2016-08-12 02:47:26,054:WARNING:letsencrypt.cli:Attempting to renew cert from /etc/letsencrypt/renewal/www.chenghu.me.conf produced an unexpected error: 'server'. Skipping.
~ ssh-keygen -t rsa -C "mail@mail.com"
Generating public/private rsa key pair.
Enter file in which to save the key (/Users/username/.ssh/id_rsa): /Users/username/.ssh/id_rsa_github
Enter passphrase (empty for no passphrase):
Enter same passphrase again:
Your identification ...