An issue about permission - help

[kflee2000]

I follow the tutorial step by step and so far so good until it come to create webapp:

root@Dell-Inspiron-3543:~/snap# docker build -t kflee2000/catnip . error checking context: 'no permission to read from '/root/snap/Dockerfile''.

The file Dockerfile: -rw-r--r-- 1 root root 233 Jul 13 21:45 Dockerfile so just wonder where is the permission refer to. Help appreciated.