You cannot select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
79 lines
2.6 KiB
JavaScript
79 lines
2.6 KiB
JavaScript
// simple node web server that displays hello world
|
|
// optimized for Docker image
|
|
|
|
var express = require('express');
|
|
// this example uses express web framework so we know what longer build times
|
|
// do and how Dockerfile layer ordering matters. If you mess up Dockerfile ordering
|
|
// you'll see long build times on every code change + build. If done correctly,
|
|
// code changes should be only a few seconds to build locally due to build cache.
|
|
|
|
var morgan = require('morgan');
|
|
// morgan provides easy logging for express, and by default it logs to stdout
|
|
// which is a best practice in Docker. Friends don't let friends code their apps to
|
|
// do app logging to files in containers.
|
|
|
|
// Constants
|
|
const PORT = process.env.PORT || 8080;
|
|
// if you're not using docker-compose for local development, this will default to 8080
|
|
// to prevent non-root permission problems with 80. Dockerfile is set to make this 80
|
|
// because containers don't have that issue :)
|
|
|
|
// Appi
|
|
var app = express();
|
|
|
|
app.use(morgan('common'));
|
|
|
|
app.get('/', function (req, res) {
|
|
res.json({ message: 'Hello Docker World!' });
|
|
});
|
|
|
|
app.get('/healthz', function (req, res) {
|
|
// do app logic here to determine if app is truly healthy
|
|
// you should return 200 if healthy, and anything else will fail
|
|
// if you want, you should be able to restrict this to localhost (include ipv4 and ipv6)
|
|
res.send('I am happy and healthy\n');
|
|
});
|
|
|
|
var server = app.listen(PORT, function () {
|
|
console.log('Webserver is ready');
|
|
});
|
|
|
|
|
|
//
|
|
// need this in docker container to properly exit since node doesn't handle SIGINT/SIGTERM
|
|
// this also won't work on using npm start since:
|
|
// https://github.com/npm/npm/issues/4603
|
|
// https://github.com/npm/npm/pull/10868
|
|
// https://github.com/RisingStack/kubernetes-graceful-shutdown-example/blob/master/src/index.js
|
|
// if you want to use npm then start with `docker run --init` to help, but I still don't think it's
|
|
// a graceful shutdown of node process
|
|
//
|
|
|
|
// quit on ctrl-c when running docker in terminal
|
|
process.on('SIGINT', function onSigint () {
|
|
console.info('Got SIGINT (aka ctrl-c in docker). Graceful shutdown ', new Date().toISOString());
|
|
shutdown();
|
|
});
|
|
|
|
// quit properly on docker stop
|
|
process.on('SIGTERM', function onSigterm () {
|
|
console.info('Got SIGTERM (docker container stop). Graceful shutdown ', new Date().toISOString());
|
|
shutdown();
|
|
})
|
|
|
|
// shut down server
|
|
function shutdown() {
|
|
server.close(function onServerClosed (err) {
|
|
if (err) {
|
|
console.error(err);
|
|
process.exitCode = 1;
|
|
}
|
|
process.exit();
|
|
})
|
|
}
|
|
//
|
|
// need above in docker container to properly exit
|
|
//
|
|
|
|
module.exports = app;
|