Gotify (Domain) Expiration Alerter (GEA) is a docker service that checks if a domain's registration expires in less than N days. If yes, an alert is sent to your Gotify instance.
Additionally, it exposes a web server that serves JSON statuses of any domain being monitored. This is handy for:
- Uptime Kuma: monitor and alert via existing means when your domain(s) expire
- Home Assistant: show days until your domain(s) expire
Here's what it looks like to get alerts acknowledging GEA is started in Gotify (top) and showing the logs in Docker (bottom):
Maybe!
There's number of existing projects that might meet your needs. Check there first.
Continue on if you want to run a small docker service, only have a few domains to monitor and use Gotify for alerts (and possibly Home Assistant and/or Uptime Kuma).
- Check out this repo:
git clone https://github.com/mrjones-pliop/GEA.git - Copy the
exmple.envto.env - Log into your Gotify instance and create a token
- Edit
.envto have your Gotify URL, Gotify token and domain(s) you want to monitor. Be sure that you updateGOTIFY_URLbe your Gotify URL and that it is accessible from your docker instance. :GOTIFY_URL="http://172.17.0.1:8000" GOTIFY_TOKEN="A.T9cF1UxmSU6J9" SEND_ALERTS=Yes-please! # delete this line to not send alerts MONITOR_DOMAINS="github.com, plip.com" WARN_DAYS=10 PORT=9080
- Start docker to begin domain monitoring:
docker compose up -d - You should get a confirmation alert that monitoring is set up and when the domain(s) will expire so you know everything is working. As well, on port
9080of your docker host, there is now a web server running.
- Check out this repo:
git clone https://github.com/mrjones-pliop/GEA.git - Copy the
exmple.envto.env - Edit
.envto have your domain(s) you want to monitor. Be sure to delete theSEND_ALERTSline so that no Gotify calls are made. You can leaveGOTIFY_URL,GOTIFY_TOKENandWARN_DAYSas is - they will be unused:GOTIFY_URL="http://172.17.0.1:8000" GOTIFY_TOKEN="A.T9cF1UxmSU6J9" MONITOR_DOMAINS="github.com, plip.com" WARN_DAYS=10 PORT=9080
- Start docker to begin domain monitoring:
docker compose up -d - On port
9080of your docker host, there is now a web server running.
After you've called docker compose up -d, a web server starts on port 9080. There's a file per domain in MONITOR_DOMAINS. If you were monitoring github.com you would add on .json to see the results. Here's a call of curl piped to jq to show the results:
curl -qs http://172.17.0.1:9080/github.1485827954.workers.dev.json | jq
The output is:
{
"date": "2026-10-09 18:20:50",
"days": 434,
"domain": "github.com",
"cached_date": "2025-08-01 16:18:56.393527"
}If you run Home Assistant you can have a list of domain expirations that looks like this:
I'm not the most savvy HA user, but by referencing their RESTful API docs I was able to cobble together this config which I could then use to add to a dashboard (as shown above):
rest:
- scan_interval: 3600
resource: http://172.17.0.1:9080/plip.com.json
sensor:
- name: "Plip"
value_template: "{{ value_json['days'] }}"
state_class: measurement
unit_of_measurement: 'days'
- scan_interval: 3600
resource: http://172.17.0.1:9080/github.1485827954.workers.dev.json
sensor:
- name: "Github"
value_template: "{{ value_json['days'] }}"
state_class: measurement
unit_of_measurement: 'days'For the resource, be sure to use the URL or IP for where your GEA is running via docker.
If you run Uptime Kuma you can monitor and alert on your domain expirations. Here I've set it to alert to one more day than the domain is valid for (435) so the alert is triggered:
This done using the JSON values feature. When adding a new monitor, I used these values:
- Monitor Type:
HTTP(s) Json Query - URL:
http://172.17.0.1:9080/github.1485827954.workers.dev.json- Be sure to use the URL or IP for where your GEA is running via docker. As well, specify the domain you want to alert on -github.1485827954.workers.devis shown here. - Json Query:
days.$number()<10- Set the10to be the days remaining in the domain before it sets an alert. - Expected Value:
false
All other values are OK at their defaults.
This project is really just glue between a few existing solutions. By leveraging actively developed libraries around the whois service, hopefully it will work for a large collection of domains:
- Alerts: Gotify
- Expiration from
whois: Pythonwhoislibrary - Infra: Docker Compose
- OS 1: Python 3 Alpine 3.21 image (only 16MB \o/) - this to use the
whoislibrary and cache the results - OS 2: Busybox latest image (only 2MB!!! \o/) - this to serve up the cached JSON files
My partner suggests, "A whole Docker app?! What about just setting a yearly Task reminder in Google - that'll only take 30 seconds to do." This may be the simplest way forward!
Otherwise, I was unable to find an existing docker based service to easily send an alert to Gotify when a domain is expiring. There's a Go based project "domain-monitor" that does 100% of everything I was looking for, but sends email alerts instead of Gotify alerts. If you want email alerts, I suspect this would be the way to go. It looks be very mature having started in 2020 and is on version 1.24 as of now (Jul 2025). I don't know Go, so not easy for me to extend :/
Another good idea might to use Nagios - a gold standard in monitoring.
A very full-featured self-hosted solution is likely DomainMOD which appears to do it all and then some, but is geared towards managing dozens, or more, of domains.
There's some SaaS offerings that appear to do it:
Then there are GH projects I saw but passed over as they're older or too broad scoped :
- alertmanager_gotify_bridge
- Nice Domain
- Domain Hunter
- xcname
- dns-domain-expiration-checker
- action-check-domain
- pythonwhois
Existing, similar DIY solutions have you write python and, well, here I am DIYing it for you so you don't have to DIY ;)