dsnet/contrib/dsnet-nsupdate

dsnet-nsupdate

A script to maintain an up-to-date DNS zone based on dsnetreport.json. It does this by comparing what is currently in DNS (aided by creating a list of peers in a TXT record in the DNS zone), compared with what needs to be in DNS based on dsnetreport.json. It supports both forward and reverse records for IPv4 and IPv6, and can optionally update an external nameserver in a split-horizon configuration.

Dependencies

• dnspython
• colorlog for colourful logging messages

Usage

The majority of data is obtained from dsnetreport.json, but can be overridden by specifiying it directly in dsnet-nsupdate. It should be run directly with the path to dsnetreport.json as it's only argument.

The script uses a TXT record in the zone to maintain a list of what records have been placed there by it. Each time it is run, it queries this list, and then performs more queries on each hostname in this list to determine what is currently in DNS. It then parsesdsnetreport.json to determine what SHOULD be in DNS. It then compares the two and updates as neccessary via TSIG authenticated dynamic updates.

The default TTL for entries maintained by this script is 300. If whilst comparing data in DNS it finds an entry with a TTL of over this, it will assume that this is taken by something else and will assign a '-dsnet' suffix to the hostname before putting it in DNS. It will also determine if a subzone has been delegated to a peer (by way of an NS record for that hostname) and ignore it if this is the case.