Setting up a Git server

[quiliro@riseup.net]

Hello Guix.

I have set up a git server on one machine by adding openssh as a service
in my guix system reconfigure file:

(operating-system
  [...]
  (services (cons*
             (service openssh-service-type
                      (openssh-configuration
                       (port-number 2222)))
             [...])))

And on a wheel user, I typed the command:
sudo guix system reconfigure config.scm

On a regular user, I added git:
guix install git

I created a new directory and made it a repository with:
mkdir git_test
chmod 770 git_test
cd git_test
git init

I added a new file and commited that file:
echo "This is the first text of the first file." > new_file
git add .
git commit -m "First file added for testing."

So now, from a remote machine which has Git installed, I can:
git clone git clone \
ssh://remote_user@remote_server_IP_address:2222/home/remote_user/git_test

Everything is fairly well. But not as well as I expected. I have the
following problems:
- no users can push
- everyone mush pull with the remote_user's password

How can each user push with their own password?