feat: dockerize application

docker-compose.yml

@@ -10,4 +10,18 @@ services:
       test: ["CMD-SHELL", "pg_isready -U postgres"]
       interval: 5s
       timeout: 5s
-      retries: 5
+      retries: 5
+  
+  pg-instance-handler:
+    build:
+      context: .
+      dockerfile: Dockerfile
+    depends_on:
+      postgres:
+        condition: service_healthy
+    environment:
+      DATABASE_URL: postgres://postgres:postgres@postgres:5432/postgres
+    ports:
+      - "8080:8080"
+    volumes:
+      - ./database.txt:/database.txt:ro