How can the logs inside a running container be viewed?

To view the output logs inside a running Docker container, use the command:

docker logs <container_id_or_name>

This command displays the standard output (stdout) and standard error (stderr) of the container. You can add the -f flag to view logs in real-time:

docker logs -f <container_id_or_name>

If the container uses a logging system, such as with the journald or json-file driver, the docker logs command will show the corresponding logs.