Project clone init container cannot checkout revisions when auth is required.

[amisevsk]

Description

When working with git repositories that require authentication, the project-clone container can successfully clone and read the repo, but will fail to checkout any revision specified in the devfile.

This is because the checkout step relies on the go-git library, which does not automatically import the global gitconfig.

How To Reproduce

1. Set up either a PAT or SSH key for your account in the cluster
2. Start a workspace that uses a private project and specifies a checkoutFrom:

       projects:
         - name: private-project
           git: 
             remotes:
               origin: 'https://your-private-repo'
             checkoutFrom:
               revision: main

As a result, the project clone container will log something like

2022/09/01 17:00:03 Using temporary directory /projects/project-clone-2774327822
2022/09/01 17:00:03 Read DevWorkspace at /devworkspace-metadata/flattened.devworkspace.yaml
2022/09/01 17:00:03 Processing project private-project
2022/09/01 17:00:03 Cloning project private-project to /projects/project-clone-2774327822/private-project
Cloning into '/projects/project-clone-2774327822/private-project'...
fatal: unable to get credential storage lock in 1000 ms: Read-only file system
2022/09/01 17:00:05 Cloned project private-project to /projects/project-clone-2774327822/private-project
2022/09/01 17:00:05 Setting up remotes for project private-project
fatal: unable to get credential storage lock in 1000 ms: Read-only file system
2022/09/01 17:00:05 Fetched remote origin at https://your-private-repo
2022/09/01 17:00:05 Encountered error while setting up project private-project: failed to checkout revision: failed to read remote origin: authentication required

and the project will not be set up correctly; the cloned project will be present in a temporary directory named project-clone-<random-chars>.

Note the messages fatal: unable to get credential storage lock in 1000 ms: Read-only file system are expected at the moment as the credentials file is mounted to from a configmap and results in a read-only filesystem in that directory.

Expected behavior

Since the auth required to clone the project is set up, project-clone should be able to checkout any revision as required.

Workaround

1. Do not specify checkoutFrom for private repos
2. Change to the desired revision after the project is cloned