Auth Provider (#1309)

* auth provider mock interface

* Auth Provider Options

* Implement API Server Auth Package

* Add weh utils

* Add Login URL

* Auth Provider Options

* Add auth provider scope and setting token in cookie

* Remove auth_login_url flag

Co-authored-by: Asim Aslam <asim@aslam.me>
Co-authored-by: Ben Toogood <ben@micro.mu>

auth/provider/options.go

@@ -0,0 +1,47 @@
+package provider
+
+// Option returns a function which sets an option
+type Option func(*Options)
+
+// Options a provider can have
+type Options struct {
+	// ClientID is the application's ID.
+	ClientID string
+	// ClientSecret is the application's secret.
+	ClientSecret string
+	// Endpoint for the provider
+	Endpoint string
+	// Redirect url incase of UI
+	Redirect string
+	// Scope of the oauth request
+	Scope string
+}
+
+// Credentials is an option which sets the client id and secret
+func Credentials(id, secret string) Option {
+	return func(o *Options) {
+		o.ClientID = id
+		o.ClientSecret = secret
+	}
+}
+
+// Endpoint sets the endpoint option
+func Endpoint(e string) Option {
+	return func(o *Options) {
+		o.Endpoint = e
+	}
+}
+
+// Redirect sets the Redirect option
+func Redirect(r string) Option {
+	return func(o *Options) {
+		o.Redirect = r
+	}
+}
+
+// Scope sets the oauth scope
+func Scope(s string) Option {
+	return func(o *Options) {
+		o.Scope = s
+	}
+}