Remove sensitive files and their commits from Git history

Question

I would like to put a Git project on GitHub but it contains certain files with sensitive data (usernames and passwords, like /config/deploy.rb for capistrano).

I kno

Answer 1

So, It looks something like this:

git rm --cached /config/deploy.rb
echo /config/deploy.rb >> .gitignore

Remove cache for tracked file from git and add that file to .gitignore list