notification-elements-demo/node_modules/is-inside-container/index.js

import fs from 'node:fs';
import isDocker from 'is-docker';

let cachedResult;

// Podman detection
const hasContainerEnv = () => {
	try {
		fs.statSync('/run/.containerenv');
		return true;
	} catch {
		return false;
	}
};

export default function isInsideContainer() {
	// TODO: Use `??=` when targeting Node.js 16.
	if (cachedResult === undefined) {
		cachedResult = hasContainerEnv() || isDocker();
	}

	return cachedResult;
}