Add note about postgres

README.md

@@ -1,6 +1,6 @@
 # Pleroma-Docker (Unofficial)
 
-[Pleroma](https://pleroma.social/) is a selfhosted social network that uses OStatus/ActivityPub.
+[Pleroma](https://pleroma.social/) is a selfhosted social network that uses ActivityPub.
 
 This repository dockerizes it for easier deployment.
 
@@ -17,8 +17,7 @@ This repository dockerizes it for easier deployment.
  * thermonuclear war, or you getting fired because your boss saw your NSFW posts.
  *
  * Please do some research if you have any concerns about the
- * included features or software ***before*** using it.
- *
+ * included features or software *before* using it.
  */
 ```
 
@@ -32,7 +31,7 @@ Take a look at [hosted/pleroma](/hosted/pleroma) if you get stuck or need some i
 Additionally it's known to run on (in no particular order):
 - social.interhop.org
 - social.technodruide.ca
-- toot.poto.cafe
+- is.badat.dev
 
 Does your instance use pleroma-docker?<br/>
 Let me know and I'll add you to this list.
@@ -85,6 +84,26 @@ You can run these tasks in your running pleroma server using `./pleroma.sh mix [
 For example: `./pleroma.sh mix pleroma.user new sn0w ...`<br/>
 If you need to fix bigger problems you can also spawn a shell with `./pleroma.sh enter`.
 
+### Postgres Upgrades
+
+Postgres upgrades are a slow process in docker (even more than usual) because we can't utilize `pg_upgrade` in any sensible way.<br/>
+If you ever wish to upgrade postgres to a new major release for some reason, here's a list of things you'll need to do.
+
+- Inform your users about the impending downtime
+    - Seriously this can take anywhere from a couple hours to a week depending on your instance
+- Make sure you have enough free disk space or some network drive to dump to, we can't do in-place upgrades
+- Stop pleroma (`docker-compose stop server`)
+- Dump the current database into an SQL file (`docker-compose exec db pg_dumpall -U pleroma > /my/sql/location/pleroma.sql`)
+- Remove the old containers (`docker-compose down`)
+- Modify the postgres version in `docker-compose.yml` to your desired release
+- Delete `data/db` or move it into some different place (might be handy if you want to abort/revert the migration)
+- Start the new postgres container (`docker-compose up -d db`)
+- Start the import (`docker-compose exec -T db psql -U pleroma < /my/sql/location/pleroma.sql`)
+- Wait for a possibly ridculously long time
+- Boot pleroma again (`docker-compose up -d`)
+- Wait for service to stabilize while federation catches up
+- Done!
+
 ### Customization
 
 Add your customizations (and their folder structure) to `custom.d/`.<br/>