In this blog post we use an example application to demonstrate how to instrument a microservices application using the Elastic APM, with focus on Distributed Tracing.
- Frontend part is a Javascript application, provides UI. Created with VueJS
- Auth API is written in Go and provides authorization functionality
- TODOs API is written with NodeJS, provides CRUD functionality ove user's todo records. Also, it logs "create" and "delete" operations to Redis queue, so they can be later processed by Log Message Processor.
- Users API is a Spring Boot project written in Java. Provides user profiles.
- Log Message Processor is a very short queue processor written in Python. It's sole purpose is to read messages from Redis queue and print them to stdout
Take a look at the components diagram that describes them and their interactions.
The original project instrumeted the example app using Zipkin. This fork used the Elastic APM
The demo uses the elastic stack on APM on ESS. If you don’t have an Elasticsearch Service account already, you can set up a trial one. It comes with an APM server included as default.
To get the example application running locally on our local machine and configure to send APM data to the Elasticsearch Service cluster. We need to clone the project i.e.
git clone https://github.com/nephel/microservice-app-example.git
cd microservice-app-example
Create a file called .env at the root directory of the project with the contents: vi .env`
Adding the token and server URL values for the APM sever, that correspond to our environment.
TOKEN=XXXX
SERVER=XXXX
Use docker-compose:
docker-compose up --build
Then go to http://127.0.0.1:8080 for web UI.
Usernames/passwords are defined in microservice-app-example/auth-api/user.go as follows:
- admin/admin
- johnd/foo
- janed/ddd
This is definitely a contrived project, so it can be extended in any way you want.
MIT