The arrival of Docker and its container technology is causing a stir in the IT world. Accompanied by effective marketing and emblematic adoption cases such as Netflix and Spotify, many operators are pitting this technology against virtualisation. This opposition is more about creating buzz than reality.
In the IT sector, it's fashionable to present new techniques as the solution to all ills, and in return to send more mature technologies back to the drawing board. Docker (formerly DotCloud) is no exception. According to some proponents, this container technology would make traditional virtualisation obsolete.
"This model does not replace the other, but the use case will dictate the use of one or the other", explains Julien Cyr, pre-sales engineer for Intrinsec and Docker specialist.
Docker, for rapid development
In fact, the attraction of Docker is based on two assets: a standard and ease of development. To explain this technology simply, we need to think of Docker as a set of containers that can be used to assemble each block of the application under development like Lego.
As Julien Cyr explains, "Developers often work on their own PC with their own configuration. But as they go through testing, acceptance, deployment and production on other servers in the cloud, both private and public, the configurations may be different. The application will then react differently, and you may experience functional regressions. With containers, each part of the application is in a container. Because it's standard, the environment will be identical on any platform, which saves precious time in development projects. "
To put it in more technical terms, integration and continuous deployment (CI/CD) are Docker's two key assets, to which should be added scalability management. These are all advantages that are well understood by businesses that need to deploy new services quickly and manage high levels of scalability. It's no coincidence that web-focused companies such as Netflix and Spotify have turned to Docker to design their platforms.
Standard virtualisation for mission-critical systems
However, Docker is not suitable for every use case.
As Julien Cyr sums up, "web-oriented applications are generally suited to Docker, while legacy applications can only be run on standard virtual machines (VMware, Xen etc.). "
The division between the two technologies is fairly clear. The company's critical and structuring applications - ERP, Oracle and others - are optimised to run on this type of virtual machine, which offers numerous advantages in terms of administration, security and pooling. Just like performance.
Docker and virtual machines: two essential technical worlds
In short, when it comes to deploying infrastructure and operating information systems, traditional virtual machines are indestructible and irreplaceable. On the other hand, new web applications will be designed using containers under the pressure of the agility and speed demanded by time-to-market. In other words, the future of this technology looks bright, but so does the future of virtual machines.