Docker & Containerization
Dockerfile for Node.js/NestJS, docker-compose (Node + DB + Redis), multi-stage builds, image optimization, .dockerignore, volumes, networks, container orchestration basics
1What is Docker?
What is Docker?
回答
Docker is a containerization platform that packages an application and its dependencies into an isolated container. Unlike virtual machines that virtualize hardware, Docker shares the host OS kernel, making it lightweight and fast. Using Docker ensures the application runs identically in development, staging, and production.
2What is the main difference between a Docker container and a virtual machine?
What is the main difference between a Docker container and a virtual machine?
回答
A Docker container shares the host OS kernel and virtualizes only the user space, making it very lightweight (few MB) and starts in seconds. A VM virtualizes complete hardware and includes a full OS (several GB), starting in minutes. Containers are therefore more efficient for microservices and CI/CD.
3What is the role of the Dockerfile?
What is the role of the Dockerfile?
回答
The Dockerfile is a text file containing instructions to build a Docker image. Each instruction (FROM, COPY, RUN, CMD) creates a layer in the image. It defines the runtime environment, dependencies, and startup command. A well-optimized Dockerfile uses layer caching and multi-stage builds to reduce final image size.
Which Dockerfile instruction defines the base image?
What is the difference between CMD and ENTRYPOINT in a Dockerfile?
+22 面接問題