Fix UnboundLocalError local variable 'start' referenced before assign…

…ment (#1889)

Co-authored-by: Pablo Collins <pablo.collins@gmail.com>

CHANGELOG.md

@@ -7,6 +7,16 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 
 ## Unreleased
 
+### Fixed
+
+- `opentelemetry-instrumentation-asgi` Fix UnboundLocalError local variable 'start' referenced before assignment 
+  ([#1889](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1889))
+
+### Added
+
+- Added Azure VM Resource Detector
+  ([#1904](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1904))
+
 ## Version 1.19.0/0.40b0 (2023-07-13)
 - `opentelemetry-instrumentation-asgi` Add `http.server.request.size` metric
   ([#1867](https://github.com/open-telemetry/opentelemetry-python-contrib/pull/1867))

instrumentation/opentelemetry-instrumentation-asgi/src/opentelemetry/instrumentation/asgi/__init__.py

@@ -538,6 +538,7 @@ async def __call__(self, scope, receive, send):
             receive: An awaitable callable yielding dictionaries
             send: An awaitable callable taking a single dictionary as argument.
         """
+        start = default_timer()
         if scope["type"] not in ("http", "websocket"):
             return await self.app(scope, receive, send)
 
@@ -591,7 +592,6 @@ async def __call__(self, scope, receive, send):
                     send,
                     duration_attrs,
                 )
-                start = default_timer()
 
                 await self.app(scope, otel_receive, otel_send)
         finally:

instrumentation/opentelemetry-instrumentation-asgi/tests/test_asgi_middleware.py

@@ -14,6 +14,7 @@
 
 # pylint: disable=too-many-lines
 
+import asyncio
 import sys
 import unittest
 from timeit import default_timer
@@ -796,5 +797,38 @@ async def wrapped_app(scope, receive, send):
         )
 
 
+class TestAsgiApplicationRaisingError(AsgiTestBase):
+    def tearDown(self):
+        pass
+
+    @mock.patch(
+        "opentelemetry.instrumentation.asgi.collect_custom_request_headers_attributes",
+        side_effect=ValueError("whatever"),
+    )
+    def test_asgi_issue_1883(
+        self, mock_collect_custom_request_headers_attributes
+    ):
+        """
+        Test that exception UnboundLocalError local variable 'start' referenced before assignment is not raised
+        See https://github.com/open-telemetry/opentelemetry-python-contrib/issues/1883
+        """
+        app = otel_asgi.OpenTelemetryMiddleware(simple_asgi)
+        self.seed_app(app)
+        self.send_default_request()
+        try:
+            asyncio.get_event_loop().run_until_complete(
+                self.communicator.stop()
+            )
+        except ValueError as exc_info:
+            self.assertEqual(exc_info.args[0], "whatever")
+        except Exception as exc_info:  # pylint: disable=W0703
+            self.fail(
+                "expecting ValueError('whatever'), received instead: "
+                + str(exc_info)
+            )
+        else:
+            self.fail("expecting ValueError('whatever')")
+
+
 if __name__ == "__main__":
     unittest.main()

resource/opentelemetry-resource-detector-azure-vm/LICENSE

@@ -0,0 +1,21 @@
+Copyright (c) Microsoft Corporation.
+
+MIT License
+
+Permission is hereby granted, free of charge, to any person obtaining a copy
+of this software and associated documentation files (the "Software"), to deal
+in the Software without restriction, including without limitation the rights
+to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+copies of the Software, and to permit persons to whom the Software is
+furnished to do so, subject to the following conditions:
+
+The above copyright notice and this permission notice shall be included in all
+copies or substantial portions of the Software.
+
+THE SOFTWARE IS PROVIDED *AS IS*, WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
+SOFTWARE.

resource/opentelemetry-resource-detector-azure-vm/MANIFEST.rst

@@ -0,0 +1,9 @@
+graft src
+graft tests
+global-exclude *.pyc
+global-exclude *.pyo
+global-exclude __pycache__/*
+include CHANGELOG.md
+include MANIFEST.in
+include README.rst
+include LICENSE

