appengine/metadata/flexible/server.js (38 lines of code) (raw):
// Copyright 2017 Google LLC
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.
'use strict';
// [START gae_flex_metadata]
import express from 'express';
import fetch from 'node-fetch';
const app = express();
app.enable('trust proxy');
const METADATA_NETWORK_INTERFACE_URL =
'http://metadata/computeMetadata/v1/' +
'/instance/network-interfaces/0/access-configs/0/external-ip';
const getExternalIp = async () => {
const options = {
headers: {
'Metadata-Flavor': 'Google',
},
json: true,
};
try {
const response = await fetch(METADATA_NETWORK_INTERFACE_URL, options);
const ip = await response.json();
return ip;
} catch (err) {
console.log('Error while talking to metadata server, assuming localhost');
return 'localhost';
}
};
app.get('/', async (req, res, next) => {
try {
const externalIp = await getExternalIp();
res.status(200).send(`External IP: ${externalIp}`).end();
} catch (err) {
next(err);
}
});
const PORT = parseInt(process.env.PORT) || 8080;
app.listen(PORT, () => {
console.log(`App listening on port ${PORT}`);
console.log('Press Ctrl+C to quit.');
});
// [END gae_flex_metadata]
export default app;