Current Behavior

When opentelemetry metadata trace_id_source is set to x-request-id and the request-id plugin is enabled (default UUID), requests with X-Request-Id present trigger a Lua runtime error. The request fails and logs show a bad argument error.

Related issues that might be similar:

• help request: Unable to connect to OpenTelemetry #11969
• bug: Trouble with opentelemetry plugin #10389

Expected Behavior

The plugin should validate that x-request-id is a 32-hex trace_id (16 bytes). If invalid (UUID with hyphens, ksuid/nanoid/range_id, empty string, etc.), it should fall back to random trace_id or ignore the header. It should never crash.

We can also consider supporting the generation of a valid trace ID in the request-id plugin.

Error Logs

2025-02-14 14:10:24 2025/02/14 14:10:24 [error] 53#53: *537 lua entry thread aborted: runtime error: bad argument #1 to '?' (invalid value)
2025-02-14 14:10:24 stack traceback:
2025-02-14 14:10:24 coroutine 0:
2025-02-14 14:10:24 [C]: in function 'gsub'
2025-02-14 14:10:24 ...s/share/lua/5.1/opentelemetry/trace/exporter/encoder.lua:22: in function 'hex2bytes'
2025-02-14 14:10:24 ...s/share/lua/5.1/opentelemetry/trace/exporter/encoder.lua:66: in function 'for_otlp'
2025-02-14 14:10:24 ...deps/share/lua/5.1/opentelemetry/trace/exporter/otlp.lua:102: in function 'export_spans'
2025-02-14 14:10:24 ...are/lua/5.1/opentelemetry/trace/batch_span_processor.lua:45: in function 'process_batches'
2025-02-14 14:10:24 ...are/lua/5.1/opentelemetry/trace/batch_span_processor.lua:77: in function

Steps to Reproduce

1. Enable the request-id plugin (default header X-Request-Id, algorithm uuid).
2. Set opentelemetry plugin metadata trace_id_source to x-request-id.
3. Send a request
4. Observe the runtime error and failed request.

Environment

• APISIX version (run apisix version):
• Operating system (run uname -a):
• OpenResty / Nginx version (run openresty -V or nginx -V):
• etcd version, if relevant (run curl http://127.0.0.1:9090/v1/server_info):
• APISIX Dashboard version, if relevant:
• Plugin runner version, for issues related to plugin runners:
• LuaRocks version, for installation issues (run luarocks --version):