Python: Telemetry and observability follow-up (#833)

* updated telemetry work

* updated telemetry

* slight improvement

* updated tests

* fixes for telemetry

* fixes for mypy

* added settings setup to runner to avoid error

* streamline usage

* updated tests

* updated tests

* further refinement

* fix dumped item for otel

* removed enable_workflow_otel

* final fixes

* final fixes

* updated samples

* removed exporters

* fix tests

* fixed last import'

* fixed devui

python/packages/main/agent_framework/_telemetry.py

@@ -0,0 +1,59 @@
+# Copyright (c) Microsoft. All rights reserved.
+
+import os
+from typing import Any, Final
+
+from . import __version__ as version_info
+from ._logging import get_logger
+
+logger = get_logger()
+
+__all__ = [
+    "AGENT_FRAMEWORK_USER_AGENT",
+    "APP_INFO",
+    "USER_AGENT_KEY",
+    "USER_AGENT_TELEMETRY_DISABLED_ENV_VAR",
+    "prepend_agent_framework_to_user_agent",
+]
+
+# Note that if this environment variable does not exist, user agent telemetry is enabled.
+USER_AGENT_TELEMETRY_DISABLED_ENV_VAR = "AGENT_FRAMEWORK_USER_AGENT_DISABLED"
+IS_TELEMETRY_ENABLED = os.environ.get(USER_AGENT_TELEMETRY_DISABLED_ENV_VAR, "false").lower() not in ["true", "1"]
+
+APP_INFO = (
+    {
+        "agent-framework-version": f"python/{version_info}",  # type: ignore[has-type]
+    }
+    if IS_TELEMETRY_ENABLED
+    else None
+)
+USER_AGENT_KEY: Final[str] = "User-Agent"
+HTTP_USER_AGENT: Final[str] = "agent-framework-python"
+AGENT_FRAMEWORK_USER_AGENT = f"{HTTP_USER_AGENT}/{version_info}"  # type: ignore[has-type]
+
+
+def prepend_agent_framework_to_user_agent(headers: dict[str, Any] | None = None) -> dict[str, Any]:
+    """Prepend "agent-framework" to the User-Agent in the headers.
+
+    When user agent telemetry is disabled, through the AZURE_TELEMETRY_DISABLED environment variable,
+    the User-Agent header will not include the agent-framework information, it will be sent back as is,
+    or as a empty dict when None is passed.
+
+    Args:
+        headers: The existing headers dictionary.
+
+    Returns:
+        A new dict with "User-Agent" set to "agent-framework-python/{version}" if headers is None.
+        The modified headers dictionary with "agent-framework-python/{version}" prepended to the User-Agent.
+    """
+    if not IS_TELEMETRY_ENABLED:
+        return headers or {}
+    if not headers:
+        return {USER_AGENT_KEY: AGENT_FRAMEWORK_USER_AGENT}
+    headers[USER_AGENT_KEY] = (
+        f"{AGENT_FRAMEWORK_USER_AGENT} {headers[USER_AGENT_KEY]}"
+        if USER_AGENT_KEY in headers
+        else AGENT_FRAMEWORK_USER_AGENT
+    )
+
+    return headers