Customize OpenTelemetry spans as a developer

The OpenTelemetry plugin is built on top of the Kong Gateway tracing PDK.

It’s possible to customize the spans and add your own spans through the universal tracing PDK.

Create a custom span

The following is an example for adding a custom span using Kong Gateway’s serverless plugin:

1. Create a file named custom-span.lua with the following content:

      -- Modify the root span
      local root_span = kong.tracing.active_span()
      root_span:set_attribute("custom.attribute", "custom value")
   
      -- Create a custom span
      local span = kong.tracing.start_span("custom-span")
   
      -- Append attributes
      span:set_attribute("custom.attribute", "custom value")
         
      -- Close the span
      span:finish()
   

2. Apply the Lua code using the post-function plugin using a cURL file upload:

    curl -i -X POST http://localhost:8001/plugins \
      -F "name=post-function" \
      -F "config.access[1]=@custom-span.lua"
   
    HTTP/1.1 201 Created
    ...
   

More information

• Troubleshooting the OpenTelemetry plugin
• How logging works in the OpenTelemetry plugin
• How tracing works in the OpenTelemetry plugin