opencensus-extension-azure-functions 1.0.0

OpenCensus extension for Azure Functions

Installation

pip install opencensus-extension-azure-functions

Prerequisites

Install azure-functions-core-tools or Azure Functions vscode-extension.

How To Use In Python Functions

1. Use func init --python or VSCode Extensions Blade -> Azure -> Functions -> Create New Project... to create a Python function app.

2. Use func new -a anonymous -t HttpTrigger -n HttpTrigger to create an anonymous Http trigger in your function app. If you’re using VSCode, the project creation wizard will guide you through the same process.

3. Include opencensus-extension-azure-functions and requests to your requirements.txt.

4. In local.settings.json, add new settings "PYTHON_ENABLE_WORKER_DEPENDENCIES": "1" and "APPLICATIONINSIGHTS_CONNECTION_STRING": "InstrumentationKey=aaaaaaaa-bbbb-cccc-dddd-eeeeeeeeeeee". You can acquire your appinsights instrumentation key from your Azure Application Insights resource.

5. Set up a virtual environment for your local development

   1. Create a virtual environment with py -3.7 -m venv .venv in Windows or python3.7 -m venv .venv in Unix-like systems.

   2. Activate the virtual environment with .venv\Scripts\Activate.ps1 in Windows PowerShell or source .venv/bin/activate in Unix-like systems.

6. Change the HTTP trigger file in <project_root>/HttpTrigger/__init__.py to enable the OpenCensus tracing integration.

import json
import logging

from opencensus.extension.azure.functions import OpenCensusExtension
logger = logging.getLogger('HttpTriggerLogger')

OpenCensusExtension.configure()

def main(req, context):
    logger.info('Executing HttpTrigger with OpenCensus extension')

    # You must use context.tracer to create spans
    with context.tracer.span("parent"):
        logger.info('Message from HttpTrigger')

    return json.dumps({
        'method': req.method,
        'ctx_func_name': context.function_name,
        'ctx_func_dir': context.function_directory,
        'ctx_invocation_id': context.invocation_id,
        'ctx_trace_context_Traceparent': context.trace_context.Traceparent,
        'ctx_trace_context_Tracestate': context.trace_context.Tracestate,
    })

7. Run it in your local development environment by func host start --verbose in Core Tools or hitting F5 in VSCode.

8. You should now be able to check the trace information in your Application Insight -> Investigate -> Application Map.

To use Opencensus Python Extensions in other scenarios, please visit our example folder

References

• OpenCensus Project

• OpenCensus Python SDK

• Python Worker Extension Interface

• Author Your First Worker Extension