I took the DCA (Docker Certified Associate) today and failed! This should be a reality check that I should have had earlier and should have more frequently. What is rational to do now is to pinpoint whys and hows (I failed and do next).
Why I failed?
Obviously, I haven’t had enough commercial experience with Docker. It’s not enough to memorise syntax of commands, even though it’s part of the test. What is harder is to understand which context should I use those commands. For example, it’s not sufficient to remember `docker system df`, but to understand that we often use this command to check how much storage docker objects are taking and appropriate actions.
This not-pass-yet experience also reminds me that I don’t remember commands as well as I thought. Very often I confused similar commands or was not aware of short and different versions of one command.
Secondly, sometimes I forget whether this test is about Docker or Kubernetes. The curriculum includes docker orchestration, and I assume it was mostly about Docker Swarm. However, there are as many questions about K8S as those about Docker Swarm. I only spent few days to learn about K8S, so this failure is very well worth.
Finally, Docker EE. The biggest problem is questions about docker enterprise edition, and this often comes with questions about security, setting up and user management. Again, the question is rather situational and detail-oriented. There’s some confusion in the old and new names of enterprise version! It’s rather hard to look up something in Mirantis documentation.
What should I do?
Three things to do immediately:
Have more hands-on experience with Docker. This can be done via labs provided via docker Github repository or in the DCA book that I’m reading. K8S also provide a lot of labs that I can learn from. Try to test myself by setting up tasks and see if I can do complete it without looking at the tutorials. More importantly, I have have to make notes of major steps, misunderstanding and nuances of Docker objects
Review docker command as regularly as possible. This can be done via practicing tests and reading notes as well. Side note: I attribute this not-pass-yet experience to my fragmented note-taking system as well.
Have more exposure to docker enterprise edition. I’m still figuring out how to do this!
Things not to do!
Don’t be a smart ass on Stackoverflow
Don’t learn in fragmented ways. Try to contextualise what you have learned with labs or writing posts
Don’t give up!
So, that’s it for now. You can easily measure your progress with your notes, labs and reflections.