Suggestions to improve knowledge on docker

I am new to Docker and tried some hands-on (not deeper learned upto basics of image,container) by following docker official documentation.

To take my learning curve to next level, I have implemented what I read by taking sample applications like "Dockerising a Node.js and MongoDB App by nida sajid", run a sample java restful webapplication which takes name and
email and storing it into mysql container. I've done this by using 2 containers:

• tomcat - Used to deploy war file

• mysql - To store the data(name&email))

My question: what are the advanced concepts that I can learn and, can you suggest me so that I can improve my knowledge

• What are the advanced concepts in docker other than this (like used in real world scenario)?

• Any suggestions (like websites,videos) to improve my knowledge?

• How to use Docker with Jenkins?

Some good next topics for the real world are...

• Security. There are several security concerns with docker, for example

• Is there a problem running stuff inside the container as root?

• Is there a problem giving non-root users on the host access to the docker daemon?

• Is there a problem with the docker daemon running as root on the host?

• All three can be solved with docker out-of-the-box. Learn how to.

• Networking. Check out the docker networking options.

• Image sizes are a recurring problem, especially if you build your stuff inside a docker image. Your average naive first build image may be 1GB or more - try to get the same image, whatever it is, to 500, 300 or 200 MB.

• Docker volumes; how to get configuration into your containers; etc.

• Private artifact repositories.

• Explore the environment: docker compose, docker swarm, etc.

• Finally, take a big leap on to your next technology... OpenShift? Kubernetes?

StackExchange DevOps Q#2631, answer score: 5