Docker

Question 1

A container is a runtime instance of an i_._.

Answer 1

A container is a runtime instance of an image

Question 2

A c________ is a runtime instance of an image

Answer 2

A container is a runtime instance of an image

Question 3

C________s package software into standardized units

Answer 3

Containers package software into standardized units

Question 4

H________s are software that manages physical resources on a server

Answer 4

Hypervisors are software that manages physical resources on a server

Question 5

The major benefit of containers is that you can ship and run applications everywhere because containers b________ everything that the application needs to run.

Answer 5

The major benefit of containers is that you can ship and run applications everywhere because containers bundle everything that the application needs to run.

Question 6

The docker d_____ is a process running in the background that is responsible for managing containers, images, networks, and volumes.

Answer 6

The docker daemon is a process running in the background that is responsible for managing containers, images, networks, and volumes.

Question 7

The docker clients (docker desktop or docker CLI) communicate with the docker d_____ to perform actions on or with containers.

Answer 7

The docker clients (docker desktop or docker CLI) communicate with the docker daemon to perform actions on or with containers.

Question 8

Docker images can be stored in r________s in the cloud via DockerHub

Answer 8

Docker images can be stored in registries in the cloud via DockerHub

Question 9

When a container is launched, it gets one final layer called the w________ layer that is used for local storage

Answer 9

When a container is launched, it gets one final layer called the writable layer that is used for local storage

Question 10

When two containers are launched from the same image, this w________ layer is what distinguishes them from one another.

Answer 10

When two containers are launched from the same image, this writable layer is what distinguishes them from one another.

Question 11

The writable layer is not p________ and is lost between starts and stops.

Answer 11

The writable layer is not persistent and is lost between starts and stops.

Question 12

docker images are r____-only and i________able

Answer 12

docker images are read-only and immutable

Question 13

Docker supports a temporary filesystem called t____s, which is stored in memory (RAM)

Answer 13

Docker supports a temporary filesystem called tmpfs which is stored in memory (RAM)

Question 14

B____ m____ maps a host folder to a container folder, allowing the container to access files on the host.

Answer 14

Bind mount maps a host folder to a container folder, allowing the container to access files on the host.

Question 15

V_____s are persistent storage that are managed by docker but utilize the host machine. They allow you to create persistence storage that exists outside of the lifecycle of an individual container.

Answer 15

Volumes are persistent storage that are managed by docker but utilize the host machine. They allow you to create persistence storage that exists outside of the lifecycle of an individual container.

Question 16

Containers on the same b____ network can communicate with one another but can’t be reached from outside the docker host without port publishing.

Answer 16

Containers on the same bridge network can communicate with one another but can’t be reached from outside the docker host without port publishing.

Question 17

P____ p____ing maps a host port to a container port on the bridge network. This allows requests made to the host port to access the container port and the running process within it.

Answer 17

Port publishing maps a host port to a container port on the bridge network. This allows requests made to the host port to access the container port and the running process within it.

Question 18

by utilizing a b_____ network, multiple containers can share the same port number. However, to make them accessible from outside the internal network, the port must be mapped to unique and unused ports on the host machine.

Answer 18

by utilizing a bridge network, multiple containers can share the same port number. However, to make them accessible from outside the internal network, the port must be mapped to unique and unused ports on the host machine.

Question 19

C____s can be connected to a bridge network. Each container gets a unique, private __ address on this network. Each container can use the same p___ because the IP is unique

Answer 19

Containers can be connected to bridge network
Each container gets a unique, private IP address on this network. Each container can use the same port because the IP is unique

Question 20

By using bridge networking and publishing containers, we can publish the same container to different host p____s

Answer 20

By using bridge networking and publishing containers, we can publish the same container to different host ports

Question 21

I___ is pre-cooked, frozen treat.
C____ is the delicious treat.

Answer 21

Image is pre-cooked, frozen treat.
Container is the delicious treat.

Question 22

the Docker engine will take care of turning the immutable files called i____s into c_____s.

Answer 22

the Docker engine will take care of turning the immutable files called images into containers.

Question 23

If we do not specify a W_____, we risk overwriting important files by accident

Answer 23

If we do not specify a WORKDIR, we risk overwriting important files by accident

Question 24

This is a critical thing to keep in mind when we build our images. It’s best to do most things, such as to run npm install during the build process i_____ the container rather than doing those prior to building.

Answer 24

This is a critical thing to keep in mind when we build our images. It’s best to do most things, such as to run npm install during the build process inside the container rather than doing those prior to building.

(Instead of using npm install, npm offers a much better tool for installing dependencies, the ci command)

Question 25

Instead of using npm install, npm offers a much better tool for installing dependencies, the __ command.

Answer 25

Instead of using npm install, npm offers a much better tool for installing dependencies, the ci command.

Question 26

Differences between ci and install:

install may update the package-lock.json
install may install a different version of a dependency if you have ^ or ~ in the version of the dependency.
ci will d____ the node_modules folder before installing anything
ci will follow the package-lock.json and does not alter any files
So in short: ci creates reliable b____s, while install is the one to use when you want to install new d_________s.

Answer 26

Differences between ci and install:

install may update the package-lock.json
install may install a different version of a dependency if you have ^ or ~ in the version of the dependency.
ci will delete the node_modules folder before installing anything
ci will follow the package-lock.json and does not alter any files
So in short: ci creates reliable builds, while install is the one to use when you want to install new dependencies.

Question 27

As we are not installing anything new during the b____ step, and we don’t want the v_____s to suddenly change, we will use ci

Answer 27

As we are not installing anything new during the build step, and we don’t want the versions to suddenly change, we will use ci

Question 28

we can use npm ci –o___=d___ to not waste time installing development dependencies.

Answer 28

we can use npm ci –omit=dev to not waste time installing development dependencies.

Question 29

There are 2 rules of thumb you should follow when creating images:

Try to create as s____ of an image as possible
Try to create as s____ of an image as possible

Answer 29

There are 2 rules of thumb you should follow when creating images:

Try to create as secure of an image as possible
Try to create as small of an image as possible

Question 30

Don’t run containers as r____

Answer 30

Don’t run containers as root

Question 31

Use e_____ and d_______ Docker base image tags

Answer 31

Use explicit and deterministic Docker base image tags

Question 32

Bind mount is the act of binding a file (or directory) on the h___ machine to a file (or directory) in the c______

Answer 32

Bind mount is the act of binding a file (or directory) on the host machine to a file (or directory) in the container

Question 33

The Docker command e____ is a heavy hitter. It can be used to jump right into a container when it’s running.

Answer 33

The Docker command exec is a heavy hitter. It can be used to jump right into a container when it’s running.

Question 34

There are actually _ different forms for CMD, out of which the e___ form is preferred.

Answer 34

There are actually three different forms for CMD, out of which the exec form is preferred.

Question 35

During build the flag -_ will be used to tell which file to use, it would otherwise default to Dockerfile

Answer 35

During build the flag -f will be used to tell which file to use, it would otherwise default to Dockerfile

Question 36

B_____ is a small executable with multiple tools and is called “The Swiss Army Knife of Embedded Linux”

Answer 36

Busybox is a small executable with multiple tools and is called “The Swiss Army Knife of Embedded Linux”