Hello,
I see that I can pass a header with apikey to authenticate. Is there a way to change the header param name, so instead of apikey=actual_key I can pass my-api-key=actual_key?
Yes, you can add another name to the plugin default value.
curl -i -X POST --url http://localhost:8001/plugins/ \
--data "name=key-auth" \
--data "config.key_names[]=yourApiKeyName"
Thanks, we’ve been exploring it last year but now are in deployment mode 
Is there a way to do the same with the k8s ingress controller?
Yes. You can specify anything in the config block via the Ingress Controller as well.