systemd-socket

systemd sockets for node.js applications

Systemd Socket Activation

A minimalistic NodeJS module to provide access to systemd based socket activation. It is similar to node-systemd, but it differs in two points:

Monkey-Patching violates separation of concerns. This module does not need to modify interna of NodeJS.

The API is more explicit about the way the socket is chosen. There is no manual way of finding out whether or not the application is running with NODE_ENV=production. You just tell your app “use a systemd socket or my default”.

var http = require('http');
var systemdSocket = require('systemd-socket');

var server = http.createServer();
// set up handlers for error and request events
server.listen(systemdSocket() || 8080);

Create a handle for a server to listen at. Returns a structure like {fd: <fd>} to be passed to calls like http.Server.listen().

The function will return null if there is no socket to listen to. This way you can easily use || to provide a default value (i.e. just as in the aforementioned example).

You can use the index argument to select the file descriptor passed to your application. If you expect more than one, you can call systemdSocket() many times to return the handles. Just stop iterating when it returns null (create your own loop and use an index counter starting at 0 and couting up until systemSocket(index) returns null).

Permission to use, copy, modify, and/or distribute this software for any purpose with or without fee is hereby granted, provided that the above copyright notice and this permission notice appear in all copies.

THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.