allocate a file descriptor to listen on a port later
npm install tcp-bindallocate a file descriptor to listen on a port later
This is handy if you want to run a server on a low port but want to drop
privileges as soon as possible.
Here we allocate a file descriptor for tcp port 80 and then drop permissions
right away:
`` js
var http = require('http');
var alloc = require('tcp-bind');
var fd = alloc(80);
process.setgid(process.argv[3]);
process.setuid(process.argv[2]);
var server = http.createServer(function (req, res) {
res.write('uid=' + process.getuid() + '\n');
res.end('gid=' + process.getgid() + '\n');
});
server.listen({ fd: fd });
`
Now we're listening on port 80, but the rest is running under a regular user:
`
$ sudo node drop.js substack cdrom &
[1] 2855
$ curl localhost
uid=1000
gid=24
` js`
var alloc = require('tcp-bind')
Allocate a file descriptor to listen on port at an ipv4 or ipv6 string addressaddr.
You can create a tcp server from the file descriptor fd later by passing it to.listen()
the server's method:
`
server.listen({ fd: fd })
This method throws when the port is already bound and when the current user
doesn't have permission to open the port requested.
With npm do:
`
npm install tcp-bind
MIT