Fix server.port to be not required on HTTP server spans when server.address is not set

CHANGELOG.md

@@ -24,6 +24,8 @@ release.
 - Remove `thread.daemon`, and introduce `jvm.thread.daemon` instead.
   Introduce `jvm.thread.state` attribute and add it to `jvm.thread.count` metric.
   ([#297](https://github.com/open-telemetry/semantic-conventions/pull/297))
+- Fix `server.port` to be not required when `server.address` is not set.
+  ([#429](https://github.com/open-telemetry/semantic-conventions/pull/429))
 
 ### Features
 

docs/http/http-spans.md

@@ -390,7 +390,7 @@ MUST NOT include the port identifier.
   [X-Forwarded-Host](https://developer.mozilla.org/docs/Web/HTTP/Headers/X-Forwarded-Host), or a similar header.
 - Port identifier of the `Host` header.
 
-**[6]:** If not default (`80` for `http` scheme, `443` for `https`).
+**[6]:** If `server.address` is set and the port is not default (`80` for `http` scheme, `443` for `https`).
 
 **[7]:** When missing, the value is assumed to be `/`
 

model/http-common.yaml

@@ -97,7 +97,7 @@ groups:
             [X-Forwarded-Host](https://developer.mozilla.org/docs/Web/HTTP/Headers/X-Forwarded-Host), or a similar header.
           - Port identifier of the `Host` header.
         requirement_level:
-          conditionally_required: If not default (`80` for `http` scheme, `443` for `https`).
+          conditionally_required: If `server.address` is set and the port is not default (`80` for `http` scheme, `443` for `https`).
       - ref: url.scheme
         requirement_level: required
         examples: ["http", "https"]