fix(mypy): resolve OpenTelemetry typing issues in telemetry.py (#3943)

Fixes mypy type errors in OpenTelemetry integration:
- Add type aliases for AttributeValue and Attributes
- Add helper to filter None values from attributes (OpenTelemetry
doesn't accept None)
- Cast metric and tracer objects to proper types
- Update imports after refactoring

No functional changes.

src/llama_stack/core/telemetry/telemetry.py

@@ -6,12 +6,14 @@
 
 import os
 import threading
+from collections.abc import Mapping, Sequence
 from datetime import datetime
 from enum import Enum
 from typing import (
     Annotated,
     Any,
     Literal,
+    cast,
 )
 
 from opentelemetry import metrics, trace
@@ -30,6 +32,10 @@ from llama_stack.schema_utils import json_schema_type, register_schema
 
 ROOT_SPAN_MARKERS = ["__root__", "__root_span__"]
 
+# Type alias for OpenTelemetry attribute values (excludes None)
+AttributeValue = str | bool | int | float | Sequence[str] | Sequence[bool] | Sequence[int] | Sequence[float]
+Attributes = Mapping[str, AttributeValue]
+
 
 @json_schema_type
 class SpanStatus(Enum):
@@ -428,6 +434,13 @@ _TRACER_PROVIDER = None
 logger = get_logger(name=__name__, category="telemetry")
 
 
+def _clean_attributes(attrs: dict[str, Any] | None) -> Attributes | None:
+    """Remove None values from attributes dict to match OpenTelemetry's expected type."""
+    if attrs is None:
+        return None
+    return {k: v for k, v in attrs.items() if v is not None}
+
+
 def is_tracing_enabled(tracer):
     with tracer.start_as_current_span("check_tracing") as span:
         return span.is_recording()
@@ -456,7 +469,7 @@ class Telemetry:
                 # https://opentelemetry.io/docs/languages/sdk-configuration/otlp-exporter
                 span_exporter = OTLPSpanExporter()
                 span_processor = BatchSpanProcessor(span_exporter)
-                trace.get_tracer_provider().add_span_processor(span_processor)
+                cast(TracerProvider, trace.get_tracer_provider()).add_span_processor(span_processor)
 
                 metric_reader = PeriodicExportingMetricReader(OTLPMetricExporter())
                 metric_provider = MeterProvider(metric_readers=[metric_reader])
@@ -474,7 +487,7 @@ class Telemetry:
 
     async def shutdown(self) -> None:
         if self.is_otel_endpoint_set:
-            trace.get_tracer_provider().force_flush()
+            cast(TracerProvider, trace.get_tracer_provider()).force_flush()
 
     async def log_event(self, event: Event, ttl_seconds: int = 604800) -> None:
         if isinstance(event, UnstructuredLogEvent):
@@ -515,7 +528,7 @@ class Telemetry:
                 unit=unit,
                 description=f"Counter for {name}",
             )
-        return _GLOBAL_STORAGE["counters"][name]
+        return cast(metrics.Counter, _GLOBAL_STORAGE["counters"][name])
 
     def _get_or_create_gauge(self, name: str, unit: str) -> metrics.ObservableGauge:
         assert self.meter is not None
@@ -525,7 +538,7 @@ class Telemetry:
                 unit=unit,
                 description=f"Gauge for {name}",
             )
-        return _GLOBAL_STORAGE["gauges"][name]
+        return cast(metrics.ObservableGauge, _GLOBAL_STORAGE["gauges"][name])
 
     def _log_metric(self, event: MetricEvent) -> None:
         # Add metric as an event to the current span
@@ -560,10 +573,10 @@ class Telemetry:
             return
         if isinstance(event.value, int):
             counter = self._get_or_create_counter(event.metric, event.unit)
-            counter.add(event.value, attributes=event.attributes)
+            counter.add(event.value, attributes=_clean_attributes(event.attributes))
         elif isinstance(event.value, float):
             up_down_counter = self._get_or_create_up_down_counter(event.metric, event.unit)
-            up_down_counter.add(event.value, attributes=event.attributes)
+            up_down_counter.add(event.value, attributes=_clean_attributes(event.attributes))
 
