If I have two metrics:

kube_pod_container_status_restarts_total {..., pod="my_pod_name_42", ...}

and

container_memory_usage_bytes {..., pod_name="my_pod_name_42", cluster_name="megatron", ...}

And I want to set up alert for restart metrics, but containing cluster_name label. Can I somehow aggregate label value from different metrics.

For example alert:

increase(kube_pod_container_status_restarts_total{namespace="42"}[1h])>4    

need to somehow add megatron here ^, for alertmanager to be able to use this label when sending notification