Question
I wanted to know what is the difference between a Replication Controller and a Deployment within Kubernetes (1.2). Going through the getting started document (http://kubernetes.io/docs/hellonode/) I have created a deployment - but it doesn't show up on the web UI.
When I create apps from the web UI - they are created as replication controllers. Functionally though, they seem very similar (they both manage pods and have services).
So - what is the difference and when should I use each?
Answer
Deployments are a newer and higher level concept than Replication Controllers. They manage the deployment of Replica Sets (also a newer concept, but pretty much equivalent to Replication Controllers), and allow for easy updating of a Replica Set as well as the ability to roll back to a previous deployment.
Previously this would have to be done with kubectl rolling-update which was
not declarative and did not provide the rollback features.
~~Kubernetes Dashboard has not yet been updated to support Deployments, and currently only supports Replication Controllers (see[Deployments not visible in Kubernetes Dashboard](https://stackoverflow.com/questions/37305133/deployments-not- visible-in-kubernetes-dashboard/37305814#37305814)).~~
EDIT: The dashboard now supports Deployments.
