Docker Basics

Question 1

Command to get docker version

Answer 1

docker –version

Question 2

What is docker hub

Answer 2

• Docker hub is a public docker registry at hub.docker.com
• anyone can access these images

Question 3

route to find docker image registries in docker hub

Answer 3

• http://hub.docker/r/{ imagename }
• registries hold repositories.
• repository:version

Question 4

How to specify the port in a docker run

Answer 4

• docker run -p { port1 }:{ port2 }
• docker run -p { 5000 }:{ 5000 }
• -p is short for publish.

Question 5

What is it called when an image is running?

Answer 5

a container

Question 6

What is the bridge network

Answer 6

Internal docker network. All containers run inside the bridge network. You cannot access the container unless the container is exposed to the outside.

Question 7

What is the first port and second port of a specified docker container. EX: 5000:5000

Answer 7

The first port number is a host port and the second is the container port

Question 8

How to launch docker container detached from the command line

Answer 8

add a { -d } to the docker run command

Question 9

command to print out logs

Answer 9

docker logs { container id/name }

Question 10

how to follow the logs of a docker container

Answer 10

-f
exL docker logs -f { container id/name }

Question 11

How to list out images created

Answer 11

docker images

Question 12

how to list all the running containers

Answer 12

docker container ls

Question 13

how to follow the logs of a docker container

Answer 13

-f
ex: docker logs -f { container id/name }

Question 14

what option allows you to list out all the docker containers. Even the ones that have been exited

Answer 14

-a
docker container ls -a

Question 15

What is the docker Client?

Answer 15

Docker client takes our commands and sends them to the docker daemon.
- It pulls images
- Manages your containers
- pushes images to the repository

Question 16

What is the docker daemon

Answer 16

Docker daemon is the server side. Docker is a client server architecture

Question 17

How to download an image to local storage

Answer 17

pull
docker pull {image}

Question 18

How to see the layers of a docker image

Answer 18

history
docker image history { image }

Question 19

How to find specs/metadata about the docker image

Answer 19

inspect
docker image inspect { image }

Question 20

how to remove an image

Answer 20

remove or rm
docker image rm { image_name }

Question 21

How to pause a container

Answer 21

pause
docker container pause { image_name }

Question 22

How to restart a paused docker container

Answer 22

docker container unpause { image_name }

Question 23

What is the difference from docker container stop and kill?

Answer 23

Docker container stop gracefully closes the processes that are running.
docker container kill sends the command sig kill. This drops everything and terminates it right away. Is not graceful

Question 24

Get details about a container

Answer 24

inspect
docker container inspect { id/name }

Question 25

How to remove containers that are stopped

Answer 25

docker container prune

Question 26

How to get general docker information on the hardware

Answer 26

docker system { option }

Question 27

Get rid of all the Exited containers and images that are not used

Answer 27

docker system prune -a

Question 28

Command used to print the amount of resources being used by docker containers

Answer 28

docker stats
docker stats -f

Question 29

How to set the limit of memory a docker container can use

Answer 29

-m 512m

ex: socker container run -p 5000:5000 -d -m 512 {image}

Question 30

Specifiy what percentage of the cpu can be used by the docker container

Answer 30

–cpu-quota=50000
ex: socker container run -p 5000:5000 -d -m 512 –cpu-quota=500000 {image}