chore: .env file to wire intra-docker association

.env.example

+######################################################
+DB_NAME=meanspec
+DB_USER=meanspec
+DB_PASSWORD=foopassword123
+
+
+######################################################
+# DO NOT MODITY IF YOU DON'T KNOW WHAT YOU ARE DOING #
+######################################################
+DB_HOST=postgres
+DB_PORT=5432
+
+# API listen port
+PORT=8000

.gitignore

 /database
 /redis/data
+
+/.env*
+!/.env.example

docker-compose.yml

@@ -8,6 +8,7 @@ services:
       LC_ALL: en_US.utf-8
     ports:
       - 8000:8000
+    env_file: .env
 
   postgres:
     image: docker.io/library/postgres:17-alpine
@@ -21,13 +22,14 @@ services:
     volumes:
       - ./database:/var/lib/postgresql/data
       - ./init/sql:/docker-entrypoint-initdb.d/
+    env_file: .env
     environment:
       TZ: Asia/Seoul
       LANG: en_US.utf-8
       LC_ALL: en_US.utf-8
-      POSTGRES_PASSWORD: foopassword123
-      POSTGRES_USER: meanspec
-      POSTGRES_DB: meanspec
+      POSTGRES_PASSWORD: ${DB_PASSWORD:-foopassword123}
+      POSTGRES_USER: ${DB_USER:-meanspec}
+      POSTGRES_DB: ${DB_NAME:-meanspec}
 
   redis:
     image: redis:7.4.1-alpine