How to use htpasswd For CKAN Instance
You are using nginx, arent you?
So you can make the athentification with nginx with just adding two lines to one file and creating a password file. 
In /etc/nginx/sites-available/ckan add following lines:
auth_basic "Restricted";
auth_basic_user_file /filedestination;
then create create a file at your filedestination with following content:
USERNAME:PASSWORD 
The password must be in md5.
Have fun with ckan!
I have included Location header in My Virtual Host file.

AuthType Basic
AuthName "Restricted"
AuthUserFile /etc/httpd/.htpasswd
require valid-user

Also created user to access the domain. but the user i have created using htpasswd is not allow other user to make any activity in CKAN Instance.
anyone Have an idea..Please let me know