Defining a Zero-Downtime Deployment

Updating a single-replica MongoDB cannot demonstrate true power behind Deployments. We need a scalable Service. It’s not that MongoDB cannot be scaled (it can), but it’s not as straightforward as an application that was designed to be scalable. We’ll jump to the second application in the stack and create a Deployment of the ReplicaSet that will create Pods based on the go-demo-2 image.

Note: Zero-downtime Deployment is a prerequisite for higher frequency releases.

Looking into the definition

Let’s take a look at the Deployment definition of the API go-demo-api.