Is there a way to convert an

Output<T>

to a string?

No, not really.

Output

may only resolve after the deployment is done. You usually want to use

apply

to manipulate the value.

I am trying to get an eks cluster name and then set a tag for a nodegroup's ASG tags.

const caClusterName = "<http://k8s.io/cluster-autoscaler/|k8s.io/cluster-autoscaler/>" + clusterObj.eksCluster.name.apply(n => n);
...
autoScalingGroupTags: {
        "<http://k8s.io/cluster-autoscaler/enabled|k8s.io/cluster-autoscaler/enabled>": "true",
        [ caClusterName ] : "true"
},``

You can try something like that:

autoScalingGroupTags: clusterObj.eksCluster.name.apply(clusterName => ({
        "<http://k8s.io/cluster-autoscaler/enabled|k8s.io/cluster-autoscaler/enabled>": "true",
        [ "<http://k8s.io/cluster-autoscaler/|k8s.io/cluster-autoscaler/>" + clusterName ] : "true"
}),