1-two-services.md

Tutorial 1: Two services

Note

This tutorial is work in progress.

Make sure that you have either completed the docker compose or kubernetes quick start.

In this tutorial you will learn more about the structure of an application simulation configuration (app sim config) and how you can influence the behavior of your services.

Create a new empty directory, in this directory, create a config.yaml file with the following content:

services:
  frontend:
    type: java
    endpoints:
      http:
        /list:
          - http://backend/list/items
  backend:
    type: java
    endpoints:
      http:
        /list/items:
          - slow,1024
loaders:
  user1:
    type: curl
    wait: 5
    sleep: 1
    urls:
      - http://frontend/list

This configuration file defines two services and one loader:

1. The service frontend is a Java-based application, that provides an HTTP endpoint called /list. When this endpoint gets called, it will send a HTTP request to the URL http://backend/list/items
2. The service backend is also a Java-based application that provides an HTTP endpoint, called /list/items. When this endpoind gets called, it will some "slow" code for ~1024 milliseconds.
3. The loader user1 is a curl-based load generator. It will wait 5 seconds after start up and then call the URL http://frontend/list repeatedly. It will wait 1 second between each call.

Use your preferred generator to deploy this simulation:

• For docker compose run

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

• For kubernetes run

  docker run --rm -t -i -v ${PWD}/deployments:/app/deployments -v ${PWD}:/mnt ghcr.io/cisco-open/app-simulator-generators-k8s:latest --config /mnt/config.yaml
  kubectl apply -f deployments/