fix: update environment variable handling in Docker Compose files and improve contributing documentation

.env.example

@@ -0,0 +1,12 @@
+# Host-side port for the API container (container port remains 3000)
+API_HOST_PORT=3001
+
+DATABASE_URL="postgresql://user:password@localhost:5432/nest_db"
+JWT_SECRET="change_me_to_a_long_random_string"
+PORT=3000
+
+ADMIN_USERNAME="admin"
+ADMIN_EMAIL="admin@example.com"
+ADMIN_PASSWORD="change_me"
+FRONT_ORIGIN="http://localhost:5173"
+INTRA_ORIGIN="http://localhost:5174"

CONTRIBUTING.md

@@ -49,7 +49,7 @@ npm install
 
 ### 3. Set Up Environment
 
-Create `.env` files based on the examples in each project. See the main [README.md](./README.md) for required environment variables.
+Create a root `.env` file from `.env.example` (`cp .env.example .env`) and adjust values as needed. See the main [README.md](./README.md) for required environment variables.
 
 ### 4. Create a Branch
 

README.md

@@ -23,9 +23,11 @@ nest-intra/      # Staff-only internal portal (React + Vite)
 ### 1. Backend Setup
 
 ```bash
-cd nest-backend
+# from repository root
 cp .env.example .env
-# Edit .env with your database credentials
+# Edit .env with your credentials
+
+cd nest-backend
 npm install
 npm run db:push        # Initialize database schema
 npm run db:seed        # Populate with sample data
@@ -35,6 +37,7 @@ npm run dev            # Start dev server (http://localhost:3000)
 #### Backend Environment Variables
 
 ```env
+API_HOST_PORT=3001
 DATABASE_URL="postgresql://user:password@localhost:5432/nest_db"
 JWT_SECRET="your-secret-key"
 PORT=3000

docker-compose.prod.yml

@@ -18,7 +18,7 @@ services:
     image: git.crowmate.fr/crowmate/nest-api:latest
     restart: unless-stopped
     ports:
-      - "3000:3000"
+      - "${API_HOST_PORT:-3001}:3000"
     environment:
       DATABASE_URL: postgresql://nest_user:nest_password@db:5432/nest_db
     depends_on:

docker-compose.yml

@@ -18,9 +18,9 @@ services:
     build: ./nest-backend
     restart: unless-stopped
     ports:
-      - "3000:3000"
+      - "${API_HOST_PORT:-3001}:3000"
     env_file:
-      - ./nest-backend/.env
+      - ./.env
     environment:
       DATABASE_URL: postgresql://nest_user:nest_password@db:5432/nest_db
     depends_on:

nest-backend/docker-compose.yml

@@ -18,7 +18,9 @@ services:
     build: .
     restart: unless-stopped
     ports:
-      - "3000:3000"
+      - "${API_HOST_PORT:-3001}:3000"
+    env_file:
+      - ../.env
     environment:
       DATABASE_URL: postgresql://nest_user:nest_password@db:5432/nest_db
       JWT_SECRET: ${JWT_SECRET:-change_me_in_production}