Question: Can I have different AKS instances target a single Application Gateway?

[ptemmer]

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I read this in the documentation:

For deployments that require more than one AGIC per cluster or multiple AGICs targeting one Application Gateway, please continue to use AGIC deployed through Helm.

However, it is not clear to me whether this means the multiple AGIC instances can be spread over AKS clusters, or whether they have to run on the same cluster.

I have a couple of clusters for which I would like to use the same Application Gateway, basically to reduce costs.

[ptemmer]

It seems this is possible: https://docs.microsoft.com/en-us/azure/application-gateway/ingress-controller-install-existing#multi-cluster--shared-application-gateway

However, not very manageable if you ask me. You need to explicitly set which hostnames NOT to consider. Wouldn't it make more sense to have to specify which hostname I DO want AGIC to handle? I'm unable to know at all times which ingress hostnames are specified in the other cluster..