Nginx config for unbundling GitLab with SSL

Here is my configuration for GitLab with unbundled nginx (via passenger) and working SSL (via letsencrypt).

GitLab was running on host with another web applications, so my main target was to use only one nginx instance on 80 and 443 ports. As we know letsencrypt allows to secure only this two ports, so it is impossible to setup with their certs another SSL secured nginx on different ports.

upstream gitlab-workhorse {
  server unix://var/opt/gitlab/gitlab-workhorse/socket fail_timeout=0;
}

server {
  listen 443;
  server_name $GITHOST;

  ssl_certificate /etc/letsencrypt/live/$GITHOST/fullchain.pem; # managed by Certbot
  ssl_certificate_key /etc/letsencrypt/live/$GITHOST/privkey.pem; # managed by Certbot
  include /etc/letsencrypt/options-ssl-nginx.conf; # managed by Certbot
  ssl_dhparam /etc/letsencrypt/ssl-dhparams.pem; # managed by Certbot

  # server_tokens off;
  root /opt/gitlab/embedded/service/gitlab-rails/public;

  client_max_body_size 250m;

  access_log  /var/log/nginx/access_git.log;
  error_log   /var/log/nginx/error_git.log;

  # Ensure Passenger uses the bundled Ruby version
  passenger_ruby /opt/gitlab/embedded/bin/ruby;

  # Correct the $PATH variable to included packaged executables
  passenger_env_var PATH "/opt/gitlab/bin:/opt/gitlab/embedded/bin:/usr/local/bin:/usr/bin:/bin";

  # Make sure Passenger runs as the correct user and group to
  # prevent permission issues
  passenger_user git;
  passenger_group git;

  # Enable Passenger & keep at least one instance running at all times
  passenger_enabled on;
  passenger_min_instances 1;

  location ~ ^/[\w\.-]+/[\w\.-]+/(info/refs|git-upload-pack|git-receive-pack)$ {
    # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
    error_page 418 = @gitlab-workhorse;
    return 418;
  }

  location ~ ^/[\w\.-]+/[\w\.-]+/repository/archive {
    # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
    error_page 418 = @gitlab-workhorse;
    return 418;
  }

  location ~ ^/api/v3/projects/.*/repository/archive {
    # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
    error_page 418 = @gitlab-workhorse;
    return 418;
  }

  # Build artifacts should be submitted to this location
  location ~ ^/[\w\.-]+/[\w\.-]+/builds/download {
      client_max_body_size 0;
      # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
      error_page 418 = @gitlab-workhorse;
      return 418;
  }

  # Build artifacts should be submitted to this location
  location ~ /ci/api/v1/builds/[0-9]+/artifacts {
      client_max_body_size 0;
      # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
      error_page 418 = @gitlab-workhorse;
      return 418;
  }

  # Build artifacts should be submitted to this location
  location ~ /api/v4/jobs/[0-9]+/artifacts {
      client_max_body_size 0;
      # 'Error' 418 is a hack to re-use the @gitlab-workhorse block
      error_page 418 = @gitlab-workhorse;
      return 418;
  }


  # For protocol upgrades from HTTP/1.0 to HTTP/1.1 we need to provide Host header if its missing
  if ($http_host = "") {
  # use one of values defined in server_name
    set $http_host_with_default "$GITHOST";
  }

  if ($http_host != "") {
    set $http_host_with_default $http_host;
  }


  ## location @gitlab-workhorse {
  location / {

    ## https://github.com/gitlabhq/gitlabhq/issues/694
    ## Some requests take more than 30 seconds.
    proxy_read_timeout      3600;
    proxy_connect_timeout   300;
    proxy_redirect          off;

    # Do not buffer Git HTTP responses
    proxy_buffering off;

    proxy_set_header    Host                $http_host_with_default;
    proxy_set_header    X-Real-IP           $remote_addr;
    proxy_set_header    X-Forwarded-For     $proxy_add_x_forwarded_for;
    proxy_set_header    X-Forwarded-Proto   $scheme;

    proxy_pass http://gitlab-workhorse;

    ## The following settings only work with NGINX 1.7.11 or newer
    #
    ## Pass chunked request bodies to gitlab-workhorse as-is
    # proxy_request_buffering off;
    # proxy_http_version 1.1;
  }

  ## Enable gzip compression as per rails guide:
  ## http://guides.rubyonrails.org/asset_pipeline.html#gzip-compression
  ## WARNING: If you are using relative urls remove the block below
  ## See config/application.rb under "Relative url support" for the list of
  ## other files that need to be changed for relative url support
  location ~ ^/(assets)/ {
    root /opt/gitlab/embedded/service/gitlab-rails/public;
    gzip_static on; # to serve pre-gzipped version
    expires max;
    add_header Cache-Control public;
  }

  error_page 502 /502.html;
}

server {
    if ($host = $GITHOST) {
        return 301 https://$host$request_uri;
    } 


    listen 80;
    server_name $GITHOST;
    return 404; 
}