Hi all, I selfhost private instance of Lemmy for my friends behind Pangolin reverse proxy. I noticed something interesting in the logs; Lemmy specifically gets pinged / tried to access each midnight UTC from what looks like an IP from inside the network. Just out of curiosity, do you have any idea what that could be? I have federation off and private instance on, but maybe it is something from Lemmy network checking if my server is alive? Thank you in advance
Update: So it turns out I was perhaps correct with my hunch. The local IP turns out to be the proxy I set for ports 80 and 443 (it was internal Wireguard IP). Unfortunately my current setup did not allow me to catch which IP the request came from (which is a problem I have to solve later) but the lemmy-proxy container got requests for GET /.well-known/nodeinfo and GET /nodeinfo/2.1. So it is probably something checking my server, likely from the Lemmy network.
Update 2: So after I disabled Pangolin for one night, after I reenabled it, the requests do not come again! So the Lemmy network must have figured out that my instance is set to private and stopped pinging.
- Sounds like either federation working as intended, or some client app trying to cache info about your instance. Might be https://fedidb.com/ or https://fediverse.observer/ or some other service. 
- Is your server running on UTC? Depending on your location midnight UTC could also be 8 AM and it could be a user with a very regular morning schedule. - Only you can find out which machine is sending this request… - My timezone is CET, so I get the ping on 2AM. The Lemmy container should be on UTC as I did not specify the timezone when launching the container. It is definitely not human, as the ping comes exactly on midnight UTC, or seconds away from midnight. I will turn off the Pangolin auth and investigate further this midnight. Again sorry for not providing more information, I was certain that it is a thing internal to Lemmy and I was just curious what it is 
 
- Update: So it turns out I was perhaps correct with my hunch. The local IP turns out to be the proxy I set for ports 80 and 443 (it was internal Wireguard IP). Unfortunately my current setup did not allow me to catch which IP the request came from (which is a problem I have to solve later) but the lemmy-proxy container got requests for GET /.well-known/nodeinfo and GET /nodeinfo/2.1. So it is probably something checking my server, likely from the Lemmy network. 
- How could we tell you about an IP inside your own network? Look at the host using that IP and see what’s running on it. - Well it is definitely specific to Lemmy, I selfhost over 20 services and only Lemmy gets pinged on midnight. The only other service I saw doing this was Nextcloud, Nextcloud instance needs to reach itself, but for Lemmy it is a different IP, which is puzzling me 
 
- Got the log? - Nothing in Lemmy’s logs, in Pangolin’s logs it’s only the lines about attempted access each midnight 
 
- An ICMP ping or a web request? - If it’s a web request the first thing that comes to mind is do you have BitWarden? - Yes, I do. It is probably a web request - There was a post a few days ago about someone using it and it pulled a tonne of data. I wonder if it also does polls to check if the link is still valid. - Bitwarden uses the favicon from the first link in the password entry. 
 For my selfhosted web pages I use the public info page of the selfhosted page (e.g. openMediaVault) and set detection to [- none].
 This way it won’t match against the 3rd party page but I get the icon :)- BUUUT it should only poll if you activate the program/extension. 
 Don’t know why it should poll at midnight
- I do not have my Lemmy’s link in the Bitwarden 
 
 
 
- And when you ping that IP address back, what happens? - Can you trace it? - Maybe setup wireshark and record what happens at that time of night… - I will definitely do that, right now I can’t work with anything because the traffic gets stopped at Pangolin’s level, but I will turn off Pangolin’s auth for one night 
 





