Auth Wrapper (#1174)

* Auth Wrapper

* Tweak cmd flag

* auth_excludes => auth_exclude

* Make Auth.Excludes variadic

* Use metadata.Get (passes through http and http2 it will go through various case formats)

* fix auth wrapper auth.Auth interface initialisation

Co-authored-by: Asim Aslam <asim@aslam.me>

options.go

@@ -18,6 +18,7 @@ import (
 
 // Options for micro service
 type Options struct {
+	Auth      auth.Auth
 	Broker    broker.Broker
 	Cmd       cmd.Cmd
 	Client    client.Client
@@ -40,6 +41,7 @@ type Options struct {
 
 func newOptions(opts ...Option) Options {
 	opt := Options{
+		Auth:      auth.DefaultAuth,
 		Broker:    broker.DefaultBroker,
 		Cmd:       cmd.DefaultCmd,
 		Client:    client.DefaultClient,
@@ -127,6 +129,7 @@ func Tracer(t trace.Tracer) Option {
 // Auth sets the auth for the service
 func Auth(a auth.Auth) Option {
 	return func(o *Options) {
+		o.Auth = a
 		o.Server.Init(server.Auth(a))
 	}
 }