Allow querying for multiple labels from ARM Template using listKeyValue

[jasonbrisbin]

I have been exploring the integration of App Configuration with ARM templates. Ideally I would like to be able to query for the value of key with an array of labels, returning only the first matching value.

Example scenario:
An overly simple example might be the following.

{
  "$schema": "https://schema.management.azure.com/schemas/2019-08-01/deploymentTemplate.json#",
  "contentVersion": "1.0.0.9",
  "parameters": {
    "environment": {
      "type": "String",
      "defaultValue": "dev",
      "metadata": {
        "description": "This is the SDLC environment that is being deployed to."
      }
    }
  },
  "variables": {
    "keyVaultName":"[concat(parameters('environment'),'-keyvault01')]",
    "skuFamily": {
      "key": "/keyvault/sku/family",
      "label": ["[variables('keyVaultName')]","[parameters('environment')]", "default"]
    },
    "skuName": {
      "key": "/keyvault/sku/name",
      "label": ["[variables('keyVaultName')]","[parameters('environment')]", "default"]
    },
    "enableSoftDelete": { 
      "key": "/keyvault/enableSoftDelete",
      "label": ["[variables('keyVaultName')]","[parameters('environment')]", "default"]
      }
  },
  "resources": [
    {
      "type": "Microsoft.KeyVault/vaults",
      "apiVersion": "2016-10-01",
      "name": "[variables('keyVaultName')]",
      "location": "northcentral",
      "properties": {
        "sku": {
          "family": "[listKeyValue(resourceId('Microsoft.AppConfiguration/configurationStores', 'appConfig01'), '2019-10-01',variables('skuFamily')).value]",          
          "name": "[listKeyValue(resourceId('Microsoft.AppConfiguration/configurationStores', 'appConfig01'), '2019-10-01',variables('skuName')).value]"
        },
        "accessPolicies": [],
        "tenantId": "53a61a04-8224-4d62-b270-a5823ebeb33c",
        "enabledForDeployment": false,
        "enabledForDiskEncryption": false,
        "enabledForTemplateDeployment": false,
        "enableSoftDelete": "[listKeyValue(resourceId('Microsoft.AppConfiguration/configurationStores', 'appConfig01'), '2019-10-01',variables('enableSoftDelete')).value]"
      }
    }
  ]
}

You can see that I am querying for some configuration Keys for Sku and enableSoftDelete. I am ordering my array of labels from most specific to least in this case. Enabling something like this would allow me to:

• Provide a default for everything (least specific).
  • All keyvaults will be deployed as standard
• Allow for an overload based on environment (more specific).
  • All keyvaults in production will be deployed as premium
• While also allowing me to handle an exception for a specific named instance (most specific).
  • This specific production keyvault should be standard.

[zhenlan]

@jasonbrisbin sorry for the late response. We are moving away from the listKeyValue API. Instead, we introduced KeyValues as a child resource in the new version 2020-07-01-preview, so you can query key-values by the standard ARM reference. Please check out the documentation for more details.

https://docs.microsoft.com/en-us/azure/azure-app-configuration/quickstart-resource-manager

[zhenlan]

@jasonbrisbin please let us know if you have further questions. Closing for now.

[jasonbrisbin]

I don't see where KeyValues would allow for querying a single key with multiple labels as I mentioned initially. Is that possible?

[zhenlan]

@jasonbrisbin you will have to query (reference) each key+label individually.

[jasonbrisbin]

If a key and label is not found will it throw an error?

[zhenlan]

I suppose referencing a key-value that does not exist will cause errors when running the template. @ZhijunZhao can you please confirm?

[ZhijunZhao]

@jasonbrisbin Yes, it would throw error like below.

C:\>az deployment group create -g test-resource-group --template-file app-config-kv-template.json
Deployment failed. Correlation ID: f4b71fb2-1ff2-4af3-9bd4-d5dd52bf4129. {
  "code": "EntityNotFound",
  "message": "The resource with id 'myKey$myLabel' was not found."
}

[jasonbrisbin]

The core problem then remains.

[zhenlan]

@jasonbrisbin ARM template does not support querying of multiple labels at once. But, @ZhijunZhao, is there a way to achieve what @jasonbrisbin wanted: query for the value of key with an array of labels, returning only the first matching value using what we have today?

[ZhijunZhao]

@zhenlan I think what @jasonbrisbin has is a sound case. But we have to add an API to support this. We could improve the listKeyValue API with key-label array input. More discussion is needed.

[jasonbrisbin]

Can we reopen this? I don't know why it was closed and would very much like this capability.

[zhenlan]

@jasonbrisbin sure, reopened. The listKeyValue API will not be continued in the new version. However, we need to figure out how to support the scenario via the 'KeyValue' resource.

[zhenlan]

cc: @jimmyca15 @MSGaryWang

[jasonbrisbin]

Any updates on this enhancement?