Pre Provision Extensions not working on windows nodes

[adelina-t]

Using preProvision Extensions will not work on k8s clusters with windows nodes.

Acs-engine version: tested with versions > v.0.18.0

The method here:

acs-engine/pkg/acsengine/template_generator.go

Line 553 in f620260

"GetKubernetesAgentPreprovisionYaml": func(profile *api.AgentPoolProfile) string {

that is responsible for generating the preprovision extension command never gets called in the templates for windows agents.

A quick solution for this would be having a placeholder in the deployment script for Windows that would be replaced with the extension command, like in the case of DCOS (

acs-engine/parts/dcos/dcosWindowsProvision.ps1

Line 205 in 0d35dd6

PREPROVISION_EXTENSION

)