I discovered yesterday evening that Lemmy.ml is blocking all inbound ActivityPub requests from /kbin instances. Specifically, a 403 ‘access denied’ is returned when the user agent contains “kbinBot” anywhere in the string. This has been causing a cascade of failures with federation for many server owners, flooding the message queue with transport errors.
This doesn’t appear to be a mistake; it has been done very deliberately, only on Lemmy.ml. Lemmy.world and other large instances do not exhibit the same behavior. It also isn’t a side effect of the bug introduced in Lemmy 0.18. You can observe by sending the following in a terminal
> curl -I --user-agent "kbinBot v0.1" https://lemmy.world/u/test
HTTP/2 200
[...]
> curl -I --user-agent "kbinBot v0.1" https://lemmy.ml/u/test
HTTP/2 403
[...]
> curl -I --user-agent "notKbinBot v0.1" https://lemmy.ml/u/test
HTTP/2 403
[...]
> curl -I --user-agent "placeholder-user-agent" https://lemmy.ml/u/test
HTTP/2 200
[...]
Additional evidence of this not being a Lemmy 0.18 bug:
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This occurs when making web requests to any location on the Lemmy.ml webserver, not just ActivityPub endpoints.
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Go to https://fedidb.org/software/lemmy and pick an instance running 0.18.0. Perform the above commands, replacing the URL for Lemmy.ml with that particular instance’s address.
If this continues, my instance may need to defederate from Lemmy.ml. This is especially problematic because Lemmy.ml continues to federate information outbound to other kbin instances while refusing to allow inbound communication from them.
Spoofing the user agent is less than ideal, and doesn’t respect Lemmy.ml’s potential wish to not be contacted by /kbin instances. I don’t post this to create division between communities, but I do hope that I can draw awareness to what’s going on here. Defederating /kbin instances entirely would even be better than arbitrarily denying access one-way. This said, we should all attempt to maintain a good-faith interpretation until otherwise indicated by the Lemmy developers. It’s possibel that this is a firewall misconfiguration or some other webserver-related bug.
Relevant comment from me (#354 - [BUG] Critical errors/failed messages during messenger:consume)
Edits:
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Yes, people have already tried reaching out to the Lemmy instance admins in their Matrix room with no answer.
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Someone has posed a question on Lemmy.ml about the block here: https://lemmy.ml/post/1563840
Man, I just realized how much I love kbin. I was on Lemmy arguing with people against defederation and something just felt off about it. It was like that rabid leftist part of Reddit that refused to see outside of their bubble. Kbin has a really moderate atmosphere and I’m happy to be here. I feel like people are allowed to have proper discourse here.
The two have roughly equal daily users, right? I have an account on both but kbin seems like it has generally less app development. Are there kbin apps I don’t know about yet?
Interesting, this is technically not defederation, as far as I understand it. Although effectively it seems at least similar.
One implication of the difference is that it is less transpartent. On https://lemmy.ml/instances, ‘kbin’ only shows up on the left side; federated.
I’m hoping we will get some explanation why these decisions were made, and why not as a defederation.
Could it be a problem due to the newest Lemmy software upgrade?
For what I read it’s a complete mess.
It denies access from non-en-us browsers, for example.
It wouldn’t surprise me if it messed with federation too.
But, they’re the devs. They did this mess. Why would they present a software upgrade that clearly had a lot of issues is beyond me…
While underhanded, it’s better than weirdo shit like worming their way into kbin instances and pulling coups on the mods, which is what online reds used to do to various left-leaning political subreddits, FB pages, etc. Better to keep the tanks in the depot.
I’m appalled that everyone in the comments is already jumping to conclusions without waiting for a statement by the lemmy.ml admins.
Yes, I know what’s up with the Lemmy devs, but that doesn’t imply anything here.
Well, it’s been more than a hot minute. How long are folks supposed to wait? There’s ultimately only two feasible scenarios here, given the details we have at hand.
Seriously. So much tutting and moralizing when nothing has actually been confirmed yet.
Uhh, I have a question for you since we’re another both users from lemmy.world
Can you open the post in a private tab and check if our comments in this post are visible from kbin?