$ curl -F "file=@sample.txt" https://localhost:8443/upload --http2 --insecure

http {

    server {
        listen        8088;
        location /upload {
            content_by_lua '
                local upload = require "resty.upload"
                local cjson = require "cjson"

                local chunk_size = 5 -- should be set to 4096 or 8192
                                     -- for real-world settings

                local form, err = upload:new(chunk_size)
                if not form then
                    ngx.log(ngx.ERR, "failed to new upload: ", err)
                    ngx.exit(500)
                end

                form:set_timeout(1000) -- 1 sec

                while true do
                    local typ, res, err = form:read()
                    if not typ then
                        ngx.say("failed to read: ", err)
                        return
                    end

                    ngx.say("read: ", cjson.encode({typ, res}))

                    if typ == "eof" then
                        break
                    end
                end

                local typ, res, err = form:read()
                ngx.say("read: ", cjson.encode({typ, res}))
            ';
        }
    }

    server {
        listen          8443 ssl http2 default_server;
        server_name     foo.com;
        ssl_certificate          server.crt;
        ssl_certificate_key  server.key;

        location / {
            proxy_pass               http://backend;
            proxy_request_buffering  off;
            proxy_set_header Host   $host;
            proxy_set_header         X-Real-IP $remote_addr;
            proxy_http_version       1.1;
            proxy_set_header         Connection "";
        }
    }

    upstream backend {
        server localhost:8088;
        keepalive 128;
    }
}