Apache authentification

# vi /etc/apache2/sites-enabled/000-default.conf

...

AllowOverride AuthConfig
Options MultiViews Indexes SymLinksIfOwnerMatch IncludesNoExec
Order allow,deny
Allow from all

...

cat < /var/www/html/.htaccess
AuthBasicAuthoritative On
AuthName "Authorized Users Only."
AuthType Basic
AuthUserFile /etc/apache2/htpasswd
Require user USER_NAME
EOF

htpasswd -b /etc/apache2/htpasswd USER_NAME 'USER_PASS'