Pass ignored IPs to proxy init container

[Neurostep]

Description of changes:

We are in the process of migrating off the AWS AppMesh to AWS VPC Lattice. We have our workloads in both EKS and ECS. Some services in EKS have connections to services in ECS. In order to migrate a service in AWS ECS to VPC Lattice we need to adjust AppMesh service deployment in EKS to ignore the IP ranges of the VPC Lattice.

To deploy AppMesh resources in EKS we use CRDs defined in appmesh-controller. We deploy our appmesh-controller using Helm chart.

In order to override the default APPMESH_EGRESS_IGNORED_IP of the proxyinit init container we tried to use appmesh.k8s.aws/egressIgnoredIPs annotation. But it turned out it is not respected as the value explicitly refers to the controller's configuration and there is no way to specify --ignored-ips argument for the controller in the Helm Chart.

In this PR, I patched the proxyMutator so it respects the annotation to override egress ignored IPs.

Testing

I created the custom controller image, pushed it in our ECR repository and tested the changes. With this patch, the proxyinit init container is properly get the APPMESH_EGRESS_IGNORED_IP environment variable provided by controller.

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[joesbigidea]

This looks great. Thanks for the change.