To help you better remember and understand the concepts and practices of Docker described in this chapter, try answering the following questions without going back to the chapter's contents. Let's get started:
- What are containers? What's the key difference between containers and virtual machines?
- What are the main features inside the Linux kernel to enable container technology? Please name at least two of them.
- What are the key concepts of the Docker workflow?
- What is a Dockerfile for? Which Docker command do you use to interact with it?
- What is the ENTRYPOINT instruction inside a Dockerfile?
- Which command do we use to list all Docker images?
- Which command do we use to form a Docker Swarm cluster?
- What is the key difference between Swarm classic and Swarm mode?
- Please explain the relationship between services and tasks.
- How can we create an NGINX service with five replicas?
- How can we scale down the number of the NGINX services to two?
- What is the minimum number of nodes required to form a Swarm cluster with the high-availability property? Why?
- What is the name for a network that is part of the routing mesh? How large is it?
- Which port numbers are used by a Swarm cluster? What are they for?
- What is the main benefit of network-scoped Gossip communication?