vim-dnsserial

Another DNS-zone serial number updater.

Why?

I know this not the first vim plugin available to update a DNS-zone serial number. Here is a few reasons why I chose not to use the canonical one:

• there is no license and therefore it is not free;
• it is unmaintained;
• it is bugged;
• it lacks functionalities.

It chose not to fork the original plugin but to write a new one from scratch mainly for legal purposes, but also because I did not found the code as simple as I expected.

Usage

By default, each time you save a bindzone file, the script will look for the DNS serial number and update it. You can also update it without saving the file by invoking the :DNSSerialUpdate function.

Patterns

In order to be detected, the DNS serial number must match one the following pattern:

• YYYYMMDDXX ; serial

  • YYYY is the year (4 digits, must start by either 19 or 2);
  • MM is the month (2 digits);
  • DD is the day (2 digits);
  • XX is any non-negative number (1 or more digits);
  • the word serial is not case-sensitive;
  • there can be any number of blanks on each sides of the semicolon.

• SSSSSSSSSS ; serial

  • SSSSSSSSSS is the UNIX tiemstamp (10 digits, must start by 1);
  • the word serial is not case-sensitive;
  • there can be any number of blanks on each sides of the semicolon.

• XX ; serial

  • XX is any non-negative number (1 or more digits);
  • the word serial is not case-sensitive;
  • there can be any number of blanks on each sides of the semicolon.

According to those patterns, only dates between 1900 and 2999 will be detected; however this should not be a problem at all. Most importantly, only timestamps between September 9 2001 and March 17 2030 will be detected.

Configuration

You can set several configuration variables in your vimrc:

• g:dnsserial_auto_update: Defines whether or not the serial is updated when the zone file is saved (default is 1, set it to 0 to disable).
• g:dnsserial_custom_patterns: List of customs patterns that will be added to the default ones. Order matters, the first matching patters will be used. Customs patterns will be tested before the default ones.
• g:dnsserial_patterns: List of default patterns. It is not advised to change it.

Custom patterns

A pattern is defined by a dictionary with two keys: regex and matching.

regex

Contains the regular expression that will be used to search the document for the serial number. All the components of the serial number must be captured with parenthesis.

matching

This is a list of every components of the serial number. Each component is defined by a dictionary. The type key must be present and contain one of the allowed types. Depending on the type, several additional keys might be defined. Authorized types and their options are:

• raw: Raw string.
• integer: An integer that will be incremented.

• offset (int): set the offset by which the integer is incremented. Default is 1.
• padding (int): Force the integer to be 0-padded on the associated number of digits.
• date_reset (bool): If set to 1 and a the serial contains a date, the integer will be reseted to 0 if the date is updated. Default is 0.

• date: A formated date that will be updated to the current one.

• fmt (string, mandatory) : the date format according to the strftime() specifications. See :help strftime for more details.

examples

A simple pattern matching a serial defined as an integer and followed by a comment starting by the word serial is:

{
  'regex': '\(\d\+\)\s*;\s*\cserial',
  'matching': [
    {'type': 'integer'}
  ]
}

The same example, but having the serial number starting by the current date (YYYYMMDD) and the integer padded on two digits:

{
  'regex': '\(\d\{8}\)\(\d\+\)\s*;\s*\cserial',
  'matching': [
    {'type': 'date', 'fmt': '%Y%m%d'},
    {'type': 'integer', 'padding': 2, 'date_reset': 1}
  ]
}