terminus
Adds graceful shutdown and Kubernetes readiness / liveness checks for any HTTP applications.
Installation
Install via npm:
$ npm i @godaddy/terminus --save
Usage
const http = require('http');
const terminus = require('@godaddy/terminus');
function onSignal () {
console.log('server is starting cleanup');
return Promise.all([
// your clean logic, like closing database connections
]);
}
function onShutdown () {
console.log('cleanup finished, server is shutting down');
}
const server = http.createServer((request, response) => {
response.end(
`<html>
<body>
<h1>Hello, World!</h1>
</body>
</html>`
);
})
const options = {
// healtcheck options
healthChecks: {
'/healthcheck': check // a promise returning function indicating service health
},
// cleanup options
timeout: 1000, // [optional = 1000] number of milliseconds before forcefull exiting
signal, // [optional = 'SIGTERM'] what signal to listen for relative to shutdown
onSignal, // [optional] cleanup function, returning a promise (used to be onSigterm)
onShutdown, // [optional] called right before exiting
// both
logger // [optional] logger function to be called with errors
};
terminus(server, options);
server.listen(PORT || 3000);
With express
const http = require('http');
const app = express();
app.get('/', (req, res) => {
res.send('ok');
});
const server = http.createServer(app);
const options = {
// opts
};
terminus(server, options);
server.listen(PORT || 3000);
With koa
const http = require('http');
const Koa = require('koa');
const app = new Koa();
const server = http.createServer(app.callback());
const options = {
// opts
};
terminus(server, options);
server.listen(PORT || 3000);
Limited Windows support
Due to inherent platform limitations, terminus
has limited support for Windows.
You can expect SIGINT
to work, as well as SIGBREAK
and to some extent SIGHUP
.
However SIGTERM
will never work on Windows because killing a process in the task manager is unconditional, i.e., there's no way for an application to detect or prevent it.
Here's some relevant documentation from libuv
to learn more about what SIGINT
, SIGBREAK
etc. signify and what's supported on Windows - http://docs.libuv.org/en/v1.x/signal.html.
Also see https://nodejs.org/api/process.html#process_signal_events.