Network-Interfaces-Script (Ver 1.3)

Read and update awk scripts for Ubuntu /etc/network/interfaces file.

• readInterfaces.awk -- parse and output interface configuration
• changeInterface.awk -- modify interfaces file

Parse Interfaces Script

Complete re-implement both scripts with much simpler logic, shorter code and pack with more flexible features. It now allows you to add/modify/delete interfaces, as well as add/modify/delete any settings within an interface. These scripts are tested with testChangeInterface.py python script.

Update Interfaces Script (changeInterface.awk)

Here is the standard usage for changeInterface.awk:

awk -f changeInterface.awk <interfaces file> <device=ethX> 
     <mode=(dhcp|static|manual)> [action=add|remove] [version=ipv4|ipv6] 
     [address=<ip addr> netmask=<ip addr> <name=value> ...]

• device=ethX - target network interface to configure
• mode=(dhcp|static|manual) - type of network interface to configure. This argument is not required when action is remove
• action=(add|remove) - optional argument. Add or remove an interface entry. If this argument is not specified, it assumes modify operation
• version=(ipv4|ipv6) - optional argument. Choose the ip protocol version. If this argument is not specified, it assumes ipv4 operation
• name=value - configuration for a network interface. The script doesn't limit what settings as long as in name and value syntax. For example:
  • network=192.168.0.0 - modify (if already exists) or add the network setting
  • network= - specify without value means to remove the network setting if already exists
  • 'dns-nameservers=192.168.200.5 10.0.10.1' - for settings with multiple values, enter with quote around it. Or you can use dns=192.168.200.5 as short form.

Usage Examples:

Configure network device eth0 to DHCP mode

awk -f changeInterfaces.awk /etc/network/interfaces device=eth0 mode=dhcp

Add a network device p3p1 with static settings

awk -f changeInterfaces.awk /etc/network/interfaces device=p3p1 action=add mode=static address=192.168.202.1 netmask=255.255.255.0 gateway=192.168.202.254

If p3p1 already exists and configured as DHCP, it will automatically modify to static interface with all the input settings.

If p3p1 already exists and configured as static, it will overwrite the existing field or add the field if it is new.

Delete an interface entry

awk -f changeInterfaces.awk /etc/network/interfaces device=eth1 action=remove 

Remove network & broadcast fields and add (or modify if exists) dns-nameservers & foo fields

awk -f changeInterfaces.awk /etc/network/interfaces device=eth1 mode=static network= broadcast= foo=bar 'dns-nameservers=10.0.10.1 192.168.200.5 192.168.202.254'

Read Interfaces Script (readInterfaces.awk)

Here is the standard usage for readInterface.awk:

awk -f readInterfaces.awk <interfaces file> <device=ethX> [output=all]

• output=all - print out the full settings for an interface. Without this option, the script will just print out the basic address config in : ipaddr netmask gateway (separated with a single white space). With this option, all the settings are displayed, e.g.

192.168.0.10 255.255.255.0 192.168.0.1
bridge_maxage 12
broadcast 192.168.0.255
network 192.168.0.0
bridge_stp off
bridge_fd 9
bridge_ports eth0
bridge_hello 2