20 October 2020

#Docker

#Docker

Key Concepts


Topic Sub-Topic(s) Basic Intermediate Advanced Expert
Introduction to Docker What is Docker, Containers vs VMs, Benefits of Docker ✅
Docker Architecture Docker Daemon, Docker Client, Docker Registry, Docker Objects ✅ ✅
Installation & Setup Installing Docker on Linux/Windows/Mac, Post-installation steps ✅ ✅
Docker Images Pull, Build, Tag, Push, Save & Load Images, Layers, Best Practices ✅ ✅ ✅
Docker Containers Run, Start, Stop, Exec, Logs, Inspect, Lifecycle ✅ ✅ ✅
Dockerfile Syntax, Instructions (FROM, RUN, COPY, CMD, ENTRYPOINT, ENV, EXPOSE), Multi-stage builds ✅ ✅ ✅ ✅
Docker Volumes Bind Mounts vs Volumes, Named Volumes, Data Persistence ✅ ✅ ✅
Networking in Docker Bridge, Host, None, Overlay, Macvlan, Network Drivers ✅ ✅ ✅ ✅
Docker Compose docker-compose.yml, Multi-container apps, Scaling, Environment variables ✅ ✅ ✅ ✅
Docker Registry Docker Hub, Private Registry, Authentication, Security ✅ ✅ ✅
Docker Security Least Privilege, Seccomp, Capabilities, User Namespaces, Image Scanning ✅ ✅ ✅
Docker Orchestration Docker Swarm basics, Service scaling, Rolling updates ✅ ✅ ✅
Docker & Kubernetes Running Docker containers in Kubernetes, CRI-O, containerd ✅ ✅ ✅
Monitoring & Logging Docker Logs, Metrics, Prometheus/Grafana, ELK Stack integration ✅ ✅ ✅
Troubleshooting Debugging containers, Common issues, Resource limits, Networking problems ✅ ✅ ✅
Performance Optimization Image optimization, Layer caching, Container resource constraints ✅ ✅
CI/CD with Docker Docker in Jenkins, GitLab CI, GitHub Actions, Automated pipelines ✅ ✅
Enterprise Docker Docker Enterprise Edition, Role-based Access, Cluster Management ✅
Docker Alternatives Podman, Buildah, containerd, CRI-O ✅ ✅
Real-world Use Cases Microservices, Legacy app modernization, Cloud-native deployments ✅ ✅ ✅

Interview question

1. Docker Basics

  1. What is Docker, and why is it used?
  2. How is Docker different from Virtual Machines?
  3. What are the main benefits of containerization?
  4. What are the key components of Docker architecture?
  5. What is Docker Daemon?
  6. What is the role of Docker CLI?
  7. What is Docker Hub?
  8. Explain Docker client-server architecture.
  9. What are Docker objects?
  10. What is a container vs. an image?
  11. What problems does Docker solve in DevOps?
  12. What is Docker Desktop?
  13. What is the lifecycle of a container?
  14. What are common Docker commands?
  15. What is the role of namespaces in Docker?
  16. What are control groups (cgroups)?
  17. What is a Docker context?
  18. How do you check the Docker version installed?
  19. What are common real-world use cases for Docker?
  20. Why is Docker popular in microservices architecture?

2. Docker Architecture

  1. Explain Docker?s layered architecture.
  2. What is the Docker Engine?
  3. What is containerd?
  4. What is runc in Docker?
  5. How do storage drivers work in Docker?
  6. What is the role of Union File System?
  7. Explain how container isolation works.
  8. What are different storage drivers supported by Docker?
  9. Explain overlay2 storage driver.
  10. What are Docker plugins?
  11. What is the purpose of REST API in Docker?
  12. How does Docker architecture differ on Windows vs Linux?
  13. What is the role of registry in Docker architecture?
  14. What is the difference between image layers and container layers?
  15. How does Docker handle networking internally?
  16. What is the architecture of Docker Swarm?
  17. How does Docker manage persistent data?
  18. How does Docker achieve portability across platforms?
  19. What are the limitations of Docker architecture?
  20. How do you troubleshoot Docker Daemon issues?

3. Docker Images

  1. What is a Docker image?
  2. Difference between image and container?
  3. How do you build an image?
  4. What is a base image?
  5. Difference between scratch and alpine base images?
  6. How do you optimize Docker image size?
  7. What is a multi-stage build?
  8. What is an image layer?
  9. How does caching work in Docker builds?
  10. How do you share Docker images?
  11. How do you push an image to Docker Hub?
  12. How do you pull an image from a registry?
  13. What is the difference between docker save and docker export?
  14. How do you inspect an image?
  15. How do you tag an image?
  16. What is the purpose of .dockerignore file?
  17. What are best practices for image naming?
  18. How do you remove unused images?
  19. What is the difference between dangling and intermediate images?
  20. How do you sign and verify images?

4. Docker Containers

  1. What is a Docker container?
  2. How do you run a container?
  3. How do you run a container in detached mode?
  4. Difference between docker run and docker start?
  5. How do you check running containers?
  6. How do you stop and remove containers?
  7. How do you restart a stopped container?
  8. What is an ephemeral container?
  9. How do you copy files into a running container?
  10. How do you commit a container into an image?
  11. What is the difference between volumes and bind mounts?
  12. How do you exec into a running container?
  13. How do you check container logs?
  14. How do you check resource usage of containers?
  15. What is the difference between interactive and non-interactive containers?
  16. How do you share data between two containers?
  17. How do you restart all containers with a single command?
  18. What is the difference between container pause and stop?
  19. How do you enforce resource limits on a container?
  20. What is container lifecycle management?

