feat: add build PR flow

.github/workflows/build-pr.yaml

@@ -0,0 +1,33 @@
+name: "Build Django image in PR"
+
+concurrency:
+  group: ${{ github.ref }}
+  cancel-in-progress: true
+
+on:
+  push:
+    branches:
+      - "*"
+  workflow_dispatch:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v3
+
+      - name: Set up Docker Buildx
+        uses: docker/setup-buildx-action@v2
+
+      - name: Build only
+        uses: docker/build-push-action@v4
+        id: build-image
+        env:
+          REGISTRY: ghcr.io/antvirf/railway_django_stack
+        with:
+          context: ./.
+          file: ./Dockerfile
+          push: false
+          tags: ${{env.REGISTRY}}:${{github.run_number}}
+          cache-from: type=gha
+          cache-to: type=gha,mode=max

README.md

@@ -56,3 +56,13 @@ This is a barebones Django-project with the following additions/updates:
     - [`django-celery-results`](https://github.com/celery/django-celery-results) for viewing results of Celery tasks in Django Admin
 - Uses [`python-decouple`](https://github.com/HBNetwork/python-decouple) to manage settings via environment varialbes
 - Installs and runs with [`gunicorn`](https://github.com/benoitc/gunicorn)
+
+## Variable configurations
+
+| Variable | Description | Used by |
+| -------- | ----------- | ------- |
+`POSTGRES_HOST` | This should be the private URL of the Postgres service | Django, Celery
+`POSTGRES_DB` | Sets the Postgres default database name | Django, Celery, Postgres
+`POSTGRES_USER` | Sets the Postgres username | Django, Celery, Postgres
+`POSTGRES_PASSWORD` | Sets the Postgres user's password | Django, Celery, Postgres
+`REDIS_URL` | Configures the private URl of the Redis service | Django, Celery |