labs-02.md

Labs: Managing Containers

List the Images

docker image ls

What images are already on the docker host? These were automatically pulled from previous docker container run commands.

Pull Another Image

docker image pull busybox:latest

What would have happened if we left off the ":latest" tag?

List Only The Pulled Image

docker image ls busybox:latest

Formatting the Output

docker image ls --format 'table {{.ID}}\t{{.Size}}'

Start a Container in the Background

docker container run -d nginx

List Containers

docker container ls

That shows the "nginx", but what if we also show stopped containers:

docker container ls -a

Restart a Container

Find the older "centos" container that's been stopped above, and restart it (note that newer containers are at the top of the list):

docker container restart ${container_id}

See if you can find the "/demo.txt" file that we created in the last lab:

docker container exec ${container_id} ls -l /

View Container Logs

docker container logs ${container_id}

You should see the output from when the container was run, but not the commands that launched with docker container exec.

What if we had lots of logs? Lets start a container that will generate lots of lines of output:

docker container run -d --name pinger busybox ping 8.8.8.8

Let it run for 5 seconds, and then run:

docker container logs --since 5s pinger

Notice how we used a container name to avoid needing to lookup the id.

Cleanup

First, verify that your container is running:

docker container ls

Now stop any running containers:

docker container stop ${container_id}

This may take 10 seconds, why?

Now delete each of the exited containers:

docker container rm ${container_id}