Simple.js

function fauxcapi() {
    var HTTPClient = require('dw/net/HTTPClient');
    var path = decodeURIComponent(request.httpParameterMap.path.stringValue);
    var httpClient : HTTPClient = new HTTPClient();
    httpClient.open('GET', 'https://' + request.httpHost + '/' + path);
    httpClient.setTimeout(5000);
    httpClient.send();
    response.setContentType('application/json');
    var expiryTime = new Date(Date.now());
    expiryTime.setMinutes(expiryTime.getMinutes() + 60);
    response.setExpires(expiryTime);
    response.setStatus(httpClient.statusCode);
    response.writer.print(httpClient.text);
}
fauxcapi.public = true;

exports.Fauxcapi = fauxcapi;