Azure Web App staging slot App Settings missing on ARM template deployment

Question

I am working on ARM templates for some web application deployments. These templates set up a web application along with a staging slot for this application. The way I wish to handle this is to only deploy the app settings to the staging slot. By doing this I can handle rollbacks nicely as the app settings will swap with the slot and have any old values tied to the app they were deployed with. However upon deploying these ARM templates successfully I can see there are no app settings deployed to my staging slots other than website_node_default_version.

Below is a snippet of the ARM templates showing one pair of web app + staging slot:

{
        "type": "Microsoft.Web/sites",
        "apiVersion": "2016-08-01",
        "name": "[variables('egressAppName')]",
        "location": "[parameters('location')]",
        "kind": "app",
        "properties": {
            "enabled": true,
            "serverFarmId": "[resourceId('Microsoft.Web/serverfarms', variables('appServicePlanName'))]",
            "clientAffinityEnabled": true
        }
    },
    {
        "type": "Microsoft.Web/sites/slots",
        "apiVersion": "2016-08-01",
        "name": "[concat(variables('egressAppName'),'/','staging')]",
        "location": "[parameters('location')]",
        "dependsOn": [
            "[resourceId('Microsoft.Web/sites', variables('egressAppName'))]"
        ],
        "kind": "app",
        "properties": {
            "enabled": true,
            "serverFarmId": "[resourceId('Microsoft.Web/serverfarms', variables('appServicePlanName'))]",
            "clientAffinityEnabled": true,
            "appSettings": [
                {
                    "name": "APP_INSIGHTS_INSTRUMENTATION_KEY",
                    "value": "[reference(resourceId(variables('rsg') ,'microsoft.insights/components/', variables('ainName')), '2015-05-01').InstrumentationKey]"
                },
                {
                    "name": "ASPNETCORE_ENVIRONMENT",
                    "value": "[parameters('netCoreEnvironment')]"
                },
                {
                    "name": "MONITOR_API_ACCOUNT_RATE_LIMIT",
                    "value": "[parameters('accountRateLimit')]"
                },
                {
                    "name": "MONITOR_API_ACCOUNT_RATE_LIMIT_WINDOW_SECONDS",
                    "value": "[parameters('accountLimitWindow')]"
                },
                {
                    "name": "MONITOR_API_IP_RATE_LIMIT",
                    "value": "[parameters('ipLimit')]"
                },
                {
                    "name": "MONITOR_API_IP_RATE_LIMIT_WINDOW_SECONDS",
                    "value": "[parameters('ipLimitWindow')]"
                },
                {
                    "name": "MONITOR_DATA_EXPLORER_INSTANCE_NAME",
                    "value": "[variables('dataExplorerName')]"
                },
                {
                    "name": "MONITOR_DATA_EXPLORER_REGION",
                    "value": "[parameters('location')]"
                },
                {
                    "name": "MONITOR_DIAG_ACCOUNT_APP_ID",
                    "value": "[parameters('diagAccountAppID')]"
                },
                {
                    "name": "MONITOR_DIAG_ACCOUNT_APP_SECRET_LOCATION",
                    "value": "[parameters('diagAccountAppSecret')]"
                },
                {
                    "name": "MONITOR_EGRESS_APP_TENANT",
                    "value": "[parameters('egressTenantID')]"
                },
                {
                    "name": "MONITOR_KEY_VAULT_APP_ID",
                    "value": "[parameters('keyVaultAppID')]"
                },
                {
                    "name": "MONITOR_KEY_VAULT_APP_SECRET",
                    "value": "[parameters('keyVaultAppSecret')]"
                },
                {
                    "name": "MONITOR_KEY_VAULT_NAME",
                    "value": "[variables('keyVaultName')]"
                },
                {
                    "name": "MONITOR_PGSQL_CONNECTION_STRING",
                    "value": "[parameters('postgresConnectionString')]"
                },
                {
                    "name": "MONITOR_TOKEN_VALIDATION_CLOCK_SKEW_SECONDS",
                    "value": "[parameters('validationClockSkew')]"
                },
                {
                    "name": "WEBSITE_RUN_FROM_PACKAGE",
                    "value": "1"
                }
            ]
        }
    }

I have tried deleting just the staging slots and redeploying as well as deleting all the web apps and redeploying with no luck. At this point I'm just hoping to get more eyes over this to see if I've missed anything obvious. I'm deploying these ARM templates through Azure DevOps release pipelines using the Azure Resource Group Deployment task.

Answer 1

The appSettings should be defined in the SiteConfig object instead of Microsoft.Web/sites/slots properties as your template. To create a Microsoft.Web/sites/slots/config resource for app settings, you could add the JSON to the resources section of your template.

Also, you can see the Monitoring and diagnostic settings could be swapped here.