the MySQL database:

docker exec -it mysql mysql -u dapr -p

USE dapr_poc;
SELECT * FROM request_details;

Step 8: Test Service-A Dapr Sidecar

Invoke service-a through its Dapr sidecar:

curl -X GET http://localhost:3500/v1.0/invoke/service-a/method/service-a/ping

Additional Notes

• Dapr Ports:
  • 3500: Dapr HTTP API for service-a
  • 3501: Dapr HTTP API for service-b
• MySQL:
  • Database: Refer to the .env file for the database name.
  • User: Refer to the .env file for the database username.
  • Password: Refer to the .env file for the database password.

Cleanup

To stop and remove all containers, networks, and volumes:

docker-compose down -v