README.md

docker compose quick start

You can turn an app sim config into a docker compose file using the docker compose generator.

Generate compose file

The generator is available as docker image and you can retrieve it by running

docker pull ghcr.io/cisco-open/app-simulator-generators-docker-compose:latest

To try it out, create the a file called config.yaml with the following content in a new folder:

services:
  frontend:
    type: java
    exposedPort: 3000
    endpoints:
      http:
        /upload:
          - http://processing/magicByte
          - http://processing/virus
  processing:
    type: java
    endpoints:
      http:
        /magicByte:
          - cache,128
        /virus:
          - http://virus-scanner/scan
  virus-scanner:
    type: nodejs
    endpoints:
      http:
        scan:
          - sleep,1500
          - call: error,500,Scan failed
            probability: 0.1
          - sleep,500
loaders:
  user-1:
    type: curl
    wait: 0
    sleep: 2
    urls:
      - http://frontend/upload
      - http://frontend/upload
      - http://frontend/upload

To generate a docker-compose.yaml from this file run

docker run --rm -t -i -v ${PWD}:/mnt ghcr.io/cisco-open/app-simulator-generators-docker-compose --config /mnt/config.yaml --output /mnt/docker-compose.yaml

Run application simulation

To run the simulation using the generated docker-compose.yaml, execute the following in your terminal:

docker compose up

This will bring up the three services (frontend, processing and virus-scanner) and a loader (user-1). Run docker ps to verify that all services are up and running:

CONTAINER ID   IMAGE                                                   COMMAND                  CREATED         STATUS         PORTS                            NAMES
aebccbe1bc54   ghcr.io/cisco-open/app-simulator-services-java:edge     "/entrypoint.sh"         4 seconds ago   Up 3 seconds   8080/tcp, 0.0.0.0:3000->80/tcp   test-app-sim-frontend-1
75218ac52b90   ghcr.io/cisco-open/app-simulator-services-java:edge     "/entrypoint.sh"         4 seconds ago   Up 3 seconds   8080/tcp                         test-app-sim-processing-1
75d7433f85c0   ghcr.io/cisco-open/app-simulator-services-nodejs:edge   "docker-entrypoint.s…"   4 seconds ago   Up 3 seconds   80/tcp                           test-app-sim-virus-scanner-1
5f86a8738e15   ghcr.io/cisco-open/app-simulator-loaders-curl:edge      "/usr/bin/entrypoint…"   4 seconds ago   Up 3 seconds                                    test-app-sim-user-1-1

The loader will continuously load from the /upload endpoint. You can also reach that endpoint yourself, either by opening http://localhost:3000/upload in the browser or by running the following:

curl http://localhost:3000/upload

The docker-compose.yaml that was generated now works independent of the generator. You can use it wherever you want and you can modify it to your needs.

Adding OpenTelemetry and visualize in jaeger

If you want to quickly visualize the simulation, you can add OpenTelemetry using the Java agent and Node.js @opentelemetry/auto-instrumentations-node and send trace data to jaeger.

To do so, download the Java agent and Node.js package:

curl -L -O https://github.com/open-telemetry/opentelemetry-java-instrumentation/releases/latest/download/opentelemetry-javaagent.jar
echo {} > package.json
npm install @opentelemetry/auto-instrumentations-node

Next, create a docker-compose.override.yaml with the following content:

services:
  frontend:
    environment:
      - JAVA_TOOL_OPTIONS=-javaagent:/mnt/opentelemetry-javaagent.jar
      - OTEL_RESOURCE_ATTRIBUTES=service.name=frontend
      - OTEL_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://jaeger:4318
    volumes:
      - ./opentelemetry-javaagent.jar:/mnt/opentelemetry-javaagent.jar
  processing:
    environment:
      - JAVA_TOOL_OPTIONS=-javaagent:/mnt/opentelemetry-javaagent.jar
      - OTEL_RESOURCE_ATTRIBUTES=service.name=processing
      - OTEL_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://jaeger:4318
    volumes:
      - ./opentelemetry-javaagent.jar:/mnt/opentelemetry-javaagent.jar
  virus-scanner:
    environment:
      - NODE_PATH=/mnt/node_modules
      - NODE_OPTIONS=-r "@opentelemetry/auto-instrumentations-node/register"
      - OTEL_RESOURCE_ATTRIBUTES=service.name=virus-scanner
      - OTEL_EXPORTER=otlp
      - OTEL_EXPORTER_OTLP_ENDPOINT=http://jaeger:4318
    volumes:
      - ./node_modules:/mnt/node_modules
  jaeger:
    image: jaegertracing/all-in-one
    ports:
      - "16686:16686"
      - "4317:4317"
      - "4318:4318"

The existing docker-compose.yaml and the newly created docker-compose.override.yaml will be merged, such that the OpenTelemetry Java agent and Node.js package are injected into the services. Once again start the simulation:

docker compose up

This will bring up the three services for the simulation and additionally a container running jaeger. In your browser you can navigate to http://localhost:16686/search to see traces flowing through your system:

Learn more

If you want to learn more about app-simulator and how you can use it for your own needs, we recommend that you continue with the tutorial.