Docker and VPC Quiz

What is Docker primarily used for?

• Virtualizing operating systems

• Creating and managing containers

• Developing frontend applications

• Running only database applications

Answer explanation

Docker is primarily used for creating and managing containers, which allow developers to package applications and their dependencies in a lightweight, portable format. This is essential for consistent deployment across environments.

Which of the following is not an advantage of Docker?

• Lightweight and portable

• Faster startup than VMs

• Securely isolates applications

• Requires a different OS for each container

Answer explanation

The correct choice, 'Requires a different OS for each container', is not an advantage of Docker. Unlike virtual machines, Docker containers share the host OS, making them lightweight and portable.

Which of the following is used to create and manage containers in Docker?

• Docker Engine

• Docker Swarm

• Docker Image

• Kubernetes

Answer explanation

Docker Engine is the core component that creates and manages containers in Docker. It provides the necessary tools and APIs to build, run, and manage containerized applications, making it the correct choice.

What is the primary purpose of a Dockerfile?

• To define the configuration of a virtual machine

• To automate the creation of Docker images

• To deploy applications to Kubernetes

• To run Docker containers in production

Answer explanation

The primary purpose of a Dockerfile is to automate the creation of Docker images. It contains instructions that specify how to build an image, making it easier to manage and deploy applications consistently.

Which keyword in a Dockerfile is used to specify the base image?

• START

• FROM

• BASE

• IMAGE

Answer explanation

The correct keyword to specify the base image in a Dockerfile is 'FROM'. This instruction sets the starting point for the image being built, allowing you to build upon an existing image.

What does the CMD instruction in a Dockerfile do?

• Specifies the default command to run inside the container

• Copies files into the container

• Builds the Docker image

• Exposes ports for networking

Answer explanation

The CMD instruction in a Dockerfile specifies the default command that will run when a container is started from the image. This allows users to define what should happen when the container is executed.

What is the difference between CMD and ENTRYPOINT in a Dockerfile?

• CMD overrides the base image, but ENTRYPOINT does not

• CMD sets a default command, while ENTRYPOINT makes the command non-overridable

• CMD is used for networking, while ENTRYPOINT is for security

• CMD is used in build time, and ENTRYPOINT is for runtime

Answer explanation

CMD sets a default command that can be overridden, while ENTRYPOINT defines a command that is always executed and cannot be easily overridden. This distinction is crucial for controlling container behavior.

Which instruction is used to copy files from the host machine to the container?

• ADD

• COPY

• MOVE

• IMPORT

Answer explanation

The correct instruction to copy files from the host machine to the container is 'COPY'. While 'ADD' can also copy files, 'COPY' is the preferred and more straightforward command for this specific task.

Which of the following is NOT a Docker network driver?

• Bridge

• Overlay

• VirtualBox

• None

Answer explanation

VirtualBox is not a Docker network driver; it is a virtualization software. The correct Docker network drivers are Bridge and Overlay, which are used for container networking.

What is a Virtual Private Cloud (VPC)?

• A private cloud server

• A logically isolated network in the cloud

• A database hosting service

• A security tool for cloud computing

Answer explanation

A Virtual Private Cloud (VPC) is a logically isolated network in the cloud, allowing users to create a private environment within a public cloud infrastructure, enhancing security and control over resources.