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Save cyrusboadway/5a7b715665f33c237996 to your computer and use it in GitHub Desktop.
| #!/bin/bash | |
| ### Google Domains provides an API to update a DNS "Syntheitc record". This script | |
| ### updates a record with the script-runner's public IP, as resolved using a DNS | |
| ### lookup. | |
| ### | |
| ### Google Dynamic DNS: https://support.google.com/domains/answer/6147083 | |
| ### Synthetic Records: https://support.google.com/domains/answer/6069273 | |
| USERNAME="" | |
| PASSWORD="" | |
| HOSTNAME="yoursubdomain.yourdomain.here" | |
| # Resolve current public IP | |
| IP=$( dig +short myip.opendns.com @resolver1.opendns.com ) | |
| # Update Google DNS Record | |
| URL="https://${USERNAME}:${PASSWORD}@domains.google.com/nic/update?hostname=${HOSTNAME}&myip=${IP}" | |
| curl -s $URL |
@mbbackus, that is a really terrible idea for the fact that your credentials are being passed in this request. Not just any credentials, credentials which gives access to the domains. Which is basically like giving the keys away to the business.
It would be much safer to add the CA cert to the router (this is relatively easy for most routers).
Mainly posting this so others don’t see the comment and just blindly disable SSL verification.
You can also use Google Domains to get your public IP address.
IP=$(curl -s "https://domains.google.com/checkip")
In my Gist, I fetch the current record Google has, and compare it to my public IP before trying to submit an update. I also examine the response and echo out a more detailed status update.
How do I use this if I have more than 1 subdomain?
For the record, all of this is based on the Dyn API developed in the 90s and most vendors support it for dynamic updates. You can check for details here:
Should it work the same way if my agent has a n IPv6 address? Because it doesn't seem to work for me.
The documentation suggests the API supports IPv6 updates.
https://support.google.com/domains/answer/6147083
You may need to modify the script to url-encode the ip address (the colons in particular). Rather than composing the Url as a single string, you could add the data parameters component through curl's method, which will do the encoding:
curl --data-urlencode "myip=${IP}" https://domains.google.com/etc.
Thanks for the quick response.
The .sh script works and returns "good 'my IPv6 address'".
However my domain only works if I am connected in the same network as the server. But is a type my IPv4 address in a browser on a device that is not in the same network it actually works.
I don't know what's the problem.
This will make it IP4
IP=$( curl -4s "https://domains.google.com/checkip" )
Bonus! Clean output
curl -sw '\n' $URL
I think it would be slightly more secure to do this so your username and password are not in plain text (url) provided you're making an HTTPS request:
curl --user ${USERNAME}:${PASSWORD} -s $URL
I did something similar with python, avoiding calls from google domains. Today I have the script running every 5 minutes.
I'm getting badagent when trying to run in macosx terminal
Nevermind fixed it. Changed to use Google domains to get IP
only posting here because i was drawn in by the search engine... never transmit your username and password in anything but TLS and proper TLS... dont be a fool its not worth it in the end.
you can use this for ip address retrieval
currentipaddress="$(wget -q -O - checkip.dyndns.org | sed -e 's/.Current IP Address: //' -e 's/<.$//')"
or you can use this if you are directly connected... change to your correct network interface though
currentipaddress="$(ifconfig eth1 | grep -o "inet addr:([0-9]{1,3}.){3}[0-9]{1,3}" | sed 's/inet addr://')"
and this is the curl request that i have formed and it works perfectly everytime.
curloutput=$(curl -s --data-urlencode "hostname=@.domain.com" --data-urlencode "myip=$currentipaddress" -H "Host: domains.google.com" -u "$username:$password" "https://domains.google.com/nic/update")
echo "$curloutput" to wherever you want
I know this is an old thread but you can just send a request to the URL and not include the IP just pass the username and password.
The API will then use the IP the request was sent from.
e.g.
curl https://username:password@domains.google.com/nic/update?hostname=subdomain.yourdomain.com
For more details see the section at the bottom of this page labelled "Using the API to update your Dynamic DNS record"
https://support.google.com/domains/answer/6147083?hl=en-GB
I had to change line 15 to IP=$( curl ifconfig.me ). Other than that the script works.
A stare is born
Might want to add --insecure option to the curl request as I was unable to get it run otherwise (no ca-certificates on my router).