manageAzureFunctionKeys.ps1

param(
    [parameter(Mandatory=$true)] [string]$functionName,
    [parameter(Mandatory=$true)] [string]$appName,
    [parameter(Mandatory=$true)] [string]$resourceGroup,
    [parameter(Mandatory=$true)] [string]$key
)

function Get-KuduCredentials($appName, $resourceGroup) {

    [xml]$x = Get-AzureRmWebAppPublishingProfile -ResourceGroupName $resourceGroup -Name $appName
    $user = $x.publishData.publishProfile[1].userName.Split("\") | Select-Object -Last 1
    $pass = $x.publishData.publishProfile[1].userPWD
    $pair = "$($user):$($pass)"

    $encodedCreds = [System.Convert]::ToBase64String([System.Text.Encoding]::ASCII.GetBytes($pair))
    return $encodedCreds
}

function Get-FunctionKey([string]$appName, [string]$functionName, [string]$encodedCreds) {
    $jwt = Invoke-RestMethod -Uri "https://$appName.scm.azurewebsites.net/api/functions/admin/token" -Headers @{Authorization = ("Basic {0}" -f $encodedCreds)} -Method GET

    $keys = Invoke-RestMethod -Method GET -Headers @{Authorization = ("Bearer {0}" -f $jwt)} `
        -Uri "https://$appName.azurewebsites.net/admin/functions/$functionName/keys"
    # -Uri "https://$appName.azurewebsites.net/admin/functions/$functionName/keys/default"
    $code = $keys.keys[0].value
    return $code
}

function Set-FunctionKey([string]$appName, [string]$functionName,[string]$keyValue, [string]$encodedCreds) {
    $jwt = Invoke-RestMethod -Uri "https://$appName.scm.azurewebsites.net/api/functions/admin/token" -Headers @{Authorization = ("Basic {0}" -f $encodedCreds)} -Method GET
    $body = "{
        ""name"": ""adf"",
        ""value"" : ""$($keyvalue)""
      }"
    $keys = Invoke-RestMethod -Method PUT -Headers @{Authorization = ("Bearer {0}" -f $jwt)} `
        -Uri "https://$appName.azurewebsites.net/admin/functions/$functionName/keys/adf" `
        -Body $body `
        -ContentType 'application/json'
    return $keys
}

if ([string]::IsNullOrEmpty($(Get-AzureRmContext).Account)) {
    Login-AzureRmAccount
}

$kuduCreds = Get-KuduCredentials $appName $resourceGroup
Set-FunctionKey $appName $functionName $key $kuduCreds