Spring Tracing Example

This is a simple example of how to use Spring Cloud Sleuth to trace a request through a Spring Boot applications in microservices architecture.

How it works

There are 3 services:

• web-facade - a web application that receives requests and calls other services
• rest-service - a REST service that returns a name
• queue-service - a service that receives messages from a queue and audit (logs) them

How to run

Build Docker images:

mvn clean spring-boot:build-image 

This command will build Docker images for all services:

• docker.io/library/web-facade:0.0.1-SNAPSHOT
• docker.io/library/rest-service:0.0.1-SNAPSHOT
• docker.io/library/queue-service:0.0.1-SNAPSHOT

Once images are built, you can run them using docker-compose:

cd docker
docker compose up

How to test

To test the application, you can use curl:

curl http://localhost:8080/?name=Batman

Result would be something like:

Batman, Hello from Galadriel

And in logs you can see something like:

web-facade     | 2023-11-23 01:18:03.073  INFO [web-facade,fb502d77543e7f75,fb502d77543e7f75] 1 --- [nio-8080-exec-5] c.v.t.mdclogtraining.HelloController     : GET hello. name='Batman'
web-facade     | 2023-11-23 01:18:03.084  INFO [web-facade,fb502d77543e7f75,fb502d77543e7f75] 1 --- [nio-8080-exec-5] c.v.training.mdclogtraining.NameClient   : Calling name service at 'http://rest-service:8081/api/name'
rest-service   | 2023-11-23 01:18:03.113  INFO [rest-service,fb502d77543e7f75,07f850786f2f9c3a] 1 --- [nio-8081-exec-4] c.v.training.restservice.NameService     : New name='Galadriel'
queue-service  | 2023-11-23 01:18:03.131  INFO [queue-service,fb502d77543e7f75,8dcd4c5f573fdc3b] 1 --- [ntContainer#0-1] c.v.training.queueservice.AuditService   : Audit message: Hello from Galadriel

Pay attention on trace id fb502d77543e7f75 - it is the same for all involved services.