     def _get_or_create_up_down_counter(self, name: str, unit: str) -> metrics.UpDownCounter:
         assert self.meter is not None
@@ -573,7 +586,7 @@ class Telemetry:
                 unit=unit,
                 description=f"UpDownCounter for {name}",
             )
-        return _GLOBAL_STORAGE["up_down_counters"][name]
+        return cast(metrics.UpDownCounter, _GLOBAL_STORAGE["up_down_counters"][name])
 
     def _log_structured(self, event: StructuredLogEvent, ttl_seconds: int) -> None:
         with self._lock:
@@ -601,6 +614,7 @@ class Telemetry:
                 if event.payload.parent_span_id:
                     parent_span_id = int(event.payload.parent_span_id, 16)
                     parent_span = _GLOBAL_STORAGE["active_spans"].get(parent_span_id)
+                    if parent_span:
                         context = trace.set_span_in_context(parent_span)
                 elif traceparent:
                     carrier = {
@@ -612,15 +626,17 @@ class Telemetry:
                 span = tracer.start_span(
                     name=event.payload.name,
                     context=context,
-                    attributes=event.attributes or {},
+                    attributes=_clean_attributes(event.attributes),
                 )
                 _GLOBAL_STORAGE["active_spans"][span_id] = span
 
             elif isinstance(event.payload, SpanEndPayload):
-                span = _GLOBAL_STORAGE["active_spans"].get(span_id)
+                span = _GLOBAL_STORAGE["active_spans"].get(span_id)  # type: ignore[assignment]
                 if span:
                     if event.attributes:
-                        span.set_attributes(event.attributes)
+                        cleaned_attrs = _clean_attributes(event.attributes)
+                        if cleaned_attrs:
+                            span.set_attributes(cleaned_attrs)
 
                     status = (
                         trace.Status(status_code=trace.StatusCode.OK)

src/llama_stack/providers/utils/sqlstore/sqlalchemy_sqlstore.py

@@ -4,7 +4,7 @@
 # This source code is licensed under the terms described in the LICENSE file in
 # the root directory of this source tree.
 from collections.abc import Mapping, Sequence
-from typing import Any, Literal
+from typing import Any, Literal, cast
 
 from sqlalchemy import (
     JSON,
@@ -55,17 +55,17 @@ def _build_where_expr(column: ColumnElement, value: Any) -> ColumnElement:
             raise ValueError(f"Operator mapping must have a single operator, got: {value}")
         op, operand = next(iter(value.items()))
         if op == "==" or op == "=":
-            return column == operand
+            return cast(ColumnElement[Any], column == operand)
         if op == ">":
-            return column > operand
+            return cast(ColumnElement[Any], column > operand)
         if op == "<":
-            return column < operand
+            return cast(ColumnElement[Any], column < operand)
         if op == ">=":
-            return column >= operand
+            return cast(ColumnElement[Any], column >= operand)
         if op == "<=":
-            return column <= operand
+            return cast(ColumnElement[Any], column <= operand)
         raise ValueError(f"Unsupported operator '{op}' in where mapping")
-    return column == value
+    return cast(ColumnElement[Any], column == value)
 
 
 class SqlAlchemySqlStoreImpl(SqlStore):
@@ -210,9 +210,7 @@ class SqlAlchemySqlStoreImpl(SqlStore):
                 query = query.limit(fetch_limit)
 
             result = await session.execute(query)
-            if result.rowcount == 0:
+            # Iterate directly - if no rows, list comprehension yields empty list
-                rows = []
-            else:
             rows = [dict(row._mapping) for row in result]
 
             # Always return pagination result