Rewriting history – changing a single file

In this example, we'll see how we can use Git filter-branch to remove sensitive data from a file throughout the repository history.

Getting ready

For simplicity, we'll use a very simple example repository. It contains a few files. One of them is .credentials, which contains a username and password. Start by cloning the repository and changing the directory, as shown in the following command:

$ git clone https://github.com/PacktPublishing/Git-Version-Control-Cookbook-Second-Edition_Remove-Credentials.git 
$ cd Git-Version-Control-Cookbook-Second-Edition_Remove-Credentials 

Before proceeding, you can take a look at the content of the repository using ls and examine the history with git log.

How to do it...

1. As we need to modify a file when rewriting the history of this repository, we'll use the tree-filter option to filter the branch. The .credentials file looks as follows:

username = foobar
password = verysecret 

2. All we need to do is remove everything after...