Deploying ARM template with 2 hostnamebindings returns conflict error can't modify because another operation is in progress - json

Question

I am trying to deploy an ARM template through Azure DevOps. I've tried doing a test deployment (Test-AzResourceGroupDeployment) through PowerShell without any issues.
This issue has persisted for several weeks, and i've read some posts stating it dissapeared after a few hours or after a day, however this has not been the case for me.
In Azure DevOps my build is succeeding just fine. But when i try to create a release through my release pipeline using the resource "Azure resource group deployment" it will fail stating the error:
"Code": "Conflict",
"Message": "Cannot modify this site because another operation is in progress. Details: Id: 4f18af87-8848-4df5-82f0-ec6be47fb599, OperationName: Update, CreatedTime: 9/27/2019 8:55:26 AM, RequestId: 691b5183-aa8b-4a38-8891-36906a5e2d20, EntityType: 3"
Update
I have later noticed that the error surfaces when trying to deploy my hostNameBindings for the site.
I have 2 different hostNameBindings in my template which causes the failure.
It fails apparently because it tries to deploy both of them at the same time, though i am not aware of an apparent fix for this so any help would still be appreciated!
I tried to use the copy function but as far as i know that will make an exact copy for both hostNameBindings which is not what i need. first of all they have different names and properties, anyone got a fix for this?

Answer 1

Make the one hostNameBindings depend on the other host name binding. Then they will be executed 1 after another and you should not get the same error message.
"dependsOn": [
"[resourceId('Microsoft.Web/sites/', variables('websitename'))]",
"[resourceId('Microsoft.Web/sites/hostNameBindings/',variables('websitename'), variables('firstbindingame-aftertheslash-sowithoutthewebsitename'))]"
],

Answer 2

Look like people already notice this issue and trying to fix it.
https://status.azure.com/

Answer 3

I had the same issue when using the Copy function in order to add multiple Custom Domains. Thanks to David Gnanasekaran's blog I was able to fix this issue.
By default the copy function will execute in parallel. By setting the mode to serial and setting the batchSize to 1 I did not receive any operation is in progress errors.
Here is my piece of ARM template to set the custom domains.
"copy": {
"name": "hostNameBindingsCopy",
"count": "[length(parameters('customDomainNames'))]",
"mode": "Serial",
"batchSize": 1
},
"apiVersion": "[variables('webApiVersion')]",
"name": "[concat(variables('webAppName'), '/', parameters('customDomainNames')[copyIndex()])]",
"type": "Microsoft.Web/sites/hostNameBindings",
"kind": "string",
"location": "[resourceGroup().location]",
"condition": "[greater(length(parameters('customDomainNames')), 0)]",
"dependsOn": [
"[resourceId('Microsoft.Web/sites', variables('webAppName'))]"
],
"properties": {
"customHostNameDnsRecordType": "CName",
"hostNameType": "Verified",
"siteName": "parameters('webAppName')"
}