Docker offers a new, lightweight approach to application portability. Applications are shipped using a common container format, and managed with a high-level API. Their processes run within isolated namespaces which abstract the operating environment, independently of the distribution, versions, network setup, and other details of this environment.

This “containerization” has often been nicknamed “the new virtualization”. But containers are more than lightweight virtual machines. Beyond their smaller footprint, shorter boot times, and higher consolidation factors, they also bring a lot of new features and use cases which were not possible with classical virtual machines.

We will focus on one of those features: separation of operational concerns. Specifically, we will demonstrate how some fundamental tasks like logging, remote access, backups, and troubleshooting can be entirely decoupled from the deployment of applications and services. This decoupling results in independent, smaller, simpler moving parts; just like microservice architectures break down large monolithic apps in more manageable components.