Daggerize Envoy

[peterj]

Here's the initial idea I had (but wanted to start small) that would allow you to craft Envoy configuration using code; something like this:

listener := EnvoyListener(5000, "listener1") 
cluster := EnvoyCluster("my-cluster", { ...}).WithEndpoints("httpbin.org", "443", { ... })
route := EnvoyRoute("hello.com", { path: "/hello", match: {...}}).WithCluster(cluster)

dag.EnvoyProxy(version, platform).
    WithListener(5000, "listener1", {...}).
    WithRoutes(route)
...

There are only a couple of basic building blocks (listeners, routes, clusters, endpoints) that would need to be expressed (+ bunch of other options that could be passed in later).