Ability to proxy multiple ECR registries at once

[james-callahan]

Currently ecr-proxy takes a single ECR repo to proxy via a command line argument.

This means to access different ECR registries a user needs to run multiple instances of ecr-proxy.

Instead, could you proxy to different accounts/registries based on e.g. a Host header?

[Ulexus]

Surely, but this is an extremely lightweight appliance. Why would you want to complicate the one instead of deploying multiple instances? When rubbing in a kubernetes environment (as it's planned, no?), I would generally prefer a micro services approach anyway.

It's also not just a concern of reading the host header. We would also need to have a whitelist to prevent us from being an open proxy.

[james-callahan]

Why would you want to complicate the one instead of deploying multiple instances?

Each instance run needs its own resources for base load as well as peak limits.
Going further: for multi-availability-zone scenarios, to lower interAZ networking costs you'd likely want to run it in each AZ.
I see this as a growing waste of resources that could be fixed if you handled multiple registries at once.

It's also not just a concern of reading the host header. We would also need to have a whitelist to prevent us from being an open proxy.

Yeah I would expect a configuration like: --accounts ecr-proxy-development.ecr-proxy.svc:123456789,ecr-proxy-production.ecr-proxy.svc:987654321 where you map specific hosts to specific ecr registries.