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

auth/options.go

@@ -0,0 +1,57 @@
+package auth
+
+import (
+	b64 "encoding/base64"
+)
+
+type Options struct {
+	PublicKey  []byte
+	PrivateKey []byte
+}
+
+type Option func(o *Options)
+
+// PublicKey is the JWT public key
+func PublicKey(key string) Option {
+	return func(o *Options) {
+		o.PublicKey, _ = b64.StdEncoding.DecodeString(key)
+	}
+}
+
+// PrivateKey is the JWT private key
+func PrivateKey(key string) Option {
+	return func(o *Options) {
+		o.PrivateKey, _ = b64.StdEncoding.DecodeString(key)
+	}
+}
+
+type GenerateOptions struct {
+	Metadata map[string]string
+	Roles    []*Role
+}
+
+type GenerateOption func(o *GenerateOptions)
+
+// Metadata for the generated account
+func Metadata(md map[string]string) func(o *GenerateOptions) {
+	return func(o *GenerateOptions) {
+		o.Metadata = md
+	}
+}
+
+// Roles for the generated account
+func Roles(rs []*Role) func(o *GenerateOptions) {
+	return func(o *GenerateOptions) {
+		o.Roles = rs
+	}
+}
+
+// NewGenerateOptions from a slice of options
+func NewGenerateOptions(opts ...GenerateOption) GenerateOptions {
+	var options GenerateOptions
+	for _, o := range opts {
+		o(&options)
+	}
+
+	return options
+}