change root span name for OTEL

[rajshrestha86]

The current root span name is kong. Is it possible to change it to sth else like {method} {url}. I am using kong=3.7.

[rajshrestha86]

OK I found a way to change the span name with a post-function plugin. Commenting that here if somebody needs it:

name: post-function
enabled: true
config:
  access:
    - |
      local root_span = kong.tracing.active_span()
      -- Retrieve the HTTP method and path from the request
      local method = kong.request.get_method()
      local path = kong.request.get_path()
      -- Set the span name using the method and path
      root_span.name = method .. " " .. path

[AhmedAhmedEG]

I am currently in Kong v3.13.0.0 and this method just creates an empty span with that name rather than changing the name of the root span.

[AhmedAhmedEG]

It works with this new method:-

- name: post-function
  config:
    access:
      - |
        local span = kong.tracing.active_span()

        if span then
          while span.parent do
            span = span.parent
          end

          local method = kong.request.get_method()
          local path = kong.request.get_path()
          span.name = method .. " " .. path
        end

[AhmedAhmedEG]

And don't forget to add propagation to the opentelemetry plugin:-

propagation:
  default_format: w3c
  inject:
    - w3c
  extract:
    - w3c

[AhmedAhmedEG]

Also you can expand the function to include all the headers too (Something the official OTEL SDK failed to do lol)

  - name: post-function
    config:
      access:
        - |-
          local span = kong.tracing.active_span()
          if span then
            while span.parent do
              span = span.parent
            end
            local method = kong.request.get_method()
            local path = kong.request.get_path()
            span.name = method .. " " .. path
            local req_headers = kong.request.get_headers()
            local parts = {}
            for k, v in pairs(req_headers) do
              if type(v) == "table" then
                v = table.concat(v, ", ")
              end
              table.insert(parts, '"' .. k .. '":"' .. tostring(v):gsub('"', '\\"') .. '"')
            end
            span:set_attribute("http.request.headers", "{" .. table.concat(parts, ",") .. "}")
          end
      header_filter:
        - |-
          local span = kong.tracing.active_span()
          if span then
            while span.parent do
              span = span.parent
            end
            local res_headers = kong.response.get_headers()
            local parts = {}
            for k, v in pairs(res_headers) do
              if type(v) == "table" then
                v = table.concat(v, ", ")
              end
              table.insert(parts, '"' .. k .. '":"' .. tostring(v):gsub('"', '\\"') .. '"')
            end
            span:set_attribute("http.response.headers", "{" .. table.concat(parts, ",") .. "}")
          end