Put public port in .env

.env.example

@@ -0,0 +1,11 @@
+DJANGO_SECRET_KEY="django-secret-key"
+DEBUG=True
+PUBLIC_PORT=8000
+DJANGO_LOGLEVEL=info
+DJANGO_ALLOWED_HOSTS=localhost
+DATABASE_ENGINE=postgresql_psycopg2
+DATABASE_NAME=dockerdjango
+DATABASE_USERNAME=dbuser
+DATABASE_PASSWORD=dbpassword
+DATABASE_HOST=db
+DATABASE_PORT=5432

compose.yml

@@ -16,7 +16,7 @@ services:
    build: .
    container_name: django-docker
    ports:
-     - "8000:8000"
+     - "${PUBLIC_PORT}:8000"
    depends_on:
      - db
    environment: