rif

0.3.0 • Public • Published

rif

Node.js module to resolve network interfaces.

This modules provides a concise way to extract an IP address from the output of require('os').networkInterfaces().

This is useful for deployments where the environment (e.g. Docker, AWS) picks the IP addresses for you.

Note: use the command line utilities ifconfig or ipconfig to list actual interface names on your system.

Example

var rif = require('rif')()
 
console.log(rif('lo')) // prints IPv4 address of loopback interface: 127.0.0.1
console.log(rif('lo/6')) // prints IPv6 address of loopback interface: ::1
console.log(rif('eth0')) // prints IPv4 address of interface eth0: 10.x.x.x (depends on your system!)
 
console.log(rif('lo/4/netmask=255.0.0.0')) // netmask field must equal 255.0.0.0
console.log(rif('lo/4/netmask^255,internal=true')) // netmask field must start with 255 and internal field must have value true
 
console.log(rif('//address^192.168')) // prints first found address of any interface of any family,
                                      // where address starts with 192.168

You can optionally provide a fixed set of pre-defined interfaces. This useful for testing (see (seneca-mesh/test/mesh.test.js)[github.com/rjrodger/seneca-mesh/blob/master/test/mesh.test.js]).

var rif = require('rif')({
  my_interface: [{
    address: '192.168.1.2'
  }]
})
 
console.log(rif('lo')) // prints IPv4 address of loopback interface: 127.0.0.1
console.log(rif('my_interface')) // prints 192.168.1.2

Syntax

ifname/v/fieldspec

  • ifname: name of network interface.
    • values: * (or empty string): match any; string: match exact interface name
  • v: (optional) IP version: 4 or 6, meaning IPv4 or IPv6 respectively.
    • values: 4: IPv4; 6: IPv6; * (or empty string): match either IP family
  • fieldspec: (optional) comma-separated list of field value tests

The field value tests are of the form: name#value where # is one of:

  • =: exact match.
  • ^: field starts with value.
  • $: field ends with value.
  • %: field contains value.

See unit tests for more examples.

License

Copyright (c) 2016, Richard Rodger and other contributors, MIT License.

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Install

npm i rif

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Version

0.3.0

License

MIT

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  • rjrodger