This is a bug or my usage is wrong?

[dxvgef]

I use echo v3, I repeat the request controller (refresh page), it will create a number of records in redis scs / session, this is a bug or I use the wrong method?
the code is probably this:

main.go

engine := redisstore.New(
	&redis.Pool{
		MaxIdle: 10,
		Dial: func() (redis.Conn, error) {
			return redis.Dial("tcp", "127.0.0.1:6379")
		},
	},
)

sessionManager := session.Manage(
	engine,
	session.HttpOnly(true),
	session.IdleTimeout(20*time.Minute),
	session.Lifetime(3*time.Hour),
)
App.Use(echo.WrapMiddleware(sessionManager))

Controller

func Index(ctx echo.Context) error {
	data := make(map[string]interface{})
	session.PutString(ctx.Request(), "sess", "ok")
	data["sess"], _ = session.GetString(ctx.Request(), "sess")
	return ctx.Render(200, "index.jet", data)
}

Refresh three pages, redis appeared in three records, I think this is not normal?

[alexedwards]

Sorry for the (very) slow reply.

This is happening because the session cookie is never being written by the SCS middleware. I think the session cookie isn't being written because Echo's WrapMiddleware doesn't actually pass the underlying http.ResponseWriter onwards -- it replaces it entirely it's own c.Response() object instead and the session manager's Write method is therefore never called.

func WrapMiddleware(m func(http.Handler) http.Handler) MiddlewareFunc {
	return func(next HandlerFunc) HandlerFunc {
		return func(c Context) (err error) {
			m(http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
				c.SetRequest(r)
				err = next(c)
			})).ServeHTTP(c.Response(), c.Request())
			return
		}
	}
}

Unless Echo can be changed so that WrapMiddleware extends the underlying http.ResponseWriter instead of replacing it, the only 'fix' I can see is to call session.Save manually in your handlers which modify the session data, like so:

func Index(ctx echo.Context) error {
	data := make(map[string]interface{})
	session.PutString(ctx.Request(), "sess", "ok")
        _ = session.Save(c.Response(), c.Request())
	data["sess"], _ = session.GetString(ctx.Request(), "sess")
	return ctx.Render(200, "index.jet", data)
}

This essentially writes the session data and cookie, instead of relying on the middleware to do it.