David Currie

I picked up a copy of Docker in Production – Lessons from the Trenches during a recent O’Reilly sale, hoping to pick up some tips to pass on to customers that I work with. I have to say that I was disappointed! It’s not that the book isn’t full of useful information. It is. After a good start, it just failed to deliver on the title for me.

After covering the basics and the likely areas of concern, it introduces an example with the wise words that not everyone is looking to deploy a platform for running tens of thousands of containers and that even small deployments can benefit from their use. The example describes a simple environment using systemd to stand up a static topology with the ability to provide environment specific configuration. Just the sort of concrete material I was hoping for.

The next couple of chapters provided further examples from a second company: one using a simple scripted approach and another using AWS Beanstalk. So far, so good. At this point the book changed tack though and switched to covering different subject areas such as security, building and storing images, configuration management, networking, scheduling, service discovery, and concluding with logging and monitoring. Although, as I say, there was lots of good information scattered throughout, these chapters somehow felt like they were just giving an overview of the current state of the Docker ecosystem without giving much in the way of guidance as to how to select from the myriad of options to create a production-ready solution.

Perhaps I’m being unfair and this is simply a reflection on the current state of play. Whilst the Docker feature set is still being fleshed out there are still many compromises to be made and over time we may see more repeatable deployment patterns emerging. The fact that much of the material in the book was not new to me is probably a reflection of the efforts I am taking to keep up with what is a rapidly transforming area.

One final thought: it will be interesting to contrast this book with the free eBooks series that The New Stack has just begun. The first book, entitled “The Docker and Container Ecosystem”, includes some interesting metrics to suggest who are the main players. The catalogue of services and projects that form the second half of the book is truly eye-watering and whilst it can be seen as an indicator of vibrancy, it does indicate a real need to be able to provide guidance to those who do not have the time or inclination to immerse themselves in this world.

On Friday I made my way up to the Barbican Centre for this year’s edition of Container Camp London. After a slow start (no-one seemed to know that we were supposed to descend five floors to the cinema in the bowls of the building) things finally got under way. Here’s a quick summary of the day’s sessions:

• Bryan Cantrill, CTO at Joyent kicked off the day with a animated romp through the history of containers ending with the view that containers deserve better than to be run in virtual machines and, perhaps not surprisingly, Joyent’s Triton project gives you the ability to turn the bare metal in your datacenter in to one large virtualized container host.
• Next up (after another hiatus to sort out projector woes) was Shannon Williams, co-founder of Rancher Labs. He talked about what you should be looking for in a private container service which again, not surprisingly, read much like a feature list for Rancher.
• Lack of network connectivity was the next issue which saw Bryan Boreham from Weaveworks take to the stage. Byran gave a technical presentation describing why consensus (as used by Consul or etcd) may be overkill and why Weave uses conflict-free replicated data types (CRDT) for service discovery and IP address management.
• Mandy Waite from Google gave an introduction to Kubernetes – nothing new there.
• Stephane Graber, who is the project lead for LXD at Canonical, gave a nice demo of some of the capabilities of LXD. He stressed that LXD is aimed aimed at system (i.e. whole OS) containers rather than application containers, suggesting, for example, that you might run Kubernetes under LXD. He failed, however, to explain what features differentiated it in this respect.
• There was selection of lightning talks over lunchtime, most of which now escape me. Ben Corrie from VMware spoke about Project Bonneville, demonstrating vSphere as a container host. Liz Rice would have demonstrated the real-time scaling of force12.io if she’d been able to connect to the screen.
• After lunch, Arjan Schaaf from Luminis illustrated that, as always, you should performance test. In this case, to understand the inter-container networking characteristics of your IaaS and SDN.
• Alissa Bonas from Redhat demonstrated the OpenShift/Kubernetes integration in ManageIQ that allows you to drill down from a container view of the world in to the underlying infrastructure (virtual or physical).
• Miek Gieben spoke about the dynamic, container-based infrastructure that powers Improbable.io based on Core OS, fleet, etcd and DNS.
• After yet another coffee break (queue trek back up five flights of stairs), Ben Hall gave an entertaining pitch on attempting to keep nefarious users at bay whilst giving them free reign over a Docker setup in his Scrapbook learning environment.
• This was followed by Diogo Monica of Docker cover the Notary and the Trusted Update Framework as integrated with Docker 1.8. I was just glad that I had saved watching Docker Online Meetup #24 for the journey home as it was the same slidedeck.
• Perhaps the most impressive session of the day was by Loris Degioanni, CEO at Sysdig. He started by talking about monitoring through tools such as Google’s cadvisor and Docker logs before giving a really powerful demonstration of the sort of information you could collate and navigate by inserting the sysdig kernel module on the Docker host.
• Last up was Juan Batiz-Benet who, although his presentation was entitled ‘Containers at Hyperspeed’ was, I suspect, going a little too fast for most people to keep up! The net was though that we should all be using IPFS to shift images around so that deduplication doesn’t stop at container layers but goes down to the individual file level.

As you can probably tell from my comments, the conference could have been slicker but it was still well worth the trip up to London. I’d say I learnt less than last year but that’s more because my own level of understanding has moved on. I’d also suggest that this year there was more of a focus on ‘doing with Docker’ than simply on the technology itself which indicates an increase in the maturity of the ecosystem.