README.md

Docker Tasks

General Docker Tips

• For tasks that require you to troubleshoot a Dockerfile or create a Dockerfile, make sure you test the file by running a docker build on the same directory as Dockerfile: docker build -t my_image .
• Another important tip is to make use of the free Katakoda Docker Playground to test your Docker changes. So the recommendation is to:
  • Open the task in Kodekloud Engineer, note down the question and press Try Later
  • Open KataKoda Playground, prepare docker commands, execute and test your changes until you are satisified
  • Reopen question in Kodekloud Engineer, apply your changes and verify. Bam! You finished your task in time for bonus points.
• Always verify the successful completion of the task using one or more of the approaches below:
  • Use browser by clicking Open Port on Host 1 tab especially for tasks that ask you to configure a Host Port (Docker).
    • Click Open Port on Host 1 tab and specify the port and click Connect
    • Check that the URL loads.
  • Exec command - Especially useful to verify tasks that involve running a server listening to a port e.g. Nginx, HTTPD (or) Verify volume mounts
    • docker exec -it <container_id_or_name> <command>
    • Examples:
      • docker exec -it nginx_ubuntu ls /tmp/execWorks
  • Shell - You can also get a shell to a Docker Container like this. This is useful when you need to run multiple verification commands:
    • docker exec -it nginx_ubuntu /bin/bash
  • Logs - Useful for tasks that require you to print an output e.g. echo:
    • docker logs -f <container_id_or_name>. For example, docker logs -f nginx_ubuntu

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For general tips on getting better at KodeKloud Engineer tasks, click here