Keep MongoDB off the Internet and its password out of git

MongoDB was published on 0.0.0.0:27017 with the default "example" root
password. It now listens on 127.0.0.1 only (the apps use the Docker
network), and the root password comes from MONGO_PASSWORD in a
git-ignored .env file.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

docker-compose.yml

@@ -5,10 +5,12 @@ services:
     image: mongo:latest
     container_name: mongodb
     ports:
-      - "27017:27017"
+      # Seulement depuis la machine elle-même : les applications passent par le réseau Docker
+      - "127.0.0.1:27017:27017"
     environment:
       MONGO_INITDB_ROOT_USERNAME: root
-      MONGO_INITDB_ROOT_PASSWORD: example
+      # Mot de passe dans .env (MONGO_PASSWORD), hors du dépôt git
+      MONGO_INITDB_ROOT_PASSWORD: ${MONGO_PASSWORD:?MONGO_PASSWORD manquant dans .env}
     volumes:
       - mongodb_data:/data/db
     networks:
@@ -20,7 +22,7 @@ services:
     depends_on:
       - mongodb
     environment:
-      - MONGO_URI=mongodb://root:example@mongodb:27017/?authSource=admin
+      - MONGO_URI=mongodb://root:${MONGO_PASSWORD:?MONGO_PASSWORD manquant dans .env}@mongodb:27017/?authSource=admin
     networks:
       - app-network
     volumes: