Bugzilla Access through http authentication
 

I have installed bugzilla on Linux but i want to enable
HTTP authentication in it?
I have users already created in database of bugzilla but all i want
is to bring a popup when anyone try to access the bugzilla

You've probably already got something like the following to access Bugzilla. If you add the stuff in blue italics (change it for your own setup), you should get the authentication dialog you're looking for. There's info on setting up the password file at http://httpd.apache.org/docs/2.0/howto/auth.html:

But i have already passwords and users existing in the bugzilla Database

Do you mean that you want the user authentication to happen in the dialog instead of the form but still be the info in the Bugzilla database? If so, I misunderstood - both of the Bugzilla instances I run use the authentication in the standard login form.

I want to use the authentication not in the webform but through http [www] authentication. But i want to use the credentials that are already present in the bugzilla database.

I haven't done any work with the mod_dbd stuff, but there's information at http://httpd.apache.org/docs/trunk/mod/mod_dbd.html which may be helpful.

Also, there may be more specific information at news://news.mozilla.org/mozilla.support.bugzilla.