rhel.json

    {
        "type": "Microsoft.VirtualMachineImages/imageTemplates",
        "name": "RHEL75",
        "apiVersion": "2019-05-01-preview",
        "location": "westus",
        "properties": {
                "source": {
                "type": "ISO",
                "sourceURI": "[uri-to-blob-with-sas]",
                "sha256Checksum": "d0dd6ae5e001fb050dafefdfd871e7e648b147fb2d35f0e106e0b34a0163e8f5"
                
            },
            "customize": [
                {
                    "type": "Shell",
                    "name": "InstallUpgrades",
                    "inline": [
                        "sudo subscription-manager register --force --org=[rh-org] --activationkey=[rh-key]",
                        "sudo yum -y update",
                        "sudo subscription-manager unregister",
                        "sudo systemctl disable firewalld"
                        ]
                }

            ],
            "distribute": 
                [
                    {   "type":"ManagedImage",
                        "imageId": "/subscriptions/[subs]/resourceGroups/[resourcegrouo]/providers/Microsoft.Compute/images/[image]",
                        "location": "westeurope",
                        "runOutputName": "[image]",
                        "artifactTags": {
                            "source": "azVmImageBuilder",
                            "baseosimg": "rhel75"
                        }
                    }

                ]

        }
    }