No matter how you like to participate in developer communities, Pulumi wants to meet you there. If you want to meet other Pulumi users to share use-cases and best practices, contribute code or documentation, see us at an event, or just tell a story about something cool you did with Pulumi, you are part of our community.

Pulumi Community

Hi everyone! How can I map an `Output&lt;T&gt;`, where T is a string containing a comma-separated list of IP addresses, into multiple resources where each resource takes one of those IP addresses as an input?
Case in point: `AppService` exposes `PossibleOutboundIpAddresses` as such an output property, and I need to transform that and create one `Sql.FirewallRule` for each IP address in that string. Of course I want to keep the chain of inputs-to-outputs intact to not break the dependency tracking etc.
Anyone know how to do this?

I think you can convert that output string using the youtString.Split(',').ToList()

So maybe like
var myIpList = resource.PossibleOutboundIpAddresses.Apply(x=&gt;x.Split(',').ToList())

Then you can loop over that ip list to add firewall rules.

Don’t think that works <@USER3UEJZ>. The Apply() function creates an Output, its values will be unknown at the time the Pulumi program is executed.

Besides that, Yes, Pulumi would have no notion of the dependency between the output property and the resources I  created in the loop…

But I think I have come up with something, maybe.

```appService.PossibleOutboundIpAddresses.Apply(x =&gt;
{
	var ipAddresses = x.Split(',').ToList();

	foreach (var ipAddress in ipAddresses)
	{
		var index = ipAddresses.IndexOf(ipAddress);
		var sqlFirewallRule = new FirewallRule(
			$"idl-licensing-{stackName}-sqlFirewallRule{index:D2}",
			new FirewallRuleArgs()
			{
				Name = Output.Format($"{appService.Name}-{index:D2}"),
				ResourceGroupName = resourceGroup.Name,
				ServerName = sqlServer.Name,
				StartIpAddress = ipAddress,
				EndIpAddress = ipAddress
			});
	}

	return Output.Create(false); // Not used for anything...
});```

It does work, but I think it won’t work for preview.

Here is a relevant example in TS <https://github.com/pulumi/examples/blob/master/azure-ts-appservice-devops/infra/index.ts#L106>

<@UB39JFCKC> :slightly_smiling_face: almost identical to what I did. Is it a correct assumption that this won’t preview correctly?

I haven’t tried this in anywhere recent CLI versions, but it might not indeed. Overall, this solution is not ideal, but seems required in this case, as the quantity of resources isn’t known in advance.

Ideally, it could be a single resource accepting a list of IPs (modelling issue again)

The bastards didn’t model their clouds with Pulumi in mind. :wink: