refactor(span): Use of thekind parameter.

To maintain OpenTelemetry API compliance, this commit changes the
`InstanaSpan` to use OTel's `SpanKind` as a parameter during the span
creation.

This commit fixes #813.

Signed-off-by: Paulo Vital <paulo.vital@ibm.com>

Author: pvital

src/instana/span/readable_span.py

@@ -1,8 +1,9 @@
 # (c) Copyright IBM Corp. 2024
 
 from time import time_ns
-from typing import Optional, Sequence, List
+from typing import List, Optional, Sequence
 
+from opentelemetry.trace import SpanKind
 from opentelemetry.trace.status import Status, StatusCode
 from opentelemetry.util import types
 
@@ -56,6 +57,7 @@ def __init__(
         events: Sequence[Event] = [],
         status: Optional[Status] = Status(StatusCode.UNSET),
         stack: Optional[List] = None,
+        kind: SpanKind = SpanKind.INTERNAL,
     ) -> None:
         self._name = name
         self._context = context
@@ -74,6 +76,7 @@ def __init__(
         self.synthetic = False
         if context.synthetic:
             self.synthetic = True
+        self._kind = kind
 
     @property
     def name(self) -> str:
@@ -110,3 +113,7 @@ def status(self) -> Status:
     @property
     def parent_id(self) -> int:
         return self._parent_id
+
+    @property
+    def kind(self) -> SpanKind:
+        return self._kind

src/instana/span/span.py

@@ -27,6 +27,7 @@
     INVALID_SPAN_ID,
     INVALID_TRACE_ID,
     Span,
+    SpanKind,
 )
 from opentelemetry.trace.span import NonRecordingSpan
 from opentelemetry.trace.status import Status, StatusCode
@@ -52,6 +53,7 @@ def __init__(
         attributes: types.Attributes = {},
         events: Sequence[Event] = [],
         status: Optional[Status] = Status(StatusCode.UNSET),
+        kind: SpanKind = SpanKind.INTERNAL,
     ) -> None:
         super().__init__(
             name=name,
@@ -62,7 +64,7 @@ def __init__(
             attributes=attributes,
             events=events,
             status=status,
-            # kind=kind,
+            kind=kind,
         )
         self._span_processor = span_processor
         self._lock = Lock()
@@ -190,7 +192,7 @@ def _readable_span(self) -> ReadableSpan:
             events=self.events,
             status=self.status,
             stack=self.stack,
-            # kind=self.kind,
+            kind=self.kind,
         )
 
     def end(self, end_time: Optional[int] = None) -> None:

src/instana/tracer.py

@@ -131,6 +131,7 @@ def start_span(
             parent_id=(None if parent_context is None else parent_context.span_id),
             start_time=(time.time_ns() if start_time is None else start_time),
             attributes=attributes,
+            kind=kind,
             # events: Sequence[Event] = None,
         )