Auth (#1147)

Implement the Auth interface, with JWT and service implementations.

* Update Auth Interface

* Define Auth Service Implementation

* Support Service Auth

* Add Auth Service Proto

* Remove erronious files

* Implement Auth Service Package

* Update Auth Interface

* Update Auth Interface. Add Validate, remove Add/Remove roles

* Make Revoke interface more explicit

* Refactor serializing and deserializing service accounts

* Fix srv name & update interface to be more explicit

* Require jwt public key for auth

* Rename Variables (Resource.ID => Resource.Name & ServiceAccount => Account)

* Implement JWT Auth Package

* Remove parent, add ID

* Update auth imports to v2. Add String() to auth interface

server/options.go

@@ -5,6 +5,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/micro/go-micro/v2/auth"
 	"github.com/micro/go-micro/v2/broker"
 	"github.com/micro/go-micro/v2/codec"
 	"github.com/micro/go-micro/v2/debug/trace"
@@ -17,6 +18,7 @@ type Options struct {
 	Broker       broker.Broker
 	Registry     registry.Registry
 	Tracer       trace.Tracer
+	Auth         auth.Auth
 	Transport    transport.Transport
 	Metadata     map[string]string
 	Name         string
@@ -161,6 +163,13 @@ func Tracer(t trace.Tracer) Option {
 	}
 }
 
+// Auth mechanism for role based access control
+func Auth(a auth.Auth) Option {
+	return func(o *Options) {
+		o.Auth = a
+	}
+}
+
 // Transport mechanism for communication e.g http, rabbitmq, etc
 func Transport(t transport.Transport) Option {
 	return func(o *Options) {