Services

We’ve just learned that Pods are mortal and can die. However, if they’re managed via Deployments or DaemonSets, they get replaced when they fail. But replacements come with totally different IP addresses. This also happens when you perform scaling operations – scaling up adds new Pods with new IP addresses, whereas scaling down takes existing Pods away. Events like these cause a lot of IP churn.

The point I’m making is that Pods are unreliable, which poses a challenge. Assume you’ve got a microservices app with a bunch of Pods performing video rendering. How will this work if other parts of the app that need to use the rendering service cannot rely on the rendering Pods being there when they need them?

This is where Services come into play. Services provide reliable networking for a set of Pods.