Add offline token option

Login needs to add an offline token flag to ensure a refresh token is returned by the token endpoint.

Signed-off-by: Derek McGowan <derek@mcgstyle.net> (github: dmcgowan)

registry/client/auth/session.go

@@ -116,6 +116,7 @@ type tokenHandler struct {
 	transport http.RoundTripper
 	clock     clock
 
+	offlineAccess bool
 	forceOAuth    bool
 	clientID      string
 	scopes        []Scope
@@ -149,6 +150,7 @@ type TokenHandlerOptions struct {
 	Transport   http.RoundTripper
 	Credentials CredentialStore
 
+	OfflineAccess bool
 	ForceOAuth    bool
 	ClientID      string
 	Scopes        []Scope
@@ -182,6 +184,7 @@ func NewTokenHandlerWithOptions(options TokenHandlerOptions) AuthenticationHandl
 	handler := &tokenHandler{
 		transport:     options.Transport,
 		creds:         options.Credentials,
+		offlineAccess: options.OfflineAccess,
 		forceOAuth:    options.ForceOAuth,
 		clientID:      options.ClientID,
 		scopes:        options.Scopes,
@@ -346,6 +349,10 @@ func (th *tokenHandler) fetchTokenWithBasicAuth(realm *url.URL, service string,
 		reqParams.Add("scope", scope)
 	}
 
+	if th.offlineAccess {
+		reqParams.Add("offline_token", "true")
+	}
+
 	if th.creds != nil {
 		username, password := th.creds.Basic(realm)
 		if username != "" && password != "" {