kops: kops toolbox template: Incorrect interpolation of arrays from values yaml

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

Version 1.11.0

2. What commands did you run? What is the simplest way to reproduce this issue?

kops toolbox template --values values.yaml --template def.yaml

def.yaml:

apiVersion: kops/v1alpha2
kind: Cluster
spec:
  kubernetesApiAccess: {{.allowedIPs}}

values.yaml:

allowedIPs:
- 1.2.3.4/32
- 4.3.2.1/32

3. What happened after the commands executed?

apiVersion: kops/v1alpha2
kind: Cluster
spec:
  kubernetesApiAccess: [1.2.3.4/32 4.3.2.1/32]

4. What did you expect to happen?

The interpolated array in the resulting yaml should contain commas to make it a proper yaml array. The way that it’s outputting the array in the interpolated outputted yaml is incorrect.

5. Any other information?

This also happens when using the --set or --set-string flag with an array as documented in HERE, making the documentation incorrect due to this bug.