AWS MediaLive Cloudformation Fn::GetAtt get array value

Question

I am building a Cloudformation template for Media Live I have everything working with the AWS PHP SDK. I create a channel and return the Channels data to be used in the next call.

Return example.

(
    [Arn] => arn:aws:mediapackage:us-east-1:000000000000:channels/000000000000
    [Description] => Tests
    [HlsIngest] => Array
        (
            [IngestEndpoints] => Array
                (
                    [0] => Array
                        (
                            [Id] => 000000000000
                            [Password] => 000000000000
                            [Url] => https://000000000000.mediapackage.us-east-1.amazonaws.com/in/v2/1e803c424d2947f58c07d9a6a5ff3d31/000000000000/channel
                            [Username] => 000000000000
                        )

                    [1] => Array
                        (
                            [Id] => 000000000000
                            [Password] => 000000000000
                            [Url] => https://2bcff136c2fbf1e5.mediapackage.us-east-1.amazonaws.com/in/v2/000000000000/10392b8387fd442eae56f29ac2656837/channel
                            [Username] => 000000000000
                        )

                )

        )

    [Id] => sdv
    [Tags] => Array
        (
        )
)

I can then use these values in PHP like this.

$destinationOneUrl = $createChannel['HlsIngest']['IngestEndpoints'][0]['Url'];

Which works but with Cloudformation you have to use the Fn::GetAtt like this.

"Destinations": [{
                    "Id": "destination1",
                    "Settings": [{
                            "Url": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                            "Username": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                            "PasswordParam": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                        },
                        {
                            "Url": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                            "Username": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                            "PasswordParam": {
                                "Fn::GetAtt": ["MediaPackageChannel", "HlsIngest"]
                            },
                        }
                    ]
                }],

You cannot go into the array with this is there another function that can be used in combination with the Fn::GetAtt to get the inner values.

Something along these lines

"Fn::GetAtt": ["MediaPackageChannel", "HlsIngest['IngestEndpoints'][0]['Url']"]

Here is my full template its hard to explain but basically I need to attach my medialive channel to the mediapackage channel as I mention I have done with the php code above Cloudformation doesn't make this easy.

You will see the Destinations section line 39 I need to populate the Url, Username, PasswordParam with the returned values from the mediapackage channel creation.

https://gist.github.com/samueleastdev/03b050f937855a81f36bb1e3260aa5d3