Python: improve .env handling and observability samples (#4032)

* Python: improve .env precedence and observability samples

- Switch load_settings to explicit precedence: overrides -> explicit .env -> environment -> defaults\n- Raise when env_file_path is provided but missing\n- Update settings docs and tests for new behavior\n- Refresh observability samples and README guidance for env loading options\n\nCloses #3864\n\nCo-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* fixed some imports

* Fix load_settings CI regressions

Allow explicit env_file_path values that exist but are not regular files (for example /dev/null) by checking path existence before dotenv parsing, and restore a dict accumulator with typed return cast to satisfy mypy.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

* Avoid implicit dotenv in observability

Only load dotenv in observability helpers when env_file_path is explicitly provided, and remove test os.devnull workarounds that are no longer necessary.

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>

---------

Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
This commit is contained in:
Eduard van Valkenburg
2026-02-18 11:18:52 +00:00
committed by GitHub
co-authored by Copilot
parent f900febb6f
commit 534e5f5bf7
41 changed files with 250 additions and 221 deletions
@@ -1,4 +1,4 @@
# Agent Framework Python Observability
# Agent Framework Observability
This sample folder shows how a Python application can be configured to send Agent Framework observability data to the Application Performance Management (APM) vendor(s) of your choice based on the OpenTelemetry standard.
@@ -222,7 +222,15 @@ This folder contains different samples demonstrating how to use telemetry in var
1. Open a terminal and navigate to this folder: `python/samples/02-agents/observability/`. This is necessary for the `.env` file to be read correctly.
2. Create a `.env` file if one doesn't already exist in this folder. Please refer to the [example file](./.env.example).
> **Note**: You can start with just `ENABLE_INSTRUMENTATION=true` and add `OTEL_EXPORTER_OTLP_ENDPOINT` or other configuration as needed. If no exporters are configured, you can set `ENABLE_CONSOLE_EXPORTERS=true` for console output.
3. Activate your python virtual environment, and then run `python configure_otel_providers_with_env_var.py` or others.
3. Choose one environment-loading approach:
- **A. Sample-managed loading (current samples):** run from this folder so the sample's `load_dotenv()` call can find `.env`.
- **B. Shell/IDE-managed environment:** set/export environment variables directly, or use an IDE run configuration that injects env vars / `.env`.
- **C. Explicit env file in code:** pass `env_file_path` to APIs like `configure_otel_providers(env_file_path=".env")` (or your own settings loader path).
- **D. CLI-managed env file:** run with `uv` and pass the file explicitly, for example:
`uv run --env-file=.env python configure_otel_providers_with_env_var.py`
4. Activate your python virtual environment, then run a sample (for example `python configure_otel_providers_with_env_var.py`).
> If you do manual provider setup (e.g., Azure Monitor), call `enable_instrumentation()` to turn on Agent Framework telemetry code paths; if you want Agent Framework to configure exporters/providers for you, call `configure_otel_providers(...)`.
> Each sample will print the Operation/Trace ID, which can be used later for filtering logs and traces in Application Insights or Aspire Dashboard.