OS specified in parameters file not being deployed

[janegilring]

Describe the bug
When deploying a RHEL BYOS image from a private marketplace offering, the actual OS deployed is not the one specified in the parameters file.

To Reproduce
Steps to reproduce the behavior:

1. Define the following OS settings in the parameters file:
   "osImageType": {
   "value": "marketplace"
   },
   "value": {
   "publisher": "redhat",
   "offer": "rhel-byos",
   "sku": "rhel-lvm76",
   "version": "latest"
   }

2. Check OS version in virtual machine after VM deployment has completed, in our case the deployed OS is RHEL 7.7 raw.

Expected behavior
The deployed OS should be as specified in the parameters file.

Template Information (please complete the following information):

• OS: rhel-lvm76
• Branch: [master]

Additional context
When looking at the Inputs for the VM deployments in the target resource group, the following Input parameters is relevant for this issue:

• osImageType: marketplace

• marketplaceOsImage: {"publisher":"redhat","offer":"rhel-byos","sku":"rhel-lvm76","version":"7.6.20190918"}

• imageReference: {"publisher":"RedHat","offer":"RHEL","sku":"7-RAW","version":"latest"}

[haroldwongms]

If you look at the nested templates used to create the VMs, the three mentioned parameters are passed in. There is a condition when osImageType=marketplace, marketplaceOsImage is used otherwise imageReference is used.

Don't check the OS version within the VM, look at resources.azure.com to determine the image used for the VM. The prep scripts perform a yum update so ultimately, the OS version should be identical regardless.

[janegilring]

I see, however, here is an example from a deployment where the following properties is defined in the parameters file:
"osImageType": {
"value": "marketplace"
},
"marketplaceOsImage": {
"value": {
"publisher": "redhat",
"offer": "rhel-byos",
"sku": "rhel-lvm76",
"version": "7.6.20190918"
}
}

The imageReference property is not defined.

In the deployed instance, when looking at the bastion VM as an example, we see the following in it's properties on https://resources.azure.com:
"storageProfile": {
"imageReference": {
"publisher": "redhat",
"offer": "rhel-byos",
"sku": "rhel-lvm76",
"version": "7.6.20190918"
},
"osDisk": {
"osType": "Linux",
"name": "ocpclustertest-infra01-osdisk",
"createOption": "FromImage",

However, when SSH' ing into the VM the output from hostnamectl indicates the OS version being 7.7:
Static hostname: ocpclustertest-bastion
Icon name: computer-vm
Chassis: vm
Machine ID: cef2ff62b1da4edb8ce8b4b26b865a2d
Boot ID: b4856b5b4b3241759baf1921095e520e
Virtualization: microsoft
Operating System: OpenShift Enterprise
CPE OS Name: cpe:/o:redhat:enterprise_linux:7.7:GA:server
Kernel: Linux 3.10.0-957.27.4.el7.x86_64
Architecture: x86-64

Could the issue be that imageReference has a default value in azuredeploy.json, hence that overrides the marketplaceOsImage specified in the parameters file?