So you've got an Owncast server running, and it's part of the Fediverse, so your Mastodon friends can be notified when you start a stream. Neat!

If you want to switch hosting providers, or install from scratch, you'll want to make sure your followers continue to receive notifications. This could be easy, or a bit of a challenge. Either way, here's what to do!

The easy way - Copy over the database

The simple solution is to just copy over the data/ folder from your old server, onto the new one. This includes the previous database, and assets like logos, etc.

This will work if you're moving to the same (or a newer) version of Owncast.

If that doesn't work

In my case, I couldn't migrate over because I was moving to an older Owncast version, for complicated reasons.

So, I had to manually copy over just the Fediverse/ActivityPub data from the old instance.

To finish this, you'll need the sqlite3 client on both instances. On Debian, this is sudo apt install sqlite3.

Extract ActivityPub tables and configuration values

# On the old server
cd data
sqlite3 owncast.db ".dump ap_followers ap_outbox ap_accepted_activities datastore" > owncast-activitypub.sql

Copy the owncast-activitypub.sql file off your old server using whatever means you like, scp, etc.

Tweak import script

I had to make these changes to the sql file manually:

Remove table schema creation

By default the .dump operation includes CREATE TABLE lines. Remove them from the script so you're just left with INSERT statements.

Accomodate data differences

Since I was moving onto an older version of Owncast, the database had a different schema, so you'll have to tweak the INSERT statements to reflect the version you're moving to. i.e., we're performing a "backwards migration".

You can see which database version you're running with:

# On the new instance
sqlite3 owncast.db "select value from config"

Check whether any migrations have happened to the ap_* tables; you can view the Forward migrations file for details. In particular, I was moving down to version 3, and so I had to remove the request_object column from the ap_followers line:

-- Convert this:
INSERT INTO ap_followers VALUES('https://carhenge.club/users/mattdsteele','https://carhenge.club/users/mattdsteele/inbox','Matt Steele','mattdsteele@carhenge.club','https://s3-us-east-2.amazonaws.com/carhengeclub/accounts/avatars/000/022/282/original/238f5dcb7409495b.jpeg','https://carhenge.club/79be21a3-3c15-4174-9cc2-116440ccda04','2022-11-22 04:39:12','2022-11-22 04:39:12.733741659+00:00',NULL,X'somelongvalue');

-- Into this:
INSERT INTO ap_followers VALUES('https://carhenge.club/users/mattdsteele','https://carhenge.club/users/mattdsteele/inbox','Matt Steele','mattdsteele@carhenge.club','https://s3-us-east-2.amazonaws.com/carhengeclub/accounts/avatars/000/022/282/original/238f5dcb7409495b.jpeg','https://carhenge.club/79be21a3-3c15-4174-9cc2-116440ccda04','2022-11-22 04:39:12','2022-11-22 04:39:12.733741659+00:00',NULL);

Depending on the version you're migrating to/from, you may have to make additional changes, or none at all!

Extract config table values

Remove all the INSERT INTO datastore lines except for the following:

federation_enabled
federation_go_live_message
federation_username

These need to be the same on the new host, in order for clients to validate identity.

Import data into new instance

After making these changes, copy the owncast-activitypub.sql file onto the new host, place it in the data folder, and run:

# On the new server
cd data
sqlite3 owncast.db ".read owncast-activitypub.sql"

With that, you should be able to test creating a new stream, or compose a new post in the Admin header, and you're off to the races!