Docker

Question 1

How to see list of running containers in Docker?

Answer 1

docker container ls

docker container ls -a —– (show all containers)

Question 2

how to remove container in Docker?

Answer 2

docker container rm [container id]

container id can be only first 3 digits

Question 3

Create an run a container in foreground [Docker]

Answer 3

$ docker container run -it -p 80:80 nginx

Question 4

Create an run a container in background

Answer 4

$ docker container run -d -p 80:80 nginx

Question 5

difference between running container in foreground and background docker

Answer 5

You can start a docker container in detached mode with a -d option. So the container starts up and run in background. That means, you start up the container and could use the console after startup for other commands.

The opposite of detached mode is foreground mode. That is the default mode, when -d option is not used. In this mode, the console you are using to execute docker run will be attached to standard input, output and error. That means your console is attached to the container’s process.

In detached mode, you can follow the standard output of your docker container with docker logs -f .

Question 6

List running containers [Docker]

Answer 6

$ docker container ls

$ docker ps

Question 7

List all containers (Even if not running) [Docker]

Answer 7

$ docker container ls -a

Question 8

Stop container
Stop all running containers
[Docker]

Answer 8

$ docker container stop [ID]

$ docker stop $(docker ps -aq)

Question 9

Remove container (Can not remove running containers, must stop first)
To remove a running container use force(-f)

Answer 9

$ docker container rm [ID]

$ docker container rm [ID] [ID] [ID]

Question 10

Get logs (Use name or ID) [Docker]

Answer 10

$ docker container logs [NAME]

Question 11

List processes running in container [Docker]

Answer 11

$ docker container top [NAME]

Question 12

Docker containers are often compared to virtual machines but they are actually just processes running on your host os. In Windows/Mac, Docker runs in a mini-VM so to see the processes youll need to connect directly to that. On Linux however you can run “ps aux” and see the processes directly

Question 13

Remove all images [Docker]

Answer 13

$ docker rmi $(docker images -a -q)

Question 14

About images [Docker]

Answer 14

• Images are app bianaries and dependencies with meta data about the image data and how to run the image
• Images are no a complete OS. No kernel, kernel modules (drivers)
• Host provides the kernel, big difference between VM

Question 15

View info on container [Docker]

Answer 15

$ docker container inspect [NAME]

Question 16

Specific property (–format) for container [Docker]

Answer 16

$ docker container inspect –format ‘{{ .NetworkSettings.IPAddress }}’ [NAME]

Question 17

Use exec to edit config, etc [Docker]

Answer 17

$ docker container exec -it mysql bash

Question 18

Get port for network [Docker]

Answer 18

$ docker container port [NAME]

Question 19

Connect existing container to network [Docker]

Answer 19

$ docker network connect [NETWORK_NAME] [CONTAINER_NAME]

Question 20

what is Volume? [Docker]

Answer 20

Makes special location outside of container UFS. Used for databases

Question 21

Bind Mount what is it? [Docker]

Answer 21

Link container path to host path

Question 22

Cleanup unused volumes

[Docker]

Answer 22

$ docker volume prune

Question 23

docker-compose CLI - used for ?

Answer 23

local dev/test automation with YAML files