In the earlier chapters, we laid down a strong foundation on the need for container networking, how to run a service inside a Docker container, and how to expose this service to the outside world by opening up network ports and other prerequisites. However, recently, there are advanced mechanisms being made available and a few third-party orchestration platforms hitting the market for sagaciously establishing dynamic and decisive linkages between distributed and differently-enabled containers in order to compose powerful containers for comprehensively, yet compactly containing process-centric, multi-tiered, and enterprise-class distributed applications. In the extremely diversified yet connected world, the concept of orchestration cannot be kept away from the deserved prominence for long. This chapter is precisely allocated for explaining the nitty-gritty of container orchestration, and its direct role is in picking up discrete containers to systematically compose sophisticated containers that are more directly aligned with the varying business expectations and expediencies.

In this chapter, we will discuss the following topics in detail:

• Linking containers
• Orchestrating containers
• Orchestrating containers using the docker-compose tool

As mission-critical applications are overwhelmingly being built through loosely coupled, yet highly cohesive components/services destined to run on geographically-distributed IT infrastructures and platforms, the concept of composition is getting a lot of attention and attraction. For sustaining the well-begun containerization journey, the orchestration of containers is being prescribed as one of the most critical and crucial requirements in the ensuing, instant-on, adaptive, and smart IT era. There are a few proven and promising methods and standards-compliant tools for enabling the enigmatic orchestration goals.