Popular docker cmds

Question 1

docker run -it ubuntu:latest bash

Answer 1

create a container with the latest ubuntu image running an interactive bash shell

Question 2

How to list all active running containers

Answer 2

docker ps

Question 3

how to see stopped containers

Answer 3

docker ps -a

Question 4

docker run –rm “IMAGE NAME/ID”

Answer 4

remove the container after stopping, otherwise container will remain

Question 5

How to attach/connect to a running container

Answer 5

docker attach docker run –rm “CONTAINER NAME/ID”

entering and exiting a bash container will shutdown the container

Question 6

how to list last container closed

Answer 6

docker ps -l

Question 7

how to name a new image?

Answer 7

docker tag “ID” “NEW IMAGE NAME”

Question 8

How to commit new changes to a container to a new image and rename the new image

Answer 8

docker commit “CONTAINER NAME/ID”

This will create a new image, but with no name.

The original container will continue unaffected

will return a large number, that can be used to name the image:

docker tag <> <>

Question 9

How to run docker with an interactive terminal?

Answer 9

docker run -it

Question 10

How to run a detached container

Answer 10

Use -d flag with run

docker run -d <>

Question 11

How to exit an attached container without stopping it

Answer 11

CTRL p CTRL q

Question 12

How to start a new process in an existing container?

Answer 12

docker exec -ti <> <>

example:

docker exec -it <> bash

Question 13

how to create a detached container?

Answer 13

docker -d

Question 14

docker run -d “IMAGE NAME/ID”

Answer 14

How to create a detached container

Question 15

How to start a stopped container?

Answer 15

docker start “CONTAINER NAME/ID”

Question 16

How to restart a docker container?

Answer 16

docker restart “CONTAINER NAME/ID”

If the container is already stopped, then this cmd is the same as start

Question 17

How to stop a container

Answer 17

docker kill “CONTAINER NAME/ID”

this sends a SIGKILL to main process

or

docker stop “CONTAINER NAME/ID”

this sends a SIGTERM then a SIGKILL to main process

Question 18

How to look a logs for a container

Answer 18

docker logs “CONTAINER NAME/ID”

Question 19

How to remove a container?

Answer 19

docker rm “CONTAINER NAME/ID”

Question 20

How can you limit resource consumption by containers

Answer 20

Memory limits:

docker run –memory “CONTAINER NAME/ID”

CPU limits

docker run –cpu-share/–cpu-quota “CONTIANER NAME/ID”

Question 21

how to publish a port in docker

Answer 21

docker run -p hostpPort:containerPort

Question 22

how to list networks in docker

Answer 22

docker network ls

Question 23

how to list port mapping in a container?

Answer 23

docker port “CONTAINER NAME/ID”

Question 24

How to create a network?

Answer 24

docker network create “NETWORK NAME”

Question 25

How to create a container for a specific network?

Answer 25

docker run –net “NETWORK NAME/ID” “IMAGE NAME”