nginx.upload.conf

lua_package_path "/opt/script/?.lua;;";

server {
  client_max_body_size 50m;
  listen 8070;
  server_name  _;
  add_header Access-Control-Allow-Origin *;
  add_header Access-Control-Allow-Methods POST;

  location /post_upload {
    content_by_lua_file /opt/script/post_upload.lua;
    # lua_code_cache off;
  }

  # Upload form should be submitted to this location
  location /upload {
    # Pass altered request body to this location
    upload_pass   /post_upload;

    # Store files to this directory
    # The directory is hashed, subdirectories 0 1 2 3 4 5 6 7 8 9 should exist
    upload_store /opt/upload 2 2;

    # Allow uploaded files to be read only by user
    upload_store_access user:r;

    # Set specified fields in request body
    upload_set_form_field $upload_field_name.name "$upload_file_name";
    upload_set_form_field $upload_field_name.content_type "$upload_content_type";
    upload_set_form_field $upload_field_name.path "$upload_tmp_path";

    # Inform backend about hash and size of a file
    upload_aggregate_form_field "$upload_field_name.md5" "$upload_file_md5";
    upload_aggregate_form_field "$upload_field_name.size" "$upload_file_size";

    upload_pass_form_field "^.*$";

    upload_cleanup 400 404 499 500-505;
  }

  location /img {
    alias /opt/upload/;
    autoindex on;
  }

}