Core: PID file writing synchronization. Now, ngx_daemon() does not call exit() in the parent process immediately, but instead waits for the child process to signal it actually started (and wrote the PID file if configured to). This ensures that the PID file already exists when the parent process exits. To make sure that signal handlers won't cause unexpected logging in the parent process if the child process dies (for example, due to errors when writing the PID file), ngx_init_signals() is moved to the child process. This resolves "PID file ... not readable (yet?) after start" and "Failed to parse PID from file..." errors as observed with systemd. Note that the errors observed are considered to be a bug in systemd, which isn't able to work properly with traditional Unix daemons. Still, the workaround is implemented to make sure there will be no OS vendor patches trying to address this.

uwsgi_param  QUERY_STRING       $query_string;
uwsgi_param  REQUEST_METHOD     $request_method;
uwsgi_param  CONTENT_TYPE       $content_type;
uwsgi_param  CONTENT_LENGTH     $content_length;

uwsgi_param  REQUEST_URI        $request_uri;
uwsgi_param  PATH_INFO          $document_uri;
uwsgi_param  DOCUMENT_ROOT      $document_root;
uwsgi_param  SERVER_PROTOCOL    $server_protocol;
uwsgi_param  REQUEST_SCHEME     $scheme;
uwsgi_param  HTTPS              $https if_not_empty;

uwsgi_param  REMOTE_ADDR        $remote_addr;
uwsgi_param  REMOTE_PORT        $remote_port;
uwsgi_param  SERVER_PORT        $server_port;
uwsgi_param  SERVER_NAME        $server_name;