Add single instance mode

bloat.conf

@@ -25,6 +25,13 @@ client_scope=read write follow
 # Example: "http://localhost:8080", "https://mydomain.com"
 client_website=http://localhost:8080
 
+# In single instance mode, bloat will not ask for instance domain name and
+# user will be directly redirected to login form. User login from other
+# instances is not allowed in this mode.
+# Empty value disables single instance mode.
+# Example: "mydomain.com"
+single_instance=
+
 # Path of database directory. It's used to store session information.
 database_path=database
 

config/config.go

@@ -15,6 +15,7 @@ type config struct {
 	ClientName      string
 	ClientScope     string
 	ClientWebsite   string
+	SingleInstance  string
 	StaticDirectory string
 	TemplatesPath   string
 	DatabasePath    string
@@ -68,6 +69,8 @@ func Parse(r io.Reader) (c *config, err error) {
 			c.ClientScope = val
 		case "client_website":
 			c.ClientWebsite = val
+		case "single_instance":
+			c.SingleInstance = val
 		case "static_directory":
 			c.StaticDirectory = val
 		case "templates_path":

main.go

@@ -101,7 +101,7 @@ func main() {
 
 	s := service.NewService(config.ClientName, config.ClientScope,
 		config.ClientWebsite, customCSS, config.PostFormats, renderer,
-		sessionRepo, appRepo)
+		sessionRepo, appRepo, config.SingleInstance)
 	s = service.NewAuthService(sessionRepo, appRepo, s)
 	s = service.NewLoggingService(logger, s)
 	handler := service.NewHandler(s, config.StaticDirectory)

service/service.go

@@ -35,6 +35,7 @@ type Service interface {
 	ServeSearchPage(ctx context.Context, c *model.Client, q string, qType string, offset int) (err error)
 	ServeUserSearchPage(ctx context.Context, c *model.Client, id string, q string, offset int) (err error)
 	ServeSettingsPage(ctx context.Context, c *model.Client) (err error)
+	SingleInstance(ctx context.Context) (instance string, ok bool)
 	NewSession(ctx context.Context, instance string) (redirectUrl string, sessionID string, err error)
 	Signin(ctx context.Context, c *model.Client, sessionID string,
 		code string) (token string, userID string, err error)
@@ -70,6 +71,7 @@ type service struct {
 	renderer       renderer.Renderer
 	sessionRepo    model.SessionRepo
 	appRepo        model.AppRepo
+	singleInstance string
 }
 
 func NewService(clientName string,
@@ -80,6 +82,7 @@ func NewService(clientName string,
 	renderer renderer.Renderer,
 	sessionRepo model.SessionRepo,
 	appRepo model.AppRepo,
+	singleInstance string,
 ) Service {
 	return &service{
 		clientName:     clientName,
@@ -90,6 +93,7 @@ func NewService(clientName string,
 		renderer:       renderer,
 		sessionRepo:    sessionRepo,
 		appRepo:        appRepo,
+		singleInstance: singleInstance,
 	}
 }
 
@@ -622,6 +626,14 @@ func (svc *service) ServeSettingsPage(ctx context.Context, c *model.Client) (err
 	return svc.renderer.Render(rCtx, c.Writer, renderer.SettingsPage, data)
 }
 
+func (svc *service) SingleInstance(ctx context.Context) (instance string, ok bool) {
+	if len(svc.singleInstance) > 0 {
+		instance = svc.singleInstance
+		ok = true
+	}
+	return
+}
+
 func (svc *service) NewSession(ctx context.Context, instance string) (
 	redirectUrl string, sessionID string, err error) {
 

service/transport.go

@@ -14,12 +14,24 @@ import (
 	"github.com/gorilla/mux"
 )
 
+const (
+	sessionExp = 365 * 24 * time.Hour
+)
+
 func newClient(w io.Writer) *model.Client {
 	return &model.Client{
 		Writer: w,
 	}
 }
 
+func setSessionCookie(w http.ResponseWriter, sessionID string, exp time.Duration) {
+	http.SetCookie(w, &http.Cookie{
+		Name:    "session_id",
+		Value:   sessionID,
+		Expires: time.Now().Add(exp),
+	})
+}
+
 func newCtxWithSesion(req *http.Request) context.Context {
 	ctx := context.Background()
 	sessionID, err := req.Cookie("session_id")
@@ -93,6 +105,19 @@ func NewHandler(s Service, staticDir string) http.Handler {
 	signinPage := func(w http.ResponseWriter, req *http.Request) {
 		c := newClient(w)
 		ctx := context.Background()
+		instance, ok := s.SingleInstance(ctx)
+		if ok {
+			url, sessionID, err := s.NewSession(ctx, instance)
+			if err != nil {
+				w.WriteHeader(http.StatusInternalServerError)
+				s.ServeErrorPage(ctx, c, err)
+				return
+			}
+
+			setSessionCookie(w, sessionID, sessionExp)
+			w.Header().Add("Location", url)
+			w.WriteHeader(http.StatusFound)
+		} else {
 			err := s.ServeSigninPage(ctx, c)
 			if err != nil {
 				w.WriteHeader(http.StatusInternalServerError)
@@ -100,6 +125,7 @@ func NewHandler(s Service, staticDir string) http.Handler {
 				return
 			}
 		}
+	}
 
 	timelinePage := func(w http.ResponseWriter, req *http.Request) {
 		c := newClient(w)
@@ -291,12 +317,7 @@ func NewHandler(s Service, staticDir string) http.Handler {
 			return
 		}
 
-		http.SetCookie(w, &http.Cookie{
-			Name:    "session_id",
-			Value:   sessionID,
-			Expires: time.Now().Add(365 * 24 * time.Hour),
-		})
-
+		setSessionCookie(w, sessionID, sessionExp)
 		w.Header().Add("Location", url)
 		w.WriteHeader(http.StatusFound)
 	}
@@ -689,12 +710,8 @@ func NewHandler(s Service, staticDir string) http.Handler {
 		ctx := newCtxWithSesionCSRF(req, req.FormValue("csrf_token"))
 
 		s.Signout(ctx, c)
-		http.SetCookie(w, &http.Cookie{
-			Name:    "session_id",
-			Value:   "",
-			Expires: time.Now(),
-		})
 
+		setSessionCookie(w, "", 0)
 		w.Header().Add("Location", "/")
 		w.WriteHeader(http.StatusFound)
 	}