Is Istio/Envoy supported on a non-k8s deployment?

We're deploying an application that's in containers but not running on k8s, and has:

* an Angular front-end, using grpc-web

* a gRPC-web proxy (improbable-eng; golang)

* an nginx proxy (for Angular, and routing grpc traffic)

* an authentication manager (grpc+rust)

* an audit logging service (grpc+rust)

* a database service (grpc+kotlin)

* a 'logic' engine thing (grpc+kotlin)

* jaeger for distributed tracing

It's been a joy to develop, but I wouldn't mind reducing the 2 proxies to 1 with maybe Envoy. I tried rewriting grpc-web proxy in Rust, but gave up after struggling and not having enough time to complete it.