make that php, mariadb and backup containers use the same env variables about database

docker-compose.yml

@@ -3,8 +3,8 @@ services:
     image: mariadb:latest
     container_name: app-mariadb
     environment:
-      - MYSQL_ROOT_PASSWORD=${MYSQL_ROOT_PASSWORD}
-      - MYSQL_DATABASE=${MYSQL_DATABASE}
+      - DB_ROOT_PASSWORD=${DB_ROOT_PASSWORD}
+      - DB_DATABASE=${DB_DATABASE}
     ports:
       - "3306:3306"
     volumes:
@@ -30,6 +30,12 @@ services:
       - BACKEND_GIT_REPO=${BACKEND_GIT_REPO}
       - BACKEND_GIT_BRANCH=${BACKEND_GIT_BRANCH}
       - DEV=${DEV}
+      - DB_CONNECTION=${DB_CONNECTION}
+      - DB_HOST=${DB_HOST}
+      - DB_PORT=${DB_PORT}
+      - DB_DATABASE=${DB_DATABASE}
+      - DB_USERNAME=${DB_USERNAME}
+      - DB_PASSWORD=${DB_PASSWORD}
     depends_on:
       - mariadb
       - typesense
@@ -96,9 +102,9 @@ services:
       dockerfile: Dockerfile
     container_name: app-backup
     environment:
-      - MYSQL_PASSWORD=${MYSQL_PASSWORD}
-      - MYSQL_DATABASE=${MYSQL_DATABASE}
-      - MYSQL_USER=${MYSQL_USER}
+      - DB_PASSWORD=${DB_PASSWORD}
+      - DB_DATABASE=${DB_DATABASE}
+      - DB_USERNAME=${DB_USERNAME}
     volumes:
       - ./backups:/backups
     restart: unless-stopped