Basic Commands

Question 1

Where do you run docker commands?

Answer 1

Run commands using command line from the root of your application

Question 2

docker pull

Answer 2

Retrieve an image from a registry. If you specify only the repository name, Docker will download the image tagged latest from that repository on Docker Hub.
e.g. docker pull mcr.microsoft.com/dotnet/core/aspnet:3.1 pulls the 3.1 runtime, where docker pull mcr.microsoft.com/dotnet/core/sdk pulls the latest .NET Core SDK.

Question 3

docker build

Answer 3

Create a new image by running a Dockerfile. Use the -t flag to specify the name of the new image and don’t forget the . (build context for the source files for the COPY command)
e.g. docker build -t image.name.for.my.app:v1 .

Question 4

docker image list

Answer 4

After pulling an image, view the images in your local registry with the docker image list command.

Question 5

docker ps

Answer 5

View active containers. Use the -a flag to view all.
e.g. docker ps -a

Question 6

docker run

Answer 6

Run an image – it will become a container. Specify the option -p for port mapping (left hand side local port, right hand side port exposed by docker) and -d to run it as a background service.
Speficy the –name option to set the name of the container.
e.g. docker run -p 8080:80 -d –name container.name image.name.for.my.app

Question 7

docker stop

Answer 7

Stop an active container by specifying the container ID. Get that with the docker ps command
e.g. docker stop elegant_ramanujan

Question 8

docker start

Answer 8

Restart a stopped container.
e.g. docker start elegant_ramanujan

Question 9

docker container rm

Answer 9

Remove a stopped container. Add the -f flag to force remove a running container (not a graceful shutdown)
e.g. docker container rm -f elegant_ramanujan

Question 10

docker image rm

Answer 10

Remove an image. There is no force flag here, all containers using this image must be stopped.
e.g. docker image rm mcr.microsoft.com/dotnet/core/samples:aspnetapp