5. Docker Networking

  1. What types of networks exist in Docker?
  2. What is the default network type?
  3. Explain bridge network in Docker.
  4. What is host network?
  5. What is none network?
  6. What is an overlay network?
  7. How do you list all Docker networks?
  8. How do you connect a container to multiple networks?
  9. How do containers communicate inside a bridge network?
  10. What is port mapping in Docker?
  11. Difference between -p and -P?
  12. How do you assign a static IP to a container?
  13. How do you inspect a Docker network?
  14. How do you create a custom network?
  15. What is the purpose of service discovery in networks?
  16. How does Docker handle DNS resolution?
  17. How do you connect containers across hosts?
  18. How do you troubleshoot network connectivity in Docker?
  19. How do you remove unused networks?
  20. What are limitations of Docker networking?

6. Docker Volumes & Storage

  1. What is a Docker volume?
  2. Why use volumes instead of bind mounts?
  3. How do you create and attach a volume?
  4. How do you share a volume between containers?
  5. How do you inspect a volume?
  6. How do you back up a Docker volume?
  7. How do you remove a volume?
  8. What is a tmpfs mount?
  9. How do you clean up unused volumes?
  10. Difference between local and remote volumes?
  11. What is a volume driver?
  12. How do you use NFS volumes in Docker?
  13. How do you encrypt Docker volumes?
  14. How do you monitor disk usage by volumes?
  15. How do you migrate Docker volumes?
  16. What is the default volume location?
  17. How do you restrict volume access?
  18. What are best practices for managing volumes?
  19. What is the difference between persistent and ephemeral storage?
  20. How do you troubleshoot volume mounting issues?

7. Docker Compose

  1. What is Docker Compose?
  2. What is the purpose of docker-compose.yml?
  3. How do you define multiple services in Compose?
  4. How do you pass environment variables to Compose?
  5. What is the difference between docker run and Compose?
  6. How do you scale services in Compose?
  7. What is the difference between up and start?
  8. How do you override Compose files?
  9. How do you build images with Compose?
  10. How do you restart services in Compose?
  11. How do you define networks in Compose?
  12. How do you share volumes in Compose?
  13. How do you debug services in Compose?
  14. What is the default project name in Compose?
  15. How do you use profiles in Compose?
  16. How do you extend Compose configurations?
  17. How do you stop all services in Compose?
  18. How do you run one-off tasks with Compose?
  19. How do you deploy Compose in production?
  20. What are limitations of Docker Compose?

8. Docker Swarm & Orchestration

  1. What is Docker Swarm?
  2. How do you initialize a Swarm cluster?
  3. What is the role of manager and worker nodes?
  4. How do you deploy services in Swarm?
  5. How do you scale services in Swarm?
  6. How do you update a service in Swarm?
  7. What is rolling update in Swarm?
  8. How do you remove nodes from Swarm?
  9. What is service discovery in Swarm?
  10. How do you create secrets in Swarm?
  11. How do you use configs in Swarm?
  12. How do you achieve high availability in Swarm?
  13. How do you monitor Swarm nodes?
  14. What is the difference between Swarm and Kubernetes?
  15. How do you troubleshoot Swarm cluster issues?
  16. How do you restart Swarm services?
  17. What is ingress routing mesh?
  18. How do you backup a Swarm cluster?
  19. How do you secure Swarm communications?
  20. What are limitations of Docker Swarm?

9. Docker Security

  1. How do you secure Docker images?
  2. What is Docker Content Trust (DCT)?
  3. How do you scan Docker images for vulnerabilities?
  4. What is the role of namespaces in security?
  5. What is seccomp in Docker?
  6. How does AppArmor work with Docker?
  7. How does SELinux work with Docker?
  8. How do you restrict container privileges?
  9. What is rootless mode in Docker?
  10. How do you run a container with read-only filesystem?
  11. How do you prevent container breakout?
  12. How do you limit container resources?
  13. What are secrets in Docker?
  14. How do you manage credentials securely?
  15. How do you secure Docker API?
  16. How do you secure Docker socket?
  17. What is the principle of least privilege in Docker?
  18. How do you enforce user namespaces?
  19. How do you apply RBAC in Docker Enterprise?
  20. What are common Docker security best practices?

10. Docker in CI/CD & Best Practices

  1. How is Docker used in CI/CD pipelines?
  2. How do you integrate Docker with Jenkins?
  3. How do you use Docker with GitLab CI/CD?
  4. How do you automate image builds?
  5. How do you run automated tests in Docker?
  6. How do you manage environment-specific Dockerfiles?
  7. What are best practices for writing Dockerfiles?
  8. What are best practices for image tagging?
  9. What are best practices for container logging?
  10. How do you monitor Docker containers?
  11. How do you integrate Docker with Prometheus?
  12. How do you use ELK stack with Docker?
  13. How do you debug failed container builds?
  14. How do you optimize Docker for production use?
  15. How do you manage Docker at scale in enterprises?
  16. What are best practices for networking in Docker?
  17. How do you handle secrets in CI/CD pipelines with Docker?
  18. How do you ensure reproducibility in Docker builds?
  19. What are performance optimization techniques in Docker?
  20. What are common mistakes to avoid when using Docker in production?

Related Topics


   Docker_Commands   
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