Motivation
Some companies are already trying to transition their services from traditional VMs in the cloud or other container orchestration tools (for example, AWS ECS, Azure CI, and so on) to K8s clusters. One of the biggest problems though in moving to K8s is how we can set up more sophisticated deployment strategies, as the standard rolling updates provided for free by K8s would not work in some cases. For example, what if I want to deploy a new version of a service but I want to first test that it’s functional and then switch to the new version and, in parallel, destroy the old one? This is called blue/green deployment and can give me the power to reduce downtime and not even impact my end users.
In the next section, we will see how we can achieve this in K8s using only the K8s objects and how we can deploy a service with blue/green deployment.
Simple blue-green in K8s
I have created a small Golang app that serves a simple HTTP server and returns the version of...
