Docker Interview Questions and Answer Part – 26

What Docker Client command can be used to convert a Dockerfile into an Image?

• docker createimage
• docker buildimage
• docker build (Ans)
• docker create

Which of the following statements accurately describe a Docker volume?

• Persisted even after a container is deleted
• All of these (Ans)
• Can be shared and reused among containers
• Special type of directory in a container
• Are not affected by updates to images

Which option can we pass to the Docker daemon to make it assign the Docker bridge a specific IP range?

• –bip (Ans)
• –network
• –ip-range
• –cidr

Which Dockerfile Instruction is the preferred instruction for setting the main process to run inside a container?

• DEFAULT
• ENTRYPOINT (Ans)
• CMD
• RUN

Which command shows us detailed container info including the containers PID within the Docker Hosts process tree?

• docker config
• docker detail
• docker inspect (Ans)
• docker pid

When using the ENTRYPOINT Instruction in a Dockerfile, how are CMD Instructions treated?

• CMD Instructions are treated as arguments to the ENTRYPOINT Instruction (Ans)
• CMD Instructions override ENTRYPOINT Instructions
• ENTRYPOINT Instructions are ignored
• CMD Instructions are ignored

Which Dockerfile Instruction do we use to install packages to our new Image?

• FROM
• RUN (Ans)
• apt-get install
• CMD

What is the name of the primary virtual Ethernet NIC inside of each Docker container?

• veth0
• eth1
• veth1
• eth0 (Ans)

Which Docker command lets us attach to a running container?

• docker ssh
• docker login
• docker telnet
• docker attach (Ans)

Which of the following docker run commands will start a Container based on an Ubuntu 14.04 Base Image?

• docker run Ubuntu:14.04 ….
• docker run ubuntu -v 14.04 …..
• docker run ubuntu:14.04 …. (Ans)
• docker run ubuntu –version=14.04 ….

Which of the following commands will install the Docker engine on an Ubuntu server?

• cf install docker.io
• rkt install docker
• yum install docker
• apt-get install docker.io (Ans)

Virtual Machines are a form of what type of virtualization?

• Container
• Hypervisor (Ans)
• VLAN
• Mainframe

How do recipient containers learn about the networking config of source containers they are linked to?

• By querying the Docker daemon
• Via a sub-space secure channel to the source container
• Environment variables + entries in the /etc/hosts file (Ans)
• The /link file in the root filesystem of the container

Which of the following commands will show version information for the various installed Docker components?

• docker version (Ans)
• apt-get update
• docker detail
• rkt version

Which Docker command builds a new image from a Dockerfile in the current directory?

• docker build
• docker build-image .
• docker image .
• docker build . (Ans)

What does pressing Control+P+Q inside of a container do?

• Issues a print-screen of the current contents of the terminal window
• Detaches the Docker Hosts terminal from the container (Ans)
• Kills the container
• Generates a stack trace of the container

Which Docker command shows running Docker Containers?

• docker ps (Ans)
• docker list containers
• docker show containers
• rkt ps

Which of the following is a major advantage of Containers over Virtual Machines?

• Containers are more lightweight than Virtual Machines. (Ans)
• Containers are encrypted by default.
• A single Container can host more apps than a Virtual Machine.
• Containers are cross-platform.

Which of the following is an advantage of Linking Containers when compared to exposing ports?

• Linking containers is more efficient on memory.
• Linking containers allow more active network connections.
• Linking containers allows for faster container startup times.
• Linking containers is considered more secure. (Ans)

What is the correct syntax to mount the /project/data directory from the Docker host into a directory called /data in a container?

• docker run -v /data:/project/data
• docker run -volumes-from /project/data:/data
• docker run -v /project/data:/data (Ans)
• docker run -volumes-from /data:/project/data

Rajesh Kumar

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