Solution for DDNS-Server on Virtualmin ? + Proposal to add command --modify-record-with-ttl to virtualmin modify-dns

Hi Webmin/Virtualmin team, and happy new year!

This is a feature-request for implementing efficient DDNS server scripts on a webmin server with DNS server running:

Most routers have, in addition of DynDNS support, a “custom” HTTP/HTTPS call to update their changing public IP address in a DNS record.

Ideally, it would be nice to have a DynDNS-like server implementation in Webmin with a GUI (maybe simpler than the GUI of the community-made B9DDNS module referred to at bottom).

But at least, it would be cool to have a cli command:

virtualmin modify-dns –modify-record-with-ttl "name type TTL value"

in addition of the --add-record-with-ttl and the --remove-record commands.

This allows to implement this DDNS-updates server with a single virtualmin-command instead of two, and would avoid two updates of slave DNS servers, with a moment without any DNS records at all between remove-record and add-record:

I also found this old project for a DDNS-server module, but seems unmaintained and non-official, so I’m not installing it:

with detailed explanation here:

I also found this thread that wasn’t understood at that time but got auto-closed in the mean time:

For whoever might need it, I am sharing here a small quick and half-dirty DDNS implementation for Virutalmin in PHP, that I developed based on the one referred to above, the gist forked on github:

  • It allows updating or deleting IPv4 and/or IPv6 addresses
  • It is protected by a codephrase
  • All arguments are security-cleaned
  • It mails IP addresses changes and lack of updates
  • It logs changes only

It is here for Virtualmin’s community’s free usage:

The first file goes into the public_html directory, while the second one goes outside of it and should be called by a cron.


Nice one - many thanks beat!

In second file ddns-cron.php the const def for LOG_FILE is missing and one should know that the 3 defined files need to exist already with right owners/rights.

After that its working like a charm and suits perfectly my needs.

Thanks again!

You are welcome and thank you, @Appovis, for the feedback. Indeed when I adapted the constants for publishing that const LOG_FILE disappeared by mistake.

Scripts create the files if they have the write permissions to those folders, but if not then they need to be setup.

I have updated my gist above with your feedbacks. Hope that the Virtualmin @team will be implementing something nice and user-friendly one day, and also add a line command to update a DNS entry instead of having to remove and add the entry, which with multiple slave servers takes a few seconds to reload all Bind DNS servers.

Hey @beat - got some more feedback…

DDNS_DOMAIN is not in sync as backend attaches DOMAIN_POSTFIX prefix while front end doesn’t. for my needs I just got rid of DOMAIN_POSTFIX from backend and all cool.

also it seams like there is an issue with delete requests - they got thrown from the data files but not deleted from DNS Zone - didn’t had time to look into yet but guess will be a quick fix too… feedback follows once I had time to look into it.

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