So, we can use somebody else's work from a remote repository, but
how can you prepare a repository to let other people pull from
it?
You do your real work in your working tree that has your primary
repository hanging under it as its .git subdirectory. You could
make that repository accessible remotely and ask people to pull
from it, but in practice that is not the way things are usually
done. A recommended way is to have a public repository, make it
reachable by other people, and when the changes you made in your
primary working tree are in good shape, update the public
repository from it. This is often called pushing.
Note
This public repository could further be mirrored, and that is
how Git repositories at kernel.org are managed.
Publishing the changes from your local (private) repository to
your remote (public) repository requires a write privilege on the
remote machine. You need to have an SSH account there to run a
single command, git-receive-pack.
First, you need to create an empty repository on the remote
machine that will house your public repository. This empty
repository will be populated and be kept up to date by pushing
into it later. Obviously, this repository creation needs to be
done only once.
Note
git push uses a pair of commands, git send-pack on your local
machine, and git-receive-pack on the remote machine. The
communication between the two over the network internally
uses an SSH connection.
Your private repository's Git directory is usually .git, but your
public repository is often named after the project name, i.e.
<project>.git. Let's create such a public repository for project
my-git. After logging into the remote machine, create an empty
directory:
$ mkdir my-git.git
Then, make that directory into a Git repository by running git
init, but this time, since its name is not the usual .git, we do
things slightly differently:
$ GIT_DIR=my-git.git git init
Make sure this directory is available for others you want your
changes to be pulled via the transport of your choice. Also you
need to make sure that you have the git-receive-pack program on
the $PATH.
Note
Many installations of sshd do not invoke your shell as the
login shell when you directly run programs; what this means
is that if your login shell is bash, only .bashrc is read and
not .bash_profile. As a workaround, make sure .bashrc sets up
$PATH so that you can run git-receive-pack program.
Note
If you plan to publish this repository to be accessed over
http, you should do mv my-git.git/hooks/post-update.sample
my-git.git/hooks/post-update at this point. This makes sure
that every time you push into this repository, git
update-server-info is run.
Your "public repository" is now ready to accept your changes.
Come back to the machine you have your private repository. From
there, run this command:
$ git push <public-host>:/path/to/my-git.git master
This synchronizes your public repository to match the named
branch head (i.e. master in this case) and objects reachable from
them in your current repository.
As a real example, this is how I update my public Git repository.
Kernel.org mirror network takes care of the propagation to other
publicly visible machines:
$ git push master.kernel.org:/pub/scm/git/git.git/
