Get Function & Host Keys of Azure Function In Powershell

I got it working by using the following:

    "outputs": {
    "FunctionAppName": {
        "type": "string",
        "value": "[parameters('functionName')]"
    },
    "Key": {
        "type": "string",
        "value": "[listsecrets(resourceId('Microsoft.Web/sites/functions', parameters('existingFunctionAppName'), parameters('functionName')),'2015-08-01').key]"
    },        
    "Url": {
        "type": "string",
        "value": "[listsecrets(resourceId('Microsoft.Web/sites/functions', parameters('existingFunctionAppName'), parameters('functionName')),'2015-08-01').trigger_url]"
    }        
}

I couldn't find any examples either. But by using the above, a quickstart sample at GitHub and the documentation of resource functions along with a some trial and error, I got it to out.

Please note the variables/parameters and names have been changed.

Question doesn't seem to be answered as it was requesting to get the Function key from Powershell and not ARM templates. I'm using the script below to get the function key from Powershell in Azure DevOps.

$accountInfo = az account show
$accountInfoObject = $accountInfo | ConvertFrom-Json
$subscriptionId  = $accountInfoObject.id

$resourceGroup = "your-resource-group"
$functionName = "your-function-name"

$functionkeylist = az rest --method post --uri "https://management.azure.com/subscriptions/$subscriptionId/resourceGroups/$resourceGroup/providers/Microsoft.Web/sites/$functionName/host/default/listKeys?api-version=2018-11-01"
$keylistobject = $functionkeylist | ConvertFrom-Json
$functionKey = $keylistobject.functionKeys.default

Hope this helps.

I could not get the accepted answer to work to retrieve the default host key. @4c74356b41's answer is very close. You can get the keys out using the code below. The default host key will be in Outputs.functionKeys.Value.functionKeys.default.Value.

  "outputs": {
    "functionKeys": {
      "type": "object",
      "value": "[listkeys(concat(resourceId('Microsoft.Web/sites', variables('functionAppName')), '/host/default'), '2018-11-01')]"
    }
  }