Upgrading from postgres 15 -> 16-alpine. (#4426)

- Includes an upgrade script.
- Fixes #4406

.woodpecker.yml

@@ -257,7 +257,7 @@ steps:
 
 services:
   database:
-    image: postgres:15.2-alpine
+    image: postgres:16-alpine
     environment:
       POSTGRES_USER: lemmy
       POSTGRES_PASSWORD: password

docker/docker-compose.yml

@@ -99,7 +99,7 @@ services:
     logging: *default-logging
 
   postgres:
-    image: postgres:15-alpine
+    image: postgres:16-alpine
     # this needs to match the database host in lemmy.hson
     # Tune your settings via
     # https://pgtune.leopard.in.ua/#/

docker/federation/docker-compose.yml

@@ -20,7 +20,7 @@ x-lemmy-default: &lemmy-default
   restart: always
 
 x-postgres-default: &postgres-default
-  image: postgres:15-alpine
+  image: postgres:16-alpine
   environment:
     - POSTGRES_USER=lemmy
     - POSTGRES_PASSWORD=password

scripts/postgres_15_to_16_upgrade.sh

@@ -0,0 +1,42 @@
+#!/bin/sh
+set -e
+
+echo "Do not stop in the middle of this upgrade, wait until you see the message: Upgrade complete."
+
+echo "Stopping lemmy and all services..."
+sudo docker-compose stop
+
+echo "Make sure postgres is started..."
+sudo docker-compose up -d postgres
+echo "Waiting..."
+sleep 20s
+
+echo "Exporting the Database to 15_16.dump.sql ..."
+sudo docker-compose exec -T postgres pg_dumpall -c -U lemmy > 15_16_dump.sql
+echo "Done."
+
+echo "Stopping postgres..."
+sudo docker-compose stop postgres
+echo "Waiting..."
+sleep 20s
+
+echo "Removing the old postgres folder"
+sudo rm -rf volumes/postgres
+
+echo "Updating docker-compose to use postgres version 16."
+sed -i "s/image: postgres:.*/image: postgres:16-alpine/" ./docker-compose.yml
+
+echo "Starting up new postgres..."
+sudo docker-compose up -d postgres
+echo "Waiting..."
+sleep 20s
+
+echo "Importing the database...."
+cat 15_16_dump.sql | sudo docker-compose exec -T postgres psql -U lemmy
+echo "Done."
+
+echo "Starting up lemmy..."
+sudo docker-compose up -d
+
+echo "A copy of your old database is at 15_16.dump.sql . You can delete this file if the upgrade went smoothly."
+echo "Upgrade complete."