feat(tracing): add http.client_ip attribute (#10723)

* fix(tracing): use get_forwarded_ip instead of get_ip for peer IP

As a developer troubleshooting requests using trace data, I expect my access logs to be consistent with my traces. The access logs currently record the forwarded_ip, which tells me what my client's true ip is (assuming proper setup of trusted IPs etc). This change switches the span attribute for peer ip to use forwarded_ip as well.

* fix(tracing): add get_forwarded_ip as separate attribute

* fix(tracing): add new attribute to test case

* feat(tracing): add changelog entry

CHANGELOG.md

@@ -49,14 +49,16 @@
 - Request and response buffering options are now enabled for incoming HTTP 2.0 requests too.
   Thanks [@PidgeyBE](https://github.com/PidgeyBE) for contributing this change.
   [#10595](https://github.com/Kong/kong/pull/10595)
-  [#10204](https://github.com/Kong/kong/pull/10204)
+  [#10204](https://github.com/Kong/kong/pull/10204)  
 - Add `KONG_UPSTREAM_DNS_TIME` to `kong.ctx` so that we can record the time it takes for DNS
   resolution when Kong proxies to upstream.
   [#10355](https://github.com/Kong/kong/pull/10355)
 - Tracing: rename spans to simplify filtering on tracing backends.
   [#10577](https://github.com/Kong/kong/pull/10577)
 - Support timeout for dynamic log level
   [#10288](https://github.com/Kong/kong/pull/10288)
+- Added new span attribute `http.client_ip` to capture the client IP when behind a proxy.
+  [#10723](https://github.com/Kong/kong/pull/10723)
 
 #### Admin API
 

kong/tracing/instrumentation.lua

@@ -236,6 +236,7 @@ function _M.request(ctx)
       ["http.host"] = host,
       ["http.scheme"] = scheme,
       ["http.flavor"] = http_flavor,
+      ["http.client_ip"] = client.get_forwarded_ip(),
       ["net.peer.ip"] = client.get_ip(),
     },
   })

spec/03-plugins/37-opentelemetry/04-exporter_spec.lua

@@ -441,6 +441,7 @@ for _, strategy in helpers.each_strategy() do
         local attr = span.attributes
         sort_by_key(attr)
         assert.same({
+          { key = "http.client_ip", value = { string_value = "127.0.0.1", value = "string_value" } },
           { key = "http.flavor", value = { string_value = "1.1", value = "string_value" } },
           { key = "http.host", value = { string_value = "0.0.0.0", value = "string_value" } },
           { key = "http.method", value = { string_value = "GET", value = "string_value" } },