DOCKER

Multi-stage builds use separate builder and runtime stages to exclude build dependencies from the final image. Define multiple FROM statements in your Dockerfile, copy only compiled artifacts to the runtime stage, and Docker discards intermediate layers, significantly reducing final image size for production deployments.

Yes, Cloud Run accepts Docker container images. Build your Next.js app in a Dockerfile, push the image to Container Registry, then deploy via Cloud Run console or CLI. Cloud Run automatically handles scaling and networking for your containerized Next.js application.

Docker Compose orchestrates multiple containers for development. Define services, volumes, networks, and environment variables in a docker-compose.yml file, then run `docker-compose up` to start all containers. This approach mirrors production architecture locally and simplifies multi-service workflows.

Pass environment variables via .env files, docker-compose environment sections, or runtime flags with -e. Store sensitive values securely outside your Dockerfile, reference them in docker-compose or deployment tools, and avoid hardcoding secrets in image layers.

Use `docker logs` to inspect container output, `docker exec` to run commands inside running containers, and configure health checks in your Dockerfile or docker-compose.yml. Map ports to access the app locally and enable verbose logging to troubleshoot runtime issues.

Docker Compose is optional for single containers but valuable for consistent local development. For simple deployments, Docker alone suffices; use Compose when you need multiple services, volumes, networking, or want standardized development and production configurations.