A critical part of deploying containers within a Kubernetes cluster is understanding how they use the network. In previous posts we’ve deployed pods and services and were able to access them from a client such as a laptop, but how did that work exactly? I mean, we had a bunch of ports configured in our manifest files, so what do they mean? And what do we do if we have more than one pod that wants to use the same port like 443 for https? ...
If you’ve been following the series, you may be thinking that we’ve built ourselves a problem. You’ll recall that we’ve now learned about Deployments so that we can roll out new pods when we do upgrades, and replica sets can spin up new pods when one dies. Sounds great, but remember that each of those containers has a different IP address. Now, I know we haven’t accessed any of those pods yet, but you can imagine that it would be a real pain to have to go lookup an IP Address every time a pod was replaced, wouldn’t it? This post covers Kubernetes Services and how they are used to address this problem, and at the end of this post, we’ll access one of our pods … finally. ...