Access non-gcr public container registry from private GKE cluster

I want to deploy an the nginx-ingress-controller image (https://github.com/kubernetes/ingress-nginx) in my private GKE cluster but I can’t pull the image since it’s on quay.io’s registry. How can I pull a public image that’s not on GCR or the GCR Dockerhub mirror?

I thought about pulling it and uploading to my own GCR registry, but then I have to maintain updating it. Is there a way to keep a private mirror of just that image?

Source: StackOverflow