I am trying to setup a git server with stagit for the front end, git-http-backend for the back and using nginx between everything. I've found a config that works on my server in this answer (and by works, I mean nginx will serve html to any connection through a web browser, but lets me clone a repository if I use git clone https://git.website.com/test.git.

The problem I'm having, is that when I push this repository (whether that be from the server itself, or from my local computer) with an origin of https://git.website.com/test.git I receive a 403 error and I'm not sure why. Any ideas?

server {
    listen 80;
    listen [::]:80;

    listen 443 ssl;
    listen [::]:443 ssl;

    ssl_certificate /etc/ssl/ssl-bundle.crt;
    ssl_certificate_key /etc/ssl/private/ssl-private.key;

    root /srv/git;

    index index.html index.htm index.nginx-debian.html;

    access_log /var/log/nginx/git.access.log;
    error_log /var/log/nginx/git.error.log;
    gzip off;

    location / {
        try_files $uri $uri/ =404;
    }

    # static repo files for cloning over https
    location ~ ^.*/objects/([0-9a-f]+/[0-9a-f]+|pack/pack-[0-9a-f]+.(pack|idx))$ {
        root /srv/git;
    }

    # requests that need to go to git-http-backend
    location ~ ^.*/(HEAD|info/refs|objects/info/.*|git-(upload|receive)-pack)$ {
        root /srv/git;

        fastcgi_pass  unix:/var/run/fcgiwrap.socket;
        fastcgi_param SCRIPT_FILENAME   /usr/lib/git-core/git-http-backend;
        fastcgi_param PATH_INFO         $uri;
        fastcgi_param GIT_PROJECT_ROOT  $document_root;
        fastcgi_param GIT_HTTP_EXPORT_ALL "";
        fastcgi_param REMOTE_USER $remote_user;
        include fastcgi_params;
    }   
}

I only started trying to use git-http-backend about two hours ago with multiple configs. It seems very difficult to get http to serve webpages normally but also allow for git to clone/push. Using a config as found here resulted in empty 200 OK responses...

After much trial and error I've taken the config from this answer and modified it to give me the following location rules:

location / {
    if ($arg_service = git-receive-pack) {
        rewrite (/.*) /git_write/$1 last;
    }

    if ($uri ~ ^/.*/git-receive-pack$) {
        rewrite (/.*) /git_write/$1 last;
    }

    if ($arg_service = git-upload-pack) {
        rewrite (/.*) /git_read/$1 last;
    }

    if ($uri ~ ^/.*/git-upload-pack$) {
        rewrite (/.*) /git_read/$1 last;
    }
}

# pass PHP scripts to FastCGI server
location ~ \.php$ {
    include snippets/fastcgi-php.conf;
    fastcgi_pass unix:/run/php/php7.3-fpm.sock;
}

location ~ /git_read/(.*) {
    include git-http-backend.conf;
}

# require auth to upload
location ~ /git_write/(.*) {
    auth_basic "Pushing to Git repositories is restricted";
    auth_basic_user_file /etc/nginx/htpasswd;
    include git-http-backend.conf;
}

Where /etc/nginx/git-http-backend.conf reads:

fastcgi_pass unix:/var/run/fcgiwrap.socket;
include fastcgi_params;
fastcgi_param SCRIPT_FILENAME /usr/lib/git-core/git-http-backend;
fastcgi_param GIT_HTTP_EXPORT_ALL "";
fastcgi_param GIT_PROJECT_ROOT /srv/git;
fastcgi_param PATH_INFO $1;
fastcgi_param REMOTE_USER $remote_user;

Problem solved.