resource/opentelemetry-resource-detector-azure-vm/README.rst

@@ -0,0 +1,66 @@
+OpenTelemetry Resource detectors for Azure Virtual Machines
+==========================================================
+
+|pypi|
+
+.. |pypi| image:: https://badge.fury.io/py/opentelemetry-resource-detector-azure-vm.svg
+   :target: https://pypi.org/project/opentelemetry-resource-detector-azure-vm/
+
+
+This library provides custom resource detector for Azure VMs. OpenTelemetry Python has an experimental feature whereby Resource Detectors can be injected to Resource Attributes. This package includes a resource detector for Azure VM. This detector fills out the following Resource Attributes:
+ * `azure.vm.scaleset.name`
+ * `azure.vm.sku`
+ * `cloud.platform`
+ * `cloud.provider`
+ * `cloud.region`
+ * `cloud.resource_id`
+ * `host.id`
+ * `host.name`
+ * `host.type`
+ * `os.type`
+ * `os.version`
+ * `service.instance.id`
+
+ For more information, see the Semantic Conventions for Cloud Resource Attributes.
+
+Installation
+------------
+
+::
+
+    pip install opentelemetry-resource-detector-azure-vm
+
+---------------------------
+
+Usage example for `opentelemetry-resource-detector-azure-vm`
+
+.. code-block:: python
+
+    from opentelemetry import trace
+    from opentelemetry.sdk.trace import TracerProvider
+    from opentelemetry.resource.detector.azure.vm import (
+        AzureVMResourceDetector,
+    )
+    from opentelemetry.sdk.resources import get_aggregated_resources
+
+
+    trace.set_tracer_provider(
+        TracerProvider(
+            resource=get_aggregated_resources(
+                [
+                    AzureVMResourceDetector(),
+                ]
+            ),
+        )
+    )
+
+You can also enable the Azure VM Resource Detector by adding `azure_vm` to the `OTEL_EXPERIMENTAL_RESOURCE_DETECTORS` environment variable:
+
+`export OTEL_EXPERIMENTAL_RESOURCE_DETECTORS=azure_vm`
+
+References
+----------
+
+* `OpenTelemetry Project <https://opentelemetry.io/>`_
+* `Resource Detector Docs <https://opentelemetry.io/docs/specs/otel/resource/sdk/#detecting-resource-information-from-the-environment>`
+* `Cloud Semantic Conventions <https://opentelemetry.io/docs/specs/otel/resource/semantic_conventions/cloud/>`_

resource/opentelemetry-resource-detector-azure-vm/pyproject.toml

@@ -0,0 +1,50 @@
+[build-system]
+requires = ["hatchling"]
+build-backend = "hatchling.build"
+
+[project]
+name = "opentelemetry-resource-detector-container"
+dynamic = ["version"]
+description = "Container Resource Detector for OpenTelemetry"
+readme = "README.rst"
+license = "Apache-2.0"
+requires-python = ">=3.7"
+authors = [
+  { name = "OpenTelemetry Authors", email = "cncf-opentelemetry-contributors@lists.cncf.io" },
+]
+classifiers = [
+  "Development Status :: 5 - Production/Stable",
+  "Intended Audience :: Developers",
+  "License :: OSI Approved :: Apache Software License",
+  "Programming Language :: Python",
+  "Programming Language :: Python :: 3",
+  "Programming Language :: Python :: 3.7",
+  "Programming Language :: Python :: 3.8",
+  "Programming Language :: Python :: 3.9",
+  "Programming Language :: Python :: 3.10",
+  "Programming Language :: Python :: 3.11",
+]
+dependencies = [
+  "opentelemetry-sdk ~= 1.19",
+]
+
+[project.optional-dependencies]
+test = []
+
+[project.entry-points.opentelemetry_resource_detector]
+azure_vm = "opentelemetry.resource.detector.azure.vm:AzureVMResourceDetector"
+
+[project.urls]
+Homepage = "https://github.com/open-telemetry/opentelemetry-python-contrib/tree/main/resource/opentelemetry-resource-detector-azure-vm"
+
+[tool.hatch.version]
+path = "src/opentelemetry/resource/detector/azure/vm/version.py"
+
+[tool.hatch.build.targets.sdist]
+include = [
+  "/src",
+  "/tests",
+]
+
+[tool.hatch.build.targets.wheel]
+packages = ["src/opentelemetry"]

resource/opentelemetry-resource-detector-azure-vm/src/opentelemetry/resource/detector/azure/vm/__init__.py

