不确定 ac 是否按照 appropriate user name for your AMI and that you have specified the proper private key (.pem) file for your instance. 设定了
If you connect to your instance using SSH and get any of the following errors, Host key not found in [directory] , Permission denied (publickey) , Authentication failed, permission denied , or Connection closed by [instance] port 22 , verify that you are connecting with the appropriate user name for your AMI and that you have specified the proper private key (.pem) file for your instance.