#138: add Secure attribute to viewer cookie (vwr)

internal/api/server.go

@@ -141,9 +141,12 @@ func viewerCookieMiddleware(next http.Handler) http.Handler {
 	return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
 		if c, err := r.Cookie("vwr"); err != nil || c.Value == "" {
 			id := store.GenSlug(16)
+			// #138: Secure keeps the viewer id off plain-HTTP requests
+			// (all deployments are HTTPS-only behind traefik).
 			http.SetCookie(w, &http.Cookie{
 				Name: "vwr", Value: id, Path: "/",
-				MaxAge: 31536000, HttpOnly: true, SameSite: http.SameSiteLaxMode,
+				MaxAge: 31536000, HttpOnly: true, Secure: true,
+				SameSite: http.SameSiteLaxMode,
 			})
 			r.AddCookie(&http.Cookie{Name: "vwr", Value: id})
 			// remember that this cookie was minted here, not sent by the client