Deis combines Docker and CoreOS

Container Ship

The Aim: Web Applications

Deis application examples [15] almost always involve different web applications, and you will come to grips with "different language environments" quickly, explain the creators: A Deis container usually involves a process instruction through which Deis learns what type of container should be used.

However, Deis is not particularly well equipped architecturally when the task is not directly about applications but rather frameworks. Nothing prevents users from building their own apps for development environments, but you won't find many corresponding examples off the shelf.

Docker or Rocket?

Anyone who wants to try Deis should ideally do so in VMs and should expect a few hours work for installation and deployment. The components connected with Deis will likely require special attention.

A recent development that could be significant for the future of Deis is that CoreOS finally broke from Docker in December 2014 [18] and presented its own container technology called Rocket [19]. Of course, the CoreOS developers promise that everything about Rocket will improve.

Against this background, the interesting question is whether Deis will get enthusiastic about Rocket or continue to use Docker as long as it is still available in CoreOS.

At the same time, other projects are waiting in the wings to take up the race against Deis. For example, Solum (Figure 5), like Deis, wants to make PaaS available with a mouse click. Unlike Deis, Solum [20] integrates almost seamlessly with OpenStack (see the "Deis and OpenStack" box).

Deis and OpenStack

OpenStack and Deis both use a separate database for metadata (e.g., information on existing VMs). Each has a separate network component – in OpenStack, the network component is called Neutron; in Deis, it is called the router. The router in Deis is undoubtedly much less complex than OpenStack's equivalent.

The additional complexity of Neutron reflects the fact that OpenStack is designed for mass production. It remains to be seen how a Deis cluster will perform if the administrator subjects it to hundreds of thousands of simultaneous HTTP requests that end up on dozens of computing nodes.

In many corners, the impression arises that, for better or worse, Deis developers wanted to reinvent the cloud. In fact, it is not possible to integrate Deis meaningfully with another cloud solution. Anyone already operating an OpenStack cloud cannot simply connect Deis. Usually, this would mean acquiring separate hardware. However, the operation of two competing platforms is a death sentence for efficient IT management.

This amount of overhead is probably too high for many companies, and the benefits arising from efficient PaaS with Deis and Docker do not outweigh this disadvantage. Anyone who is not solely active in the PaaS environment is unlikely to be happy with Deis alone.

Figure 5: With Solum, a successor for Deis is already rising in the rapidly changing container market.

The container market remains unsettled and erratic, and the remaining solutions have yet to emerge. It is difficult to predict whether Deis will be one of the winners, but for now, it sets the technical standard in many ways and irons out some of Docker's biggest problems.

However, issues such as the missing user interface and lack of integration into other environments are real problems. At least for now, the race across the Linux ocean is not yet over for these container ships.

Infos