put `upload.lua` into:

```bash
/usr/local/opt/openresty/nginx/resty_funcs
```

post file:

```bash
$ curl --location --request POST 'localhost/upload' \
--form '=@"/Users/weli/works/task_server/src/test/resources/file_example_JPG_100kB.jpeg"'
```

nginx config

```
/usr/local/etc/openresty/nginx.conf
```

```
location /upload {
   content_by_lua_file /usr/local/opt/openresty/nginx/resty_funcs/upload.lua;
}
```

enable log:

```
error_log  /usr/local/etc/openresty/logs/error.log;
```