Book Review: The Docker Book
Docker is an open-source project that automates the deployment of applications inside software containers. I’m responsible for a docker setup with Jenkins integration and a private docker-registry setup at a customer and pre-ordered James Turnbull’s “The Docker Book” a few months ago.
Recently James – he’s working for Docker Inc – released the first version of the book and thanks to being on holidays I already had a few hours to read it AND blog about it. :) (Note: I’ve read the Kindle version 1.0.0 and all the issues I found and reported to James have been fixed in the current version already, jey.)
The book is very well written and covers all the basics to get familiar with Docker and in my opinion it does a better job at that than the official user guide because of the way the book is structured. The book is also a more approachable way for learning some best practices and commonly used command lines than going through the official reference (but reading the reference after reading the book is still worth it).
I like James’ approach with “ENV REFRESHED_AT $TIMESTAMP” for better controlling the cache behaviour and definitely consider using this in my own setups as well. What I wasn’t aware is that you can directly invoke “docker build $git_repos_url” and further noted a few command line switches I should get more comfortable with. I also plan to check out the Automated Builds on Docker Hub.
There are some references to further online resources, which is relevant especially for the more advanced use cases, so I’d recommend to have network access available while reading the book.
What I’m missing in the book are best practices for running a private docker-registry in a production environment (high availability, scaling options,…). The provided Jenkins use cases are also very basic and nothing I personally would use. I’d also love to see how other folks are using the Docker plugin, the Docker build step plugin or the Docker build publish plugin in production (the plugins aren’t covered in the book at all). But I’m aware that this are fast moving parts and specialised used cases – upcoming versions of the book are already supposed to cover orchestration with libswarm, developing Docker plugins and more advanced topics, so I’m looking forward to further updates of the book (which you get for free as existing customer, being another plus).
Conclusion: I enjoyed reading the Docker book and can recommend it, especially if you’re either new to Docker or want to get further ideas and inspirations what folks from Docker Inc consider best practices.