Upgrade PostgreSQL database from version 16 to 18

.pre-commit-config.yaml

@@ -45,5 +45,10 @@ repos:
   - repo: meta
     hooks:
       - id: check-useless-excludes
+  - repo: https://github.com/adamchainz/django-upgrade
+    rev: 1.31.1
+    hooks:
+      - id: django-upgrade
+
 default_language_version:
   python: python3

backend/code_review_backend/issues/admin.py

@@ -7,6 +7,7 @@
 from code_review_backend.issues.models import Diff, Issue, Repository, Revision
 
 
+@admin.register(Repository)
 class RepositoryAdmin(admin.ModelAdmin):
     list_display = ("slug", "url")
 
@@ -23,6 +24,7 @@ class DiffInline(admin.TabularInline):
     )
 
 
+@admin.register(Revision)
 class RevisionAdmin(admin.ModelAdmin):
     list_display = (
         "id",
@@ -41,6 +43,7 @@ class RevisionAdmin(admin.ModelAdmin):
     inlines = (DiffInline,)
 
 
+@admin.register(Issue)
 class IssueAdmin(admin.ModelAdmin):
     list_filter = ("analyzer",)
     list_display = (
@@ -55,9 +58,5 @@ class IssueAdmin(admin.ModelAdmin):
     ordering = ("-created",)
 
 
-admin.site.register(Repository, RepositoryAdmin)
-admin.site.register(Revision, RevisionAdmin)
-admin.site.register(Issue, IssueAdmin)
-
 # Naming
 admin.site.site_header = "Mozilla Code Review Backend"

backend/requirements.txt

@@ -1,4 +1,4 @@
-Django==5.1.15
+Django==6.0.8
 django-cors-headers==4.9.0
 django-environ==0.14.0
 djangorestframework==3.17.1

docker-compose.yml

@@ -26,12 +26,12 @@ services:
 
   db:
     container_name: code-review-db
-    image: postgres:16-alpine
+    image: postgres:18-alpine
 
     ports:
       - 127.0.0.1:5432:5432
     volumes:
-      - pgdata:/var/lib/postgresql/data
+      - pgdata:/var/lib/postgresql
     environment:
       POSTGRES_USER: devuser
       POSTGRES_PASSWORD: devdata

docs/docker.md

@@ -32,3 +32,52 @@ You can download the backup from the Heroku datastore dedicated page.
 export PGPASSWORD=devdata
 pg_restore -h localhost --user devuser -d code_review_dev path/to/dump
 ```
+
+## Upgrade an existing PostgreSQL database
+
+The PostgreSQL data is stored through a Docker volume. To avoid any data loss, we advice to save a copy of the volume before following the below instructions. The volume is usually located at `/var/lib/docker/volumes/code-review_pgdata/`.
+
+We recommend performing the update using `pg_dump`, as it simplifies handling multiple major PostgreSQL updates.
+Make sure you ran all the latest migrations and checked out to the latest version before continuing.
+
+1. Back up the existing data using `pg_dump`
+
+```sh=
+docker run -d --rm --name=old-database \
+    -e POSTGRES_PASSWORD=devdata \
+    -e POSTGRES_USER=devuser \
+    -e POSTGRES_DB=code_review_dev \
+    -v code-review_pgdata:/var/lib/postgresql/data -p 127.0.0.1:5432:5432 postgres:<old_version>-alpine
+PGPASSWORD=devdata pg_dump -h localhost -p 5432 -U devuser -d code_review_dev > dump.sql
+```
+
+There should be no error and the size of `dump.sql` should be approximately the size of the volume.
+
+2. ⚠ Trash the previously used volume:
+
+```sh=
+docker kill old-database
+docker volume rm code-review_pgdata
+```
+
+You will need to kill all database access first. In case docker complains about a container using the volume, you may also have to delete the container first:
+
+```sh=
+docker rm <container_id>
+```
+
+3. You can then run the up-to-date PostgreSQL via `docker-compose.yml` and restore the data:
+
+```sh=
+docker compose up db -d
+docker exec code-review-db postgres -V # Should return the latest PostgreSQL version
+PGPASSWORD=devdata psql --user=devuser --host=localhost -d code_review_dev < dump.sql
+```
+
+4. Check the application runs as expected by starting a development server: all your data should be there.
+
+5. ⚠ Cleanup the local file used for the dump:
+
+```sh=
+rm dump.sql
+```