Running Your First Container

Time to run real containers. You'll launch apps from images, interact with them, and learn the commands that manage their lifecycle.

docker run is your launch button: it checks for the image (pulling if needed), creates a container from it, and starts it — all in one command.

Run the simplest container there is: hello-world. It prints a message and exits. Try it below.

Behind that hello-world run, Docker pulled the image, created a container, ran its command, printed the greeting, then stopped. A clean first cycle.

To work inside a container, combine the -it flags: -i keeps STDIN open and -t gives you a terminal, so you can type commands inside it.

Spin up minimal Alpine Linux and drop into its shell to run real Linux commands. Type exit to leave the container.

To keep a container running without locking your terminal, use detached mode with the -d flag. Docker prints the container ID and hands control back.

Containers are isolated, so reach a service inside one with port mapping. The -p flag maps a host port to a container port: host:container.

Combine detached mode and port mapping to run Nginx in the background, mapping your host's 8080 to the container's port 80. See the command below.

Clean up when you're done: docker stop halts a running container and docker rm removes a stopped one. Grab the ID from docker ps first.

You want to run a container and immediately get a shell inside it to execute commands. Which option would you use with docker run?

Recap: docker run launches containers; -it gives a shell, -d runs detached, -p maps ports — plus stop and rm to clean up afterward.