How to add a default function key with ARM template for a deployment slot in Azure Functions

Question

I want to add a default function key to my deployment slot in azure. Therefore I've added it to my template like this:

...,
{
   "type": "Microsoft.Web/sites/slots/functions/keys",
   "dependsOn":[
     "[resourceId('Microsoft.Web/sites/slots', variables('apiServiceName'),'deploy')]"
   ],
   "apiVersion": "2018-02-01",
   "name": "[concat(variables('apiServiceName'),'/deploy/default/eventgrid')]",
   "properties": {
       "name": "eventgrid"
   }
},...

Unfortunately, I cannot find how to get it to work, this is the closest I can find to not have the template fail (fewer segments make the template invalid) Now I get this error:

NotFound: Error creating or updating function key.

The API docs explain how it works, and I think it matches what I have here for the ARM template, but I can't seem to figure out why I get a not found error... Anyone ever tried this for an azure function slot? I can get it to work for the production slot though:

...,
{
    "type": "Microsoft.Web/sites/host/functionKeys",
    "dependsOn":[
      "[resourceId('Microsoft.Web/sites', variables('apiServiceName'))]"
    ],
    "apiVersion": "2018-11-01",
    "name": "[concat(variables('apiServiceName'), '/default/eventgrid')]",
    "properties": {
        "name": "event-grid"
    }
},...

Any help is appreciated.

Answer 1

This worked for me. I think you're missing the slot name in the name property:

{
    "type": "Microsoft.Web/sites/slots/host/functionKeys",
    "apiVersion": "2018-11-01",
    "name": "[concat(variables('functionAppName'), '/staging', '/default/key')]",
    "properties": {
        "name": "key",
        "value": "[parameters('key')]"
    },
    "dependsOn": [
        "[resourceId('Microsoft.Web/sites/slots', variables('functionAppName'), 'staging')]"
    ]
},