How to see the logs of a docker container

Question

I have a simple code for which I have created a docker container and the status shows it running fine. Inside the code I have used some print() commands to print the data. I wanted to see that print command output.

For this I have seen docker logs . But it seems not to be working as it shows no logs. How to check logs.?

 $ sudo docker ps
CONTAINER ID        IMAGE                        COMMAND                  CREATED             STATUS              PORTS                                            NAMES
a3b3fd261b94        myfirstdocker                     "python3 ./my_script…"   22 minutes ago      Up 22 minutes                                                        elegant_darwin

 $ sudo docker logs a3b3fd261b94
 <shows nothing>

Answer 1

The first point you need to print your logs to stdout.

To check docker logs just use the following command:

docker logs --help

Usage:  docker logs [OPTIONS] CONTAINER

Fetch the logs of a container

Options:
      --details        Show extra details provided to logs
  -f, --follow         Follow log output
      --help           Print usage
      --since string   Show logs since timestamp
      --tail string    Number of lines to show from the end of the logs (default "all")
  -t, --timestamps     Show timestamps

Some example:

docker logs --since=1h <container_id>