Refactor Docker networking and health checks in docker-compose.yml

src/go-postgres/.devcontainer/docker-compose.yml

@@ -1,5 +1,3 @@
-version: '3.8'
-
 volumes:
   postgres-data:
 
@@ -26,6 +24,16 @@ services:
   db:
     image: postgres:latest
     restart: unless-stopped
+
+    # Health check ensures PostgreSQL is ready before dependent services start
+    # This is critical for depends_on with condition: service_healthy to work properly
+    healthcheck:
+      test: [ "CMD-SHELL", "pg_isready -U postgres" ]
+      interval: 10s # Check every 10 seconds
+      timeout: 5s # Wait up to 5 seconds for response
+      retries: 5 # Retry 5 times before marking as unhealthy
+      start_period: 30s # Give PostgreSQL 30 seconds to start before health checks begin
+
     volumes:
       - postgres-data:/var/lib/postgresql
     env_file: