Dynamic DNS from two different locations?
reddit / selfhosted

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nightmareFluffy · 2023-11-04 22:04

I have a website (let's say example.com) where I have subdomains, like
video.example.com and files.example.com, coming from two different
locations. One from work, one from home.

How do I set up dynamic DNS from two locations pointing to one domain?
I looked into Cloudflare Dynamic DNS, but it has a line in the compose
file where it asks about domain, and I don't want it to hijack all the
subdomains to that IP address. I'm currently using a different A
record for each subdomain.

One thing I thought about was using Tailscale somehow to solve this.
But I wouldn't even know where to start.

I'm not sure if any of this matters, but for the sake of completeness:

-Both IP addresses are using Nginx to send traffic to example.com

-One of the IP addresses is also using Cloudflare tunnels for some of
the subdomains. I'm not worried about those; they never break when the
public IP address changes.

-One of the IP addresses (home) is mostly for playing around and
trying new things. But it does have one important thing on it (home
security cameras), so I don't want to break it if I don't have to.

-I prefer to use the [Cloudflare
DDNS](https://hub.docker.com/r/oznu/cloudflare-ddns/) so everything is
with one provider, and there are fewer points of failure. The domain
is registered with Cloudflare. But I'll try other stuff if there's no
way to do it.

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tech2but1 · 2023-11-04 22:22

I think you have "from" and "to" mixed up here somewhere so I got lost
in your issue.

Assuming you just want video.example.com to go to home and
files.example.com to go to work then just set a CNAME on
video.example.com to the DDNS address for the home service and the
CNAME on files.example.com to the DDNS address of the work service.

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nightmareFluffy · 2023-11-04 22:34

Apologize, I think I have "to" and "from" mixed up myself. I think of
the services coming "from" either work or home and going "to" the
domain. I might have that backwards.

Anyway, I'll give that a shot. I thought CNAMEs were always something
like @, but maybe it's a weird code I need to put in. I'll have to
experiment. I'm kind of new to CNAMEs.

Thanks for the advice!

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tech2but1 · 2023-11-04 22:38

A CNAME is just a "forward to" entry. So a CNAME of ```my-home.no-
ip.com``` on ```files.example.com``` would just tell anyone visting
```files.example.com``` to go to ```my-home.no-ip.com```.

Kind of like a standard A record but giving the requester a domain
name instead of an IP. No funky symbols needed!

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JuvenoiaAgent · 2023-11-04 22:58

Better version of Cloudflare DDNS:
https://hotio.dev/containers/cloudflareddns/

You can update multiple entries (subdomains in your case). Run an
instance of it on each server and update its relevant subdomains.

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clintkev251 · 2023-11-04 23:05

@ generally represents the zone apex, so if your zone was domain.com,
using @ would mean just domain.com. If you use a value like foo, the
cname would be for foo.domain.com. Funnily enough, @ actually isn’t
technically allowed for cnames, but a lot of DNS providers fake it by
tuning those into A records instead

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nightmareFluffy · 2023-11-04 23:24

This looks awesome, and it might solve my problem! Thanks for sending!
Great community here.

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nightmareFluffy · 2023-11-05 00:30

Huh, never knew that. Interesting tidbit about the @.

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nightmareFluffy · 2023-11-06 14:02

Great explanation!