(I'll do some necromancy on this question as this was the most relevant StackOverflow question I found while searching for a solution to this as it is no longer possible to do this through the classic portal)
Disclaimer: Microsoft has seemingly removed support for logging to Table in the Azure Portal, so I don't know if this is deprecated or will soon be deprecated, but I have a solution that will work now (31.03.2017):
There are specific settings determining logging, I first found out information on this from an issue in the Azure Powershell github: https://github.com/Azure/azure-powershell/issues/317
The specific settings we need are (from github):
AzureTableTraceEnabled = True, & AppSettings has:
DIAGNOSTICS_AZURETABLESASURL
Using the excellent resource explorer (https://resources.azure.com) under (GUI navigation):
/subscriptions/{subscriptionName}/resourceGroups/{resourceGroupName}/providers/Microsoft.Web/sites/{siteName}/config/logs
I was able to find the Setting AzureTableTraceEnabled in the Properties.
The property AzureTableTraceEnabled has Level and sasURL. In my experience updating these two values (Level="Verbose",sasUrl="someSASurl") will work, as updating the sasURL sets DIAGNOSTICS_AZURETABLESASURL in appsettings.
How do we change this? I did it in Powershell. I first tried the cmdlet Get-AzureRmWebApp, but could not find what i wanted - the old Get-AzureWebSite does display AzureTableTraceEnabled, but I could not get it to update (perhaps someone with more powershell\azure experience can come with input on how to use the ASM cmdlets to do this).
The solution that worked for me was setting the property through the Set-AzureRmResource command, with the following settings:
Set-AzureRmResource -PropertyObject $PropertiesObject -ResourceGroupName "$ResourceGroupName" -ResourceType Microsoft.Web/sites/config -ResourceName "$ResourceName/logs" -ApiVersion 2015-08-01 -Force
Where the $PropertiesObject looks like this:
$PropertiesObject = @{applicationLogs=@{azureTableStorage=@{level="$Level";sasUrl="$SASUrl"}}}
The Level corresponds to "Error", "Warning", "Information", "Verbose" and "Off".
It is also possible to do this in the ARM Template (important bits is in properties on the logs resource in the site):
{
"apiVersion": "2015-08-01",
"name": "[variables('webSiteName')]",
"type": "Microsoft.Web/sites",
"location": "[resourceGroup().location]",
"tags": {
"displayName": "WebApp"
},
"dependsOn": [
"[resourceId('Microsoft.Web/serverfarms/', variables('hostingPlanName'))]"
],
"properties": {
"name": "[variables('webSiteName')]",
"serverFarmId": "[resourceId('Microsoft.Web/serverfarms', variables('hostingPlanName'))]"
},
"resources": [
{
"name": "logs",
"type": "config",
"apiVersion": "2015-08-01",
"dependsOn": [
"[resourceId('Microsoft.Web/sites/', variables('webSiteName'))]"
],
"tags": {
"displayName": "LogSettings"
},
"properties": {
"azureTableStorage": {
"level": "Verbose",
"sasUrl": "SASURL"
}
}
}
}
The issue with doing it in ARM is that I've yet to find a way to generate the correct SAS, it is possible to fetch out Azure Storage Account keys (from: ARM - How can I get the access key from a storage account to use in AppSettings later in the template?):
"properties": {
"type": "AzureStorage",
"typeProperties": {
"connectionString": "[concat('DefaultEndpointsProtocol=https;AccountName=', variables('storageAccountName'),';AccountKey=',listKeys(resourceId('Microsoft.Storage/storageAccounts', variables('storageAccountName')), providers('Microsoft.Storage', 'storageAccounts').apiVersions[0]).keys[0].value)]"
}
}
There are also some clever ways of generating them using linked templates (from: http://wp.sjkp.dk/service-bus-arm-templates/).
The current solution I went for (time constraints) was a custom Powershell script that looks something like this:
...
$SASUrl = New-AzureStorageTableSASToken -Name $LogTable -Permission $Permissions -Context $StorageContext -StartTime $StartTime -ExpiryTime $ExpiryTime -FullUri
$PropertiesObject = @{applicationLogs=@{azureTableStorage=@{level="$Level";sasUrl="$SASUrl"}}}
Set-AzureRmResource -PropertyObject $PropertiesObject -ResourceGroupName "$ResourceGroupName" -ResourceType Microsoft.Web/sites/config -ResourceName "$ResourceName/logs" -ApiVersion 2015-08-01 -Force
...
This is quite an ugly solution, as it is something extra you need to maintain in addition to the ARM template - but it is easy, fast and it works while we wait for updates to the ARM Templates (or for someone cleverer than I to come and enlighten us).
