robdmoore
commented
6 years ago I've managed to get this working with the following code:
function Get-AccessToken($tenantId) {
$context = Get-AzureRmContext
$cache = $context.TokenCache
$cacheItem = $null
try {
$cacheItem = $cache.ReadItems() | Where-Object { $_.TenantId -eq $tenantId } | Select-Object -First 1
} catch {
$cache = [Microsoft.IdentityModel.Clients.ActiveDirectory.TokenCache]::DefaultShared
}
if (-not $cacheItem) {
# Service principals don't have a tenant id specified in the cache item
$cacheItem = $cache.ReadItems() | Select-Object -First 1
if ($cacheItem.TenantId) {
throw "Couldn't find an access token for the current user"
}
}
return $cacheItem.AccessToken
}
Write-Host "Getting master key for $functionName function app"
$headers = @{
Authorization = "Bearer $(Get-AccessToken -tenantId $TenantId)"
}
$masterKeyContent = Invoke-WebRequest -Uri "https://$functionName.scm.azurewebsites.net/api/functions/admin/masterkey" -Headers $headers | select -Expand Content | ConvertFrom-Json
$masterKey = $masterKeyContent.masterKey.ToString()
Write-Host "Getting system key for the Event Grid extension"
$attempt = 1
$content = $null
while ((-not $content) -and $attempt -le 12) {
if ($attempt -gt 1) {
Start-Sleep -Seconds 10
}
try {
$content = Invoke-WebRequest "https://$functionName.azurewebsites.net/admin/host/systemkeys/eventgridextensionconfig_extension?code=$masterKey" | select -Expand Content | ConvertFrom-Json
} catch {
Write-Warning "Error getting key, trying again"
Write-Warning $_
}
$attempt = $attempt + 1
}
$eventGridWebHookCode = $content.value.ToString()Then pass in the $eventGridWebHookCode to your ARM script as a parameter from PowerShell and you can use it similar to the example below (just change SurveyEmailer with your function name and Swap out SurveyReady with All, or a list of the types you want to subscribe to - you can also add the prefix etc. filters too) to set up a subscription:
{
"name": "[concat(parameters('appName'), '/Microsoft.EventGrid/SurveyEmailer')]",
"type": "Microsoft.EventGrid/topics/providers/eventSubscriptions",
"location": "[resourceGroup().location]",
"apiVersion": "2018-01-01",
"properties": {
"destination": {
"endpointType": "WebHook",
"properties": {
"endpointUrl": "[concat('https://', reference(resourceId('Microsoft.Web/sites', variables('functionsAppName')), '2015-08-01').defaultHostName, '/runtime/webhooks/eventgrid?functionName=SurveyEmailer&code=', uriComponent(parameters('eventGridWebhookCode')))]"
}
},
"filter": {
"includedEventTypes": [
"SurveyReady"
]
}
},
"condition": "[variables('addEventGridSubscriptions')]",
"dependsOn": [
"[resourceId('Microsoft.EventGrid/topics', parameters('appName'))]",
"[resourceId('Microsoft.Web/sites/', variables('functionsAppName'))]"
]
},Note, the URL to use for the webhook endpoint is different in the latest v2 functions runtime vs v1 so be sure to get the right one for your code.
There is an issue being tracked here to make this easier: https://github.com/Azure/Azure-Functions/issues/516#issuecomment-417427044.
Note: there is a chicken and egg in that the function app needs to exist with the event grid function extension installed and deployed for the key to be able to be generated using the above code so you either need to execute it as a second ARM template or use a condition (like I have above) and execute the ARM template twice the first time you deploy the function app).
nhart12
vladislav-mitev
blueelvis
pragnagopa
mslot
mathewc
alex-nanai
Presently using ARM I can automate the creation of an Azure Function Subscriber that has a HTTP trigger.
"properties": { "destination": { "endpointType": "WebHook", "properties": { "endpointUrl": "[listsecrets(resourceId('Microsoft.Web/sites/functions', parameters('azurefunctions_name'), parameters('azurefunctions_loadTcsItemSubscription')),'2015-08-01').trigger_url]" } }, "filter": { "includedEventTypes": [ "All" ] } },
I am however unable to do the same for an Azure Function Event Grid trigger, there seems to be no way of accessing the system key.
Many Thanks