6 ms·

Show HN: A simple-to-update dynamic DNS service

30 points by stevekemp 12y ago

tsangk 12y ago
Simple and to the point. Truth be told I've always wanted something like this for my own domains, so that I can point to a home machine, but was too lazy to set it up. Thanks for throwing this out here!
- stevekemp 12y ago
  You're welcome. Initially it was put together as a learning experience, but I can see that it is useful enough to remain live indefinitely. I can imagine several way of monetizing it, such as adding the MX/SRV/TXT/CNAME records, etc. But the one that seems most useful would be allowing custom domain - and sadly I can't see how to do that easily. (I can't imagine somebody would trust me with their root-domain, basically. And having *.foo.example.com seems like it would be long enough to spoil the utility.)
  - desufnoc 12y ago
    I can't imagine somebody would trust me with their root-domain, basically. The “root-domain” is the domain name with a single zero-length label at the top of the hierarchy. What you're referring to is a zone.
    - stevekemp 12y ago
      I thought context would make that clear, but yes you're correct.
      - desufnoc 12y ago
        Yes it is from the context that I inferred what you're talking about. I didn't mention it to pick, but because the DNS is littered with misunderstandings and I think that's part of what holds it back.
ivan_ah 12y ago
Nice! Setting up my server to update every hour was as simple as: crontab -e and adding the line: 31 * * * * curl http://dhcp.io/set/99351a76-f6... (the above job will run on the 31st minute of every hour)
- yohanatan 12y ago
  Do you really want to have to wait up to an hour if your IP address changes and you're away from home?
  - desufnoc 12y ago
    I wonder if there's any utilities that use UPnP or NAT-PMP to monitor for an address change and invoke a script when one is detected.
  - firvulag 12y ago
    Last time I did this on Linux, it was in an if.up script, so when the PPP interface comes up it updates the DNS.
- stevekemp 12y ago
  Cool. I suspect that you'll want to hide STDOUT, if not STDERR. If you're ever dual-homed you might also want to consider adding an explicit "-4", or "-6" in there.
fiatjaf 12y ago
Why didn't anyone build this before?
- stormbrew 12y ago
  Serious question? People build them all the time. They don't tend to stay simple or they eventually start demanding payment. It seems like this is a low cost thing to run, but if it takes off it gets very expensive.
  - stevekemp 12y ago
    I'm hosting the actual records on Amazons Route53 so it is very low cost to run. That said I am looking at monetizing, via additions which require either a low yearly fee, or a lifetime membership price (low). The hard part is seeing what people will consider useful enough. One name for free, without monthly logins being required must always be true. But I could imagine raising the standard TTL to 600 seconds, and keeping 60s for the premium users, adding MX record support, etc.
    - dsl 12y ago
      I've been involved with a number of DNS related companies and projects. Your biggest cost sink will be abuse. Some peddler of illicit images or terror group will set up camp, Amazon will take down all of your records. You'll realize you need to run your own infrastructure. You setup a few boxes. Someone starts selling fake rolexes and your boxes get taken offline. You move them to a friendlier host. A HYIP gets setup under your domain and they don't pay someone, which results in a 150 Gbps DDoS attack. The FBI shows up. You get cynical dealing with the lowest scum of the internet on a regular basis. People are constantly asking for new features and unwilling to pay. You're funding the whole thing out of pocket. Eventually Dyn shows up and offers to take the whole thing off your hands. A year later they shut it down. Some guy on Hacker News announces some Dynamic DNS or free DNS hosting provider, and you smirk to yourself.
      - stormbrew 12y ago
backwardm 12y ago
Thanks for building this! I set up something like this with dyndns for my Raspberry Pi, but thought it was silly that I had to log in every n days to keep the account active.
zapt02 12y ago
Can you open source this? Would be great for other people wanting to run similar services.
- jms_ 12y ago
  From http://dhcp.io/faq/ http://dhcp.io/faq/ > But either way if you find this service useful you can clone the source-code from Github[0], and run your own instance. [0]: https://github.com/skx/dhcp.io/ https://github.com/skx/dhcp.io/
- stevekemp 12y ago
  As per the other reply, this is open. Can I ask why you want it to be open though? Do you not trust the site/me to exist in the future? Or do you not want to rely on something external?
mattbillenstein 12y ago
How do you handle ipv4/ipv6? Seems this is listing my ipv4 address, but not ipv6...
- shornlacuna 12y ago
  It's in the FAQ, you use the -4 or -6 parameters to curl to force it to connect one way or the other, and that controls which address gets updated. (Of course your IPv6 connectivity to dhcp.io has to work properly, but it certainly works both ways for me).
latchkey 12y ago
CloudFlare has a (free) DNS api too. Pretty easy to script something with their system. https://www.cloudflare.com/docs/client-api.html https://www.cloudflare.com/docs/client-api.html
mherrmann 12y ago
Very cool. If anybody needs a Python implementation: https://gist.github.com/anonymous/02257ea2ccf776c1a32e https://gist.github.com/anonymous/02257ea2ccf776c1a32e

