Microsoft.Web/sites and sites/slots noisy property defaults.

[woodylaurence]

Describe the noise

When deploying a simple app service plan/app service/app service slot setup, and then immediately running a what-if with the same template, there seems to be a lot of noise around default property values.

Resource type
Microsoft.Web/sites and Microsoft.Web/sites/slots

apiVersion
2020-09-01 and 2020-06-01 tested, both have same issue

Client
Azure CLI

Relevant ARM Template code (we only need the resource object for the above resourceType and apiVersion, but if it's easier you can include the entire template

{
  "$schema": "https://schema.management.azure.com/schemas/2019-04-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.0",
  "functions": [],
  "resources": [
    {
      "type": "Microsoft.Web/serverfarms",
      "apiVersion": "2020-09-01",
      "name": "deploymentSlotTestPlan",
      "location": "UK South",
      "properties": {
        "maximumElasticWorkerCount": 0,
        "isSpot": false
      },
      "sku": {
        "name": "S1",
        "capacity": 1
      }
    },
    {
      "type": "Microsoft.Web/sites",
      "apiVersion": "2020-09-01",
      "name": "deploymentSlotTest",
      "location": "UK South",
      "properties": {
        "serverFarmId": "[resourceId('Microsoft.Web/serverfarms', 'deploymentSlotTestPlan')]"
      },
      "dependsOn": [
        "[resourceId('Microsoft.Web/serverfarms', 'deploymentSlotTestPlan')]"
      ]
    },
    {
      "type": "Microsoft.Web/sites/slots",
      "apiVersion": "2020-09-01",
      "name": "deploymentSlotTest/slot",
      "location": "UK South",
      "properties": {
        "serverFarmId": "[resourceId('Microsoft.Web/serverfarms', 'deploymentSlotTestPlan')]"
      },
      "dependsOn": [
        "[resourceId('Microsoft.Web/serverfarms', 'deploymentSlotTestPlan')]"
      ]
    }
  ]
}

Expected response
Doing what-if on the same template that was just deployed should produce no noise.

Current (noisy) response

~ Microsoft.Web/sites/deploymentSlotTest [2020-09-01]
    + properties.siteConfig.http20Enabled:       true
    + properties.siteConfig.localMySqlEnabled:   false
    + properties.siteConfig.netFrameworkVersion: "v4.6"

  ~ Microsoft.Web/sites/deploymentSlotTest/slots/slot [2020-09-01]
    - kind:                                              "app"
    - properties.adminEnabled:                           true
    - properties.clientAffinityEnabled:                  true
    - properties.clientCertEnabled:                      false
    - properties.clientCertMode:                         "Required"
    - properties.containerSize:                          0
    - properties.customDomainVerificationId:             <<Redacted>>
    - properties.deploymentId:                           "deploymentSlotTest__3f6d"
    - properties.eligibleLogCategories:                  "AppServiceAppLogs,AppServiceAuditLogs,AppServiceConsoleLogs,AppServiceHTTPLogs,AppServiceIPSecAuditLogs,AppServicePlatformLogs,ScanLogs"
    - properties.ftpUsername:                            "deploymentSlotTest__slot\$deploymentSlotTest__slot"
    - properties.ftpsHostName:                           <<Redacted>>
    - properties.homeStamp:                              <<Redacted>>
    - properties.hostNameSslStates: [
        0:

          hostType:        "Standard"
          ipBasedSslState: "NotConfigured"
          name:            "deploymentslottest-slot.azurewebsites.net"
          sslState:        "Disabled"

        1:

          hostType:        "Repository"
          ipBasedSslState: "NotConfigured"
          name:            "deploymentslottest-slot.scm.azurewebsites.net"
          sslState:        "Disabled"

      ]
    - properties.httpsOnly:                              false
    - properties.inboundIpAddress:                       <<Redacted>>
    - properties.kind:                                   "app"
    - properties.name:                                   "deploymentSlotTest(slot)"
    - properties.possibleInboundIpAddresses:            <<Redacted>>
    - properties.redundancyMode:                         "None"
    - properties.selfLink:                               <<Redacted>>
    - properties.siteConfig.acrUseManagedIdentityCreds:  false
    - properties.siteConfig.minimumElasticInstanceCount: 0
    - properties.siteDisabledReason:                     0
    - properties.siteProperties:

        properties: [
          0:

            name: "LinuxFxVersion"

          1:

            name: "WindowsFxVersion"

        ]

    - properties.sku:                                    "Standard"
    - properties.storageAccountRequired:                 false
    - properties.storageRecoveryDefaultState:            "Running"
    - properties.tags:

        Environment: "test"

    - properties.webSpace:                               "rg-deployment-slot-test-UKSouthwebspace"
    + properties.siteConfig.http20Enabled:               true
    + properties.siteConfig.localMySqlEnabled:           false
    + properties.siteConfig.netFrameworkVersion:         "v4.6"

Additional context
I created this simple scenario to test another issue we had were a larger deployment was being run including app service and deployment slots and changes to the slot's properties were being completely ignored by what-if, couldn't seem to replicate in this simple scenario, but wondered whether the issues could be linked in some way.

[woodylaurence]

As a follow-up, I'm fairly sure that the issue mentioned above about changes to slot properties being ignored is down to #157 .

The noise mentioned still stands though and is unaccounted for, as for as I'm aware.