State monitoring of external service via HTTP request

🟢 Beginner

script

This tutorial will guide you through creating a script that periodically checks whether an external HTTP service is available. The script runs every 5 seconds and reports the service’s status as a boolean value (true for available, false for unavailable).

Define a boolean value and link it to a script via owner.scripts.
Schedule the script to execute every 5 seconds using detached.scripts.
Send an HTTP GET request in JavaScript and set the value to true or false based on the response.

git checkout origin/osp-scripts-configuration .
git checkout origin/example-scripts-external-system-monitoring .

Prerequisites

A website that responds to HTTP requests.

Steps

1. Create a script that generates an integer value and runs every 5 seconds.

root/examples/scripts/external-service/status/value.ospp

{
    "name": "Service status",
    "description": "The status of an external service",
    "type": "BOOLEAN"
}

root/examples/scripts/external-service/status/owner.scripts

{
    "moduleId": "modules.scripts.scripts-1",
    "scheduledExecutions": ["0/5 * * ? * * *"],
    "accessedValues": [],
    "sourceFile": "root/scripts/external-service/status/script.js"
}

2. Create a script that sends an HTTP GET request to an external service and retrieves the response.

root/examples/scripts/external-service/status/script.js

main();

function main() {
    let result = http.doGet("http://localhost:8080/person/1");
    if (!result.isSuccess()) {
        log.warn("The service is unavailable cause [{}].", result.getError());
    }

    return result.isSuccess();
}