30 points by stevekemp 12y ago

Simple and to the point. Truth be told I've always wanted something like this for my own domains, so that I can point to a home machine, but was too lazy to set it up. Thanks for throwing this out here!

stevekemp 12y ago
You're welcome. Initially it was put together as a learning experience, but I can see that it is useful enough to remain live indefinitely. I can imagine several way of monetizing it, such as adding the MX/SRV/TXT/CNAME records, etc. But the one that seems most useful would be allowing custom domain - and sadly I can't see how to do that easily. (I can't imagine somebody would trust me with their root-domain, basically. And having *.foo.example.com seems like it would be long enough to spoil the utility.)
- desufnoc 12y ago
  I can't imagine somebody would trust me with their root-domain, basically. The “root-domain” is the domain name with a single zero-length label at the top of the hierarchy. What you're referring to is a zone.
  - stevekemp 12y ago
    I thought context would make that clear, but yes you're correct.
    - desufnoc 12y ago
      Yes it is from the context that I inferred what you're talking about. I didn't mention it to pick, but because the DNS is littered with misunderstandings and I think that's part of what holds it back.

ivan_ah 12y ago

Nice! Setting up my server to update every hour was as simple as: crontab -e and adding the line: 31 * * * * curl http://dhcp.io/set/99351a76-f6... (the above job will run on the 31st minute of every hour)

yohanatan 12y ago
Do you really want to have to wait up to an hour if your IP address changes and you're away from home?
- desufnoc 12y ago
  I wonder if there's any utilities that use UPnP or NAT-PMP to monitor for an address change and invoke a script when one is detected.
- firvulag 12y ago
  Last time I did this on Linux, it was in an if.up script, so when the PPP interface comes up it updates the DNS.
stevekemp 12y ago
Cool. I suspect that you'll want to hide STDOUT, if not STDERR. If you're ever dual-homed you might also want to consider adding an explicit "-4", or "-6" in there.

fiatjaf 12y ago

Why didn't anyone build this before?

stormbrew 12y ago
Serious question? People build them all the time. They don't tend to stay simple or they eventually start demanding payment. It seems like this is a low cost thing to run, but if it takes off it gets very expensive.
- stevekemp 12y ago
  I'm hosting the actual records on Amazons Route53 so it is very low cost to run. That said I am looking at monetizing, via additions which require either a low yearly fee, or a lifetime membership price (low). The hard part is seeing what people will consider useful enough. One name for free, without monthly logins being required must always be true. But I could imagine raising the standard TTL to 600 seconds, and keeping 60s for the premium users, adding MX record support, etc.
  - dsl 12y ago
    I've been involved with a number of DNS related companies and projects. Your biggest cost sink will be abuse. Some peddler of illicit images or terror group will set up camp, Amazon will take down all of your records. You'll realize you need to run your own infrastructure. You setup a few boxes. Someone starts selling fake rolexes and your boxes get taken offline. You move them to a friendlier host. A HYIP gets setup under your domain and they don't pay someone, which results in a 150 Gbps DDoS attack. The FBI shows up. You get cynical dealing with the lowest scum of the internet on a regular basis. People are constantly asking for new features and unwilling to pay. You're funding the whole thing out of pocket. Eventually Dyn shows up and offers to take the whole thing off your hands. A year later they shut it down. Some guy on Hacker News announces some Dynamic DNS or free DNS hosting provider, and you smirk to yourself.
    - stormbrew 12y ago

backwardm 12y ago

Thanks for building this! I set up something like this with dyndns for my Raspberry Pi, but thought it was silly that I had to log in every n days to keep the account active.

zapt02 12y ago

Can you open source this? Would be great for other people wanting to run similar services.

jms_ 12y ago
From http://dhcp.io/faq/ http://dhcp.io/faq/ > But either way if you find this service useful you can clone the source-code from Github[0], and run your own instance. [0]: https://github.com/skx/dhcp.io/ https://github.com/skx/dhcp.io/
stevekemp 12y ago
As per the other reply, this is open. Can I ask why you want it to be open though? Do you not trust the site/me to exist in the future? Or do you not want to rely on something external?

mattbillenstein 12y ago

How do you handle ipv4/ipv6? Seems this is listing my ipv4 address, but not ipv6...

shornlacuna 12y ago
It's in the FAQ, you use the -4 or -6 parameters to curl to force it to connect one way or the other, and that controls which address gets updated. (Of course your IPv6 connectivity to dhcp.io has to work properly, but it certainly works both ways for me).

latchkey 12y ago

CloudFlare has a (free) DNS api too. Pretty easy to script something with their system. https://www.cloudflare.com/docs/client-api.html https://www.cloudflare.com/docs/client-api.html

mherrmann 12y ago

Very cool. If anybody needs a Python implementation: https://gist.github.com/anonymous/02257ea2ccf776c1a32e https://gist.github.com/anonymous/02257ea2ccf776c1a32e