1.4.0 kong config db_export error

[cq-z]

Summary

1.4.0 kong config db_export test.yaml -v error , when have keyauth_credentials . delete ttl = true, in the file kong/plugins/key-auth/daos.lua ，it is ok

Steps To Reproduce

1. add keyauth_credentials
2. kong config db_export

Additional Details & Logs

• Kong version ($ kong version)
  1.4.0
• Kong debug-level startup logs ($ kong start --vv)

  /usr/local/share/lua/5.1/lyaml/init.lua:126: cannot dump object of type 'userdata'
  Error: 
  /usr/local/share/lua/5.1/kong/db/declarative/init.lua:278: bad argument #1 to 'write' (string expected, got nil)
  stack traceback:
  [C]: in function 'write'
  /usr/local/share/lua/5.1/kong/db/declarative/init.lua:278: in function 'export_from_db'
  /usr/local/share/lua/5.1/kong/cmd/config.lua:41: in function 'cmd_exec'
  /usr/local/share/lua/5.1/kong/cmd/init.lua:87: in function </usr/local/share/lua/5.1/kong/cmd/init.lua:87>
  [C]: in function 'xpcall'
  /usr/local/share/lua/5.1/kong/cmd/init.lua:87: in function </usr/local/share/lua/5.1/kong/cmd/init.lua:44>
  /usr/local/bin/kong:9: in function 'file_gen'
  init_worker_by_lua:49: in function <init_worker_by_lua:47>

• Kong error logs (<KONG_PREFIX>/logs/error.log)
• Kong configuration (the output of a GET request to Kong's Admin port - see https://docs.konghq.com/latest/admin-api/#retrieve-node-information)
• Operating system

[gszr]

Thanks for reporting, @cq-z. This issue has been fixed in #5192 and will be part of the upcoming 1.4.1 patch release. In the meantime, feel free to test the fix and report back. Thanks!

[cq-z]

thank you