This commit completes the core functionality of the iperf3 exporter and adds flexible log level configuration.
Key changes:
- Added command-line (`--log-level`) and environment variable (`LOG_LEVEL`) options to configure the logging level.
- Implemented the main test orchestration loop (`main_loop`) which:
- Discovers iperf3 server pods via the Kubernetes API.
- Periodically runs iperf3 tests (TCP/UDP) between the exporter pod and discovered server pods.
- Avoids self-testing.
- Uses configurable test intervals, server ports, and protocols.
- Requires `SOURCE_NODE_NAME` to be set.
- Refined the `parse_and_publish_metrics` function to:
- Accurately parse iperf3 results for bandwidth, jitter, packets, and lost packets.
- Set `IPERF_TEST_SUCCESS` metric (0 for failure, 1 for success).
- Zero out all relevant metrics for a given path upon test failure to prevent stale data.
- Handle UDP-specific metrics correctly, zeroing them for TCP tests.
- Improved robustness in accessing iperf3 result attributes.
- Updated the main execution block to initialize logging, start the Prometheus HTTP server, and invoke the main loop.
- Added comprehensive docstrings and inline comments throughout `exporter/exporter.py` for improved readability and maintainability.
These changes align the exporter's implementation with the details specified in the design document (docs/DESIGN.MD).