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The container wars have started!

Containers have a huge amount of hype and momentum, and there are many spoils for whoever becomes dominant in the container ecosystem. The two major startups innovating in this space–CoreOS and Docker–have waged war on each other as part of gaining that control.

The Current Landscape

On Monday, CoreOS announced Tectonic. Tectonic is a full solution for running containers, including CoreOS as the host OS, Docker or rkt as the container format, and Kubernetes for managing the cluster. It also uses a number of other CoreOS tools, such as etcd and fleet.

Despite Docker being an option on Tectonic, CoreOS’s messaging is not focused on Docker, and neither the Tectonic site nor the announcement including a single mention of Docker. It’s clear that CoreOS is moving in a different direction. CoreOS’ CEO Alex Polvi says that “Docker Platform will be a choice for companies that want vSphere for containers”, but that Rocket is the choice for “are enterprises that already have an existing environment and want to add containers to it”. The latter is a far larger prize.

Companies will choose Docker Platform as an alternative to things like Cloud Foundry. Companies like Cloud Foundry will use things like Rocket to build Cloud Foundry.

Docker meanwhile, doesn’t mention CoreOS or Kubernetes anywhere in their docs, and on their site only mentions them in passing. Docker CEO Solomon Hykes reacted fairly negatively to the announcement of rkt back in December. He has also started to use the phrase “docker-native” to differentiate tools that Docker Inc builds from other tools in the ecosystem, indicating other tools are second class.

Diverging Stacks

Right now, both companies provide different pieces with their respective stacks and platforms.

To run containers successfully on infrastructure, you need a host OS, the container runtime, and some sort of orchestration. Tectonic provides all of these, with CoreOS, Docker or rkt, and Kubernetes. However, it appears to omit an opinionated way to build a container image, their equivalent of the Dockerfile. This is by design, and there are many ways to build images (Chef, Puppet, Bash, etc).

On Docker, things are less clear. Docker isn’t opinionated on the host OS, but also doesn’t provide much help there. Docker Machine abstracts over it for some infrastructure services, where you use whatever host OS exists already, but doesn’t provide much help when you want to run the whole thing. Docker Swarm and Docker Machine provide some parts of orchestration. There is also Docker compose, which Docker has been recommending as part of this puzzle, but simultaneously saying it’s not intended to be used as part of production. Of course they have a Dockerfile to build the containers, though some indicate that this is immature for large teams.

The impression you get from Docker is that they want to own the entire stack. If you visit the Docker site, you could be forgiven for thinking that the only tools you use with Docker are Docker Inc’s tooling. However, Docker doesn’t really have good solutions for the host OS and orchestration components at present.

Similarly, Docker are pushing their own tools instead of alternatives, even when those tools aren’t really valid alternatives. Docker Compose, for example, is being pushed as an orchestration framework though this feature is still in the roadmap.

Mindshare

The container landscape is fairly new, but Docker has a pretty clear lead in terms of mindshare. Both companies are trying to control the conversation: Docker talking about Docker-native and generally focussing it’s marketing around the term Docker, while others in the space - CoreOS and Google for example - are focussing the conversation on “containers” rather than “Docker”.

This is made a little bit difficult by the head start that Docker has - they basically created the excitement around containers, and most people in the ecosystem talk about Docker rather than the container space. Docker have also done an incredibly good job of making docker easy to use and to try out.

By contrast, CoreOS and Kubernetes are not tools for beginners. You don’t really need them until you get code in production and suffer from the problems they solve, while Docker is something you can play around with locally. Docker’s ease of use, everything from the command line to the well thought out docs to boot2docker, are also well ahead of rkt and and CoreOS’s offering - which are much harder to get started with.

How does this play out?

If you’re a consumer in this space, looking to deploy production containers soon, this isn’t a particularly helpful war. The ecosystem is very young, people shipping containers in production are few and far between, and a little bit of maturing of the components would have been useful before the war emerged. We are going to end up with a multitude of different ways to do things, and it’s clear we’re far from having one true way.

From a business perspective, it’s difficult for any of the players to capitulate on their directions. Docker is certainly focusing on building the Docker ecosystem, to the exclusion of everyone else. Unfortunately, they don’t have all the pieces yet.

Other companies who want to play in the ecosystem are unlikely to be pleased by Docker’s positioning. CoreOS certainly isn’t alone in their desire for a more open ecosystem.

Ironically, Docker came about due to a closed ecosystem with a single dominant player. Heroku dominates the PaaS ecosystem to the extent that there really isn’t a PaaS ecosystem, just Heroku. Dotcloud failed to make inroads, and so opened its platform up to disrupt Heroku’s position and move things in a different direction such that Heroku’s dominance didn’t matter. In Docker, they certainly appear to have succeeded with that. Now that Docker is the dominant player is the disruptive ecosystem, CoreOS and other players will want to unseat them and fight on a level playing field before things settle too much.

The risk for Docker is that on this trajectory, if they lose the war they risk losing everything. If nobody else can play in this space, all of the companies that are left outside will build their own ecosystem that leaves Docker on the outside. Given that Docker lacks considerable parts of the ecosystem (mature orchestration being an obvious one), their attempts at owning the ecosystem are unlikely to succeed in the near term.

Meanwhile, CoreOS will need to replicate the approachability of the Docker toolset to compete effectively, and will need to do so before Docker solves the missing parts of its puzzle.

All of the other companies are sitting neutral right now. Google, MS, VMware are all avoiding committing one way or the other. Their motivations are typically clear, and it doesn’t benefit any of them to pick one or the other. The exception here is that the open ACI standard is likely to interest VMware at least, but I wouldn’t be surprised to see Google doing something in this space, too.

There is massive risk for all of the players in the ecosystem, depending on how this plays out. Existing players like Amazon, Google and Microsoft are providing differentiated services and tools around containers. The risk of not doing so, of owning no piece of the puzzle, is being sidelined and eventual commoditization. The one API that abstracts over the other tools is the one which wins.

Long story short - this is the start of a war that will probably be quite bloody, and that none of us is going to enjoy.

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