Access different NAMESPACE of remote repo from client side

GIT_NAMESPACE is designed to be used mainly on the server side, that the server can serve multiple git repositories while share one single repository storage using different GIT_NAMESPACE settings.

Since we know that one remote repository hosts multiple namespaces, can we handle different namespaces in one local repository? Or can we access the proper namespace of the remote repository without complicated server settings?

At least there are three solutions for ssh protocol: pass namespace through environment, pass namespace in URL, or pass namespace from the proper settings of remote.<name>.receivepack and remote.<name>.uploadpack.

Solution 1: passing the namespace through environment.

 1. Set '/etc/sshd_config' in the server side as the following,
    so that the ssh server can accept GIT_NAMESPACE environment.

        AcceptEnv LANG LC_* GIT_NAMESPACE

 2. In the client side, When connect to ssh server, must send the
    GIT_NAMESPACE environment. This can be done with a remote-ext
    url:

        $ git remote add foo \
          'ext::ssh -o SendEnv=GIT_NAMESPACE git@server %S 'path/to/repo.git'

Then the remote "foo" is GIT_NAMESPACE aware, but when operate on this remote, must provide proper "--namespace" option.

    $ git --namespace=foo push foo master
    $ git --namespace=foo fetch foo
    $ git --namespace=foo ls-remote foo
    $ git --namespace=foo remote prune foo
    $ git --namespace=foo archive --remote foo HEAD

But provide a "--namespace" option is error-prone, but we may invent "remote.<name>.namespace" or something to set GIT_NAMESPACE automatically when push to or fetch from remote server.

Solution 2: passing the namespace in URL.

Again use remote-ext style URL to access remote repository:

    $ git remote add foo \
        'ext::ssh git@server git --namespace foo %s path/to/repo.git'

    $ git remote add bar \
        'ext::ssh git@server git --namespace bar %s path/to/repo.git'

But if the remote server use a limit shell (such as git-shell or gitolite), the above URLs won't work. This is because these git specific shell (git-shell or gitolite) do not like options.

Solution 3: use custom receivepack and uploadpack. e.g.

    [remote "foo"]
        url = ssh://git@server/path/to/repo.git
        receivepack = git --namespace foo receive-pack
        uploadpack = git --namespace foo upload-pack
        fetch = +refs/heads/*:refs/remotes/foo/*

    [remote "bar"]
        url = ssh://git@server/path/to/repo.git
        receivepack = git --namespace bar receive-pack
        uploadpack = git --namespace bar upload-pack
        fetch = +refs/heads/*:refs/remotes/foo/*

Just like solution 2, these settings won't work without a patched git-shell or gitolite.

I will send a patch in next email to address the latter two cases.