Viewing container logs in Docker - Cheat Sheet & Quick Revision

Recall & Review

beginner

What command shows the logs of a running Docker container?

Use docker logs <container_name_or_id> to see the output and messages from a running container.

beginner

How do you follow the logs in real-time for a Docker container?

Add the -f or --follow option: docker logs -f <container_name_or_id> to watch new log entries as they appear.

intermediate

How can you limit the number of log lines shown from a Docker container?

Use the --tail <number> option, for example: docker logs --tail 10 <container_name_or_id> shows only the last 10 lines.

beginner

What does the docker logs command show by default?

It shows all the logs that the container has produced since it started, including standard output and standard error.

intermediate

Can you view logs of a stopped Docker container?

Yes, docker logs works for stopped containers too, showing the logs they produced before stopping.

Which command shows the logs of a Docker container named 'webapp'?

A docker logs webapp

B docker show logs webapp

C docker container logs webapp

D docker view logs webapp

The correct command is docker logs webapp to view logs.

How do you watch logs live as they are generated?

A docker logs --tail 10

B docker logs --start

C docker logs -f

D docker logs --stop

Use docker logs -f <container> to follow logs live.

What option limits the number of log lines shown?

A --limit

B --tail

C --head

D --lines

The --tail option limits log lines shown.

Can you view logs of a container that is not running?

A Only if you restart the container first

B No, logs are only available for running containers

C Only if the container was stopped less than 5 minutes ago

D Yes, logs are saved and can be viewed anytime

Docker saves logs and you can view them even after the container stops.

What does the docker logs command show by default?

A All output since container start

B Only the last 10 lines

C Only error messages

D Only logs from the last hour

By default, it shows all logs since the container started.

Explain how to view and follow logs of a Docker container in real-time.

Think about how you watch a live video feed of logs.

Describe how to limit the number of log lines shown when viewing Docker container logs.

Imagine you only want to see the last few messages, not everything.