Node.js Checkenv Script with Axios
A small Node.js CLI that polls URLs with Axios and reports when a service becomes ready.
2 min read
Updated
A small Node.js health-check utility: it polls a URL with Axios at an interval, retries a configurable number of times and reports whether the service became ready. The files below are the module, the CLI entry point and its package.json.
Health.mjs
javascript
import axios from 'axios';
export default {
check(url, { interval = 5, retries = 3, timeout = 10 } = {}) {
trace.info(`Checking URL ${url}\n`);
return new Promise((resolve) => {
axios.get(url, { timeout: timeout * 1000 })
.then(({ status }) => {
if (status < 400) {
trace.infob(`URL ${url} is up (${status})\n`);
resolve(true);
} else if (retries--) {
trace.infob(`URL ${url} down (${status})... Retrying (${retries}) in ${interval}s...\n`);
setTimeout(() => this.check(url, { interval, retries, timeout }).then((resolve)).catch(resolve), interval * 1000);
} else {
trace.infob(`Unable to reach ${url} (${status})\n`);
resolve(false);
}
})
.catch(({ message }) => {
if (retries--) {
trace.error(`Error when reaching '${url}': ${message}. Retrying (${retries}) in ${interval}s...\n`);
setTimeout(() => this.check(url, { interval, retries, timeout }).then((resolve)).catch(resolve), interval * 1000);
} else {
trace.error(`Error when reaching '${url}': ${message}\n`);
resolve(false);
}
});
});
},
};main.mjs
javascript
import commander from 'commander';
import Healh from './Healh.mjs';
const program = new commander.Command();
program.name('checkenv');
program.version('1.0.0');
program
.requiredOption('-e, --url <url>', 'URL to check')
.option('-t, --timeout <ms>', 'Timeout in ms', '30000')
.action(async () => {
const { url, timeout } = program.opts();
await Healh.check(url, Number.parseInt(timeout));
});
program.parse();package.json
json
{
"name": "checkenv",
"version": "1.0.0",
"description": "Checkenv script",
"main": "main.mjs",
"type": "module",
"scripts": {},
"author": "Sébastien Demanou <demsking@gmail.com>",
"license": "MIT",
"dependencies": {
"axios": "^0.21.1",
"commander": "^7.1.0"
}
}Something wrong or want to discuss this article?
Get in touch