@@ -0,0 +1,85 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+from json import loads
+from logging import getLogger
+from os import environ
+from urllib.request import Request, urlopen
+from urllib.error import URLError
+
+from opentelemetry.sdk.resources import ResourceDetector, Resource
+from opentelemetry.semconv.resource import ResourceAttributes, CloudPlatformValues, CloudProviderValues
+
+
+# TODO: Remove when cloud resource id is no longer missing in Resource Attributes
+_CLOUD_RESOURCE_ID_RESOURCE_ATTRIBUTE = "cloud.resource_id"
+_AZURE_VM_METADATA_ENDPOINT = "http://169.254.169.254/metadata/instance/compute?api-version=2021-12-13&format=json"
+_AZURE_VM_SCALE_SET_NAME_ATTRIBUTE = "azure.vm.scaleset.name"
+_AZURE_VM_SKU_ATTRIBUTE = "azure.vm.sku"
+_logger = getLogger(__name__)
+
+EXPECTED_AZURE_AMS_ATTRIBUTES = [
+    _AZURE_VM_SCALE_SET_NAME_ATTRIBUTE,
+    _AZURE_VM_SKU_ATTRIBUTE,
+    ResourceAttributes.CLOUD_PLATFORM,
+    ResourceAttributes.CLOUD_PROVIDER,
+    ResourceAttributes.CLOUD_REGION,
+    _CLOUD_RESOURCE_ID_RESOURCE_ATTRIBUTE,
+    ResourceAttributes.HOST_ID,
+    ResourceAttributes.HOST_NAME,
+    ResourceAttributes.HOST_TYPE,
+    ResourceAttributes.OS_TYPE,
+    ResourceAttributes.OS_VERSION,
+    ResourceAttributes.SERVICE_INSTANCE_ID,
+]
+
+class AzureVMResourceDetector(ResourceDetector):
+    # pylint: disable=no-self-use
+    def detect(self) -> "Resource":
+        attributes = {}
+        metadata_json = _AzureVMMetadataServiceRequestor().get_azure_vm_metadata()
+        if not metadata_json:
+            return Resource(attributes)
+        for attribute_key in EXPECTED_AZURE_AMS_ATTRIBUTES:
+            attributes[attribute_key] = _AzureVMMetadataServiceRequestor().get_attribute_from_metadata(metadata_json, attribute_key)
+        return Resource(attributes)
+
+class _AzureVMMetadataServiceRequestor:
+    def get_azure_vm_metadata(self):
+        request = Request(_AZURE_VM_METADATA_ENDPOINT)
+        request.add_header("Metadata", "True")
+        try:
+            response = urlopen(request).read()
+            return loads(response)["compute"]
+        except URLError:
+            # Not on Azure VM
+            return None
+        except Exception as e:
+            _logger.exception("Failed to receive Azure VM metadata: %s", e)
+            return None
+
+    def get_attribute_from_metadata(self, metadata_json, attribute_key):
+        ams_value = ""
+        if attribute_key == _AZURE_VM_SCALE_SET_NAME_ATTRIBUTE:
+            ams_value = metadata_json["vmScaleSetName"]
+        elif attribute_key == _AZURE_VM_SKU_ATTRIBUTE:
+            ams_value = metadata_json["sku"]
+        elif attribute_key == ResourceAttributes.CLOUD_PLATFORM:
+            ams_value = CloudPlatformValues.AZURE_VM.value
+        elif attribute_key == ResourceAttributes.CLOUD_PROVIDER:
+            ams_value = CloudProviderValues.AZURE.value
+        elif attribute_key == ResourceAttributes.CLOUD_REGION:
+            ams_value = metadata_json["location"]
+        elif attribute_key == _CLOUD_RESOURCE_ID_RESOURCE_ATTRIBUTE:
+            ams_value = metadata_json["resourceId"]
+        elif attribute_key == ResourceAttributes.HOST_ID or \
+            attribute_key == ResourceAttributes.SERVICE_INSTANCE_ID:
+            ams_value = metadata_json["vmId"]
+        elif attribute_key == ResourceAttributes.HOST_NAME:
+            ams_value = metadata_json["name"]
+        elif attribute_key == ResourceAttributes.HOST_TYPE:
+            ams_value = metadata_json["vmSize"]
+        elif attribute_key == ResourceAttributes.OS_TYPE:
+            ams_value = metadata_json["osType"]
+        elif attribute_key == ResourceAttributes.OS_VERSION:
+            ams_value = metadata_json["version"]
+        return ams_value

resource/opentelemetry-resource-detector-azure-vm/src/opentelemetry/resource/detector/azure/vm/version.py

@@ -0,0 +1,4 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.
+
+__version__ = "0.41b0.dev"

resource/opentelemetry-resource-detector-azure-vm/tests/__init__.py

@@ -0,0 +1,2 @@
+# Copyright (c) Microsoft Corporation. All rights reserved.
+# Licensed under the MIT License.