Uptime Kuma reports DOWN, but the service can be accessed
[!TIP]
In case you did not know:
docker has more than one network type with only some of them allowing access to the local network and some not even allowing access to remote networks
If your Uptime Kuma reports DOWN of your service, knowing if it is a bug of Uptime Kuma / a docker network misconfiguration or a firewall is a good start to fixing the issue.
To debug this, go into your container's bash via
docker exec -it uptime-kuma bash
Install curl
apt update && apt --yes install curl
Then you can debug this issue with commands like ping, curl, ...
Examples:
curl https://google.com
ping google.com