Outbound IP Registration to Azure SQL Using Azure Functions

UpdateFirewallRulesHttpTrigger-4.cs

[FunctionName("UpdateFirewallRulesHttpTrigger")]
public static async Task<HttpResponseMessage> Run(
    [HttpTrigger(AuthorizationLevel.Function, "post", Route = "firewall/rules")]HttpRequestMessage req,
    TraceWriter log)
{
    ...

    log.Info($"Firewall rules on database servers in {resourceGroupName} are updating...");

    ...

    var tasks = new List<Task>();

    var servers = await azure.SqlServers
                             .ListByResourceGroupAsync(resourceGroupName)
                             .ConfigureAwait(false);
    foreach (var server in servers)
    {
        var registeredIps = server.FirewallRules
                                  .List()
                                  .ToDictionary(p => p.Name, p => p.StartIPAddress);
        var ipsToExclude = registeredIps.Where(p => !outboundIps.Contains(p.Value))
                                        .Select(p => p.Key)
                                        .ToList();
        var IpsToInclude = outboundIps.Where(p => !registeredIps.ContainsValue(p))
                                      .ToList();

        var tasksToExclude = ipsToExclude.Select(ip => server.FirewallRules
                                                             .DeleteAsync(ip));
        var tasksToInclude = IpsToInclude.Select(ip => server.FirewallRules
                                                             .Define($"webapp-{ip.Replace(".", "-")}")
                                                             .WithIPAddressRange(ip, ip)
                                                             .CreateAsync());
        tasks.AddRange(tasksToExclude);
        tasks.AddRange(tasksToInclude);
    }

    await Task.WhenAll(tasks).ConfigureAwait(false);

    log.Info($"Firewall rules on database servers in {resourceGroupName} have been updated.");

    return req.CreateResponse(HttpStatusCode.OK);
}