Add error to GetSession return values

- Add button to copy instance SSH access

handlers/home.go

@@ -7,17 +7,21 @@ import (
 	"path/filepath"
 
 	"github.com/gorilla/mux"
+	"github.com/play-with-docker/play-with-docker/storage"
 )
 
 func Home(w http.ResponseWriter, r *http.Request) {
 	vars := mux.Vars(r)
 	sessionId := vars["sessionId"]
 
-	s := core.SessionGet(sessionId)
-	if s == nil {
+	s, err := core.SessionGet(sessionId)
+	if err == storage.NotFoundError {
 		// Session doesn't exist (can happen if closing the sessions an reloading the page, or similar).
 		w.WriteHeader(http.StatusNotFound)
 		return
+	} else if err != nil {
+		w.WriteHeader(http.StatusInternalServerError)
+		return
 	}
 	if s.Stack != "" {
 		go core.SessionDeployStack(s)