kops: Instance groups stuck in "NeedsUpdate"

1. What kops version are you running? The command kops version, will display this information. 1.12.1

2. What Kubernetes version are you running? kubectl version will print the version if a cluster is running or provide the Kubernetes version specified as a kops flag. v1.12.7

3. What cloud provider are you using? aws

4. What commands did you run? What is the simplest way to reproduce this issue? After running kops rolling-update, my instance groups are still reporting “NeedsUpdate”. I don’t understand this, since nodes are literally 5 minutes old. How can I see “why” kops things they need update? I’ve tried looking at the documentation for rolling-update parameters but the documentation isn’t really clear about what flags are available or what they do. So I guess my bug is: I don’t understand why kops reports NeedsUpdate for my nodes, and I don’t understand how I can figure out why.

5. What happened after the commands executed? Instance Groups are still reporting NeedsUpdate.

6. What did you expect to happen? Instance Groups should report Ready since they just got rolling-updated.