Configure an open-source git repository to not need username and password when clone and pull

Question

This is my first time I create a git server. I create a git https server with Nginx as a webserver, fcgiwrap as interface to the git-http-backend, and apache2-utils to generate the password hash for authentication.

Here is my git config:

[core]
    repositoryformatversion = 0
    filemode = true
    bare = true
    sharedrepository = 1
[receive]
    denyNonFastforwards = true
[http]
    receivepack = true

And here is my nginx config:

server {
    listen       80;
    server_name  git.mydomain.com;

    # This is where the repositories live on the server
    root /srv/git;


    location ~ (/.*) {
        auth_basic "Restricted";
        auth_basic_user_file /etc/nginx/.gitpasswd;
        fastcgi_pass  unix:/var/run/fcgiwrap.socket;
        include       fastcgi_params;
        fastcgi_param SCRIPT_FILENAME     /usr/lib/git-core/git-http-backend;
        # export all repositories under GIT_PROJECT_ROOT
        fastcgi_param GIT_HTTP_EXPORT_ALL "";
        fastcgi_param GIT_PROJECT_ROOT    /srv/git;
        fastcgi_param PATH_INFO           $1;
    }
}

How to configure an open-source git repository to not need username and password when clone and pull? and is there anything else I should pay attention to in the git config for the open source repository?