Error occurs on endpoints when `tags` parameter is empty

[hutchic]

Is there an existing issue for this?

• [X] I have searched the existing issues

Kong version ($ kong version)

Kong 2.7.1

Current Behavior

Requests with ?tags= to the admin api results in a 500 error

curl -X GET 'http://localhost:8001/ca_certificates?tags='

Kong logs

• stringx.lua:32: argument 1 expected a 'string', got a 'userdata'

2024/08/29 05:18:38 [error] 1335#0: *10353 [lua] api_helpers.lua:540: handle_error(): /usr/local/share/lua/5.1/lapis/application.lua:440: /usr/local/share/lua/5.1/pl/stringx.lua:32: argument 1 expected a 'string', got a 'userdata'
stack traceback:
   [C]: in function 'error'
   /usr/local/share/lua/5.1/pl/utils.lua:291: in function 'assert_arg'
   /usr/local/share/lua/5.1/pl/stringx.lua:32: in function 'assert_string'
   /usr/local/share/lua/5.1/pl/stringx.lua:194: in function 'split'
   /usr/local/share/lua/5.1/kong/api/endpoints.lua:166: in function 'extract_options'
   /usr/local/share/lua/5.1/kong/api/endpoints.lua:209: in function 'page_collection'
   /usr/local/share/lua/5.1/kong/api/endpoints.lua:319: in function 'fn'
   /usr/local/share/lua/5.1/kong/api/api_helpers.lua:311: in function </usr/local/share/lua/5.1/kong/api/api_helpers.lua:289>

stack traceback:
   [C]: in function 'error'
   /usr/local/share/lua/5.1/lapis/application.lua:440: in function 'handler'
   /usr/local/share/lua/5.1/lapis/application.lua:186: in function 'resolve'
   /usr/local/share/lua/5.1/lapis/application.lua:217: in function </usr/local/share/lua/5.1/lapis/application.lua:215>
   [C]: in function 'xpcall'
   /usr/local/share/lua/5.1/lapis/application.lua:215: in function 'dispatch'
   /usr/local/share/lua/5.1/lapis/nginx.lua:231: in function 'serve'
   /usr/local/share/lua/5.1/kong/init.lua:1867: in function 'admin_content'
   content_by_lua(nginx-kong.conf:333):2: in main chunk, client: 172.19.0.1, server: kong_admin, request: "GET /ca_certificates?tags= HTTP/1.1", host: "localhost:8001"
172.19.0.1 - - [29/Aug/2024:05:18:39 +0000] "GET /ca_certificates?tags= HTTP/1.1" 500 42 "-" "curl/7.81.0"

Expected Behavior

The API should return a valid response, such as an empty list of CA certificates or a relevant error message indicating that the tags parameter is required, if applicable. The system should handle empty tags gracefully without causing an internal server error.

Steps To Reproduce

run kong run the curl curl -X GET 'http://localhost:8001/ca_certificates?tags='

Anything else?

No response

[chobits]

For kong master, I could still reproduce it:

xc ~ $ curl -X GET 'http://localhost:8001/ca_certificates?tags=1'
{"next":null,"data":[]}

xc ~ $ curl -X GET 'http://localhost:8001/ca_certificates?tags='
{"message":"An unexpected error occurred"}

xc ~ $ curl -X GET 'http://localhost:8001/ca_certificates'
{"next":null,"data":[]}xc ~ $

and it reported the runtime error in admin error log file:

2024/09/02 10:30:14 [error] 96780#0: *647 [lua] api_helpers.lua:541: handle_error(): ...l-bin/build/kong-dev/share/lua/5.1/lapis/application.lua:440:
 ...ng/bazel-bin/build/kong-dev/share/lua/5.1/pl/stringx.lua:32: 
     argument 1 expected a 'string', got a 'userdata'
stack traceback:
        [C]: in function 'error'
        ...kong/bazel-bin/build/kong-dev/share/lua/5.1/pl/utils.lua:291: in function 'assert_arg'
        ...ng/bazel-bin/build/kong-dev/share/lua/5.1/pl/stringx.lua:32: in function 'assert_string'
        ...ng/bazel-bin/build/kong-dev/share/lua/5.1/pl/stringx.lua:194: in function 'split'
        ./kong/api/endpoints.lua:167: in function 'extract_options'
        ./kong/api/endpoints.lua:210: in function 'page_collection'
        ./kong/api/endpoints.lua:320: in function 'fn'
        ./kong/api/api_helpers.lua:312: in function <./kong/api/api_helpers.lua:290>

[nowNick]

Internal ticket tracking code: KAG-5496