Ability to perform a domain migration or switch

[QuadPiece]

In the past it's been asked if it's possible to change the domain of an instance, to which the reply has been no, since the fediverse would see users as being located on an entirely new server.

But since that question got asked, mastodon has added an environment variable by the name ALTERNATE_DOMAINS. It seems logical that by changing LOCAL_DOMAIN and leaving the previous domain in ALTERNATE_DOMAINS, one could in theory perform a domain migration. Effectively swapping the domain for all their users without them losing their followers.

However, reality is rarely this simple. If someone were to attempt this, would it work? And if it did, what effects would one expect to see across the fediverse? Would other servers update the entries in their database? Would they see duplicate accounts that post the exact same content?

I don't know how other fediverse participants would handle it, such as GNU Social or Pleroma. But if Mastodon has an ALTERNATE_DOMAINS variable to allow multiple handles, it makes sense that it should also have a system to prevent duplicate domains from getting recognized, same for GNU Social and others.

If it's not currently possible, implementing support for such a migration should be considered as long as it's viable.
If it currently is possible, it should be documented somewhere in tootsuite/documentation

---

• I searched or browsed the repo’s other issues to ensure this is not a duplicate. (Possible duplicate of Change instance's domain #1902, but nobody replied when I attempted to get it reopened)
• This bug happens on a tagged release and not on master (If you're a user, don't worry about this).

[RayChimera]

Any news about this? I want to migrate but it's too few information about the topic.

[tusooa]

Test:

1: Install a mastodon server with LOCAL_DOMAIN=test1.X WEB_DOMAIN=test2.X

2: In Pleroma, query and follow test@test1.X (it is shown as test@test2.X)

3: Change WEB_DOMAIN=test1.X and ALTERNATE_DOMAINS=test2.X , restart mastodon

4: 301 Redirect test2.X to test1.X, and make test1.X proxy to mastodon

5: Try to remote follow test@test2.X on Pleroma

Result:

a: In following list there are two accounts from test@test1.X and test@test2.X

b: Newer statuses from the user will only show on the profile page of test@test1.X

c: Searching in Pleroma for test@test1.X and test@test2.X will yield both users. Searching using https://test1.X/@test and https://test2.X/@test will also yield both users.

Conclusion:

Pleroma is not able to de-duplicate accounts on migrated servers.

[maswan]

Is this still as good as it gets? I have a server that I need to move to another domain within a few months.

[tusooa]

Is this still as good as it gets? I have a server that I need to move to another domain within a few months.

Correct. mastodon uses webfinger id as the canonical identifier for an account while pleroma uses ap id, a lot of other software also does. If you only care about federating with other mastodons, you can change WEB_DOMAIN as you wish, as long as LOCAL_DOMAIN is untouched. If you do care about other software, you may not change WEB_DOMAIN because it determines the ap id of the user.

[maswan]

Well, since the old domain is going away due to circumstances beyond our control, getting mastodon federation moved over is better than getting nothing moved over, I guess.

[tusooa]

Well, since the old domain is going away due to circumstances beyond our control, getting mastodon federation moved over is better than getting nothing moved over, I guess.

Then it is not the same thing any more. You need to have control on LOCAL_DOMAIN (for webfinger). If you will no longer own that domain, webfinger queries can't fetch your accounts.

[maswan]

So, what relevance does this has to the topic of this issue: changing domain for an instance? I thought the whole point of issuing 301s over a transition time was to get all peers that care to update to the new location.

[adrianmace]

I have a situation where I created an instance on mace.au and would like to move it to social.mace.au.

I would like to start the instance with WEB_DOMAIN=mace.au and LOCAL_DOMAIN=social.mace.au, then put a 301 redirect in for the webfinger. (Instructions per official docs for these two variables).

Would this be possible to do today, or does it need further thought / this feature request?

I would hope that remote servers would just follow the 301 since they’d initially be trying to connect on the original URL still, no?

[vgskye]

I don't think WEB_DOMAIN is really relevant in this; WEB_DOMAIN is just where the WebUI is served afaik and I don't think it's relevant for a LOCAL_DOMAIN change, only ALTERNATE_DOMAINS

[tusooa]

I don't think WEB_DOMAIN is really relevant in this; WEB_DOMAIN is just where the WebUI is served afaik and I don't think it's relevant for a LOCAL_DOMAIN change, only ALTERNATE_DOMAINS

It's used in AP ids, which is the canonical identifier in ActivityPub. You should never change ap ids.

[vgskye]

I don't think WEB_DOMAIN is really relevant in this; WEB_DOMAIN is just where the WebUI is served afaik and I don't think it's relevant for a LOCAL_DOMAIN change, only ALTERNATE_DOMAINS

It's used in AP ids, which is the canonical identifier in ActivityPub. You should never change ap ids.

ah, gotcha.