Docker

Question 1

What is the Docker command to run a container?

Answer 1

docker run image

Question 2

docker run -d image

Answer 2

Runs the container in detached mode (in the background)

Question 3

docker run -p 80:80 image

Answer 3

Map port 80 of the host to port 80 in the container

Question 4

How to make…

docker run -d -p image

…more compact?

Answer 4

docker run -dp image

Question 5

What is a container?

Answer 5

A process on the host machine that has been isolated from all other processes of the host machine

Question 6

What does the process isolation leverages?

Answer 6

the kernel namespaces and cgroups

Question 7

docker ps

Answer 7

List running containers

Question 8

When running a container, it uses an _____ filesystem.

Answer 8

isolated

Question 9

The isolated filesystem that a running container uses is provided by…

Answer 9

a container image

Question 10

Since the image contains the container’s filesystem, it must contain…

Answer 10

everything needed to run an application - all dependencies, configuration, scripts, binaries, etc.

Question 11

What is chroot?

Answer 11

?

Question 12

In order to build our application, we need to use a…

Answer 12

Dockerfile

Question 13

A Dockerfile is a…

Answer 13

text-based script of instructions that is used to create a container image

Question 14

The CMD directive specifies…

Answer 14

the default command to run when starting a container from this image

Question 15

The FROM instructions initializes…

Answer 15

a new build stage and sets the Base Image for subsequent instructions

Question 16

The WORKDIR instruction sets…

Answer 16

the working directory for any RUN, CMD, ENTRYPOINT, COPY and ADD instructions that follow it in the Dockerfile

Question 17

The COPY instruction copies…

COPY src dest

Answer 17

new files or directories from src and adds them to the filesystem of the container at the path dest

Question 18

What does the -t flag does?

Answer 18

It tags our image

Question 19

Command to stop a running container:

Answer 19

docker stop

Question 20

Command to remove a container that has stopped:

Answer 20

docker rm

Question 21

What does the -f do in that context:

docker rm -f

Answer 21

It removes the container even if it is running

Question 22

How do we tag an image?

Answer 22

docker tag imageName newImageName

Question 23

How do we remove an image?

Answer 23

docker rmi imageId