Python

Start with opentelemetry-instrument#

Python apps send to WizeLens through OpenTelemetry auto-instrumentation. It traces FastAPI, Flask, Django, SQLAlchemy, psycopg, sqlite3, requests, httpx, and more, with no code change.

pip install wizelens
opentelemetry-bootstrap -a install          # instrumentations for the libraries you use
OTEL_SERVICE_NAME=orders-api opentelemetry-instrument uvicorn app:app

opentelemetry-instrument finds the wizelens package on its own: it is an OpenTelemetry distro and configurator. Do not also install opentelemetry-distro. If you must, set OTEL_PYTHON_DISTRO=wizelens and OTEL_PYTHON_CONFIGURATOR=wizelens.

The insights work on what the instrumentations send: N+1 queries, N+1 HTTP calls, slow queries, and database waits.

What the package adds#

	Plain OpenTelemetry	With wizelens
Where it sends	You set OTEL_EXPORTER_OTLP_ENDPOINT	WIZELENS_HUB, else http://localhost:5960
Sampling	Head sampling: errors can be dropped	Keeps every trace with an error or a slow span
SQL parameters	None, so no duplicate-query insight	On every DB-API driver and SQLAlchemy, sensitive names redacted
connection.execute() (sqlite3, psycopg 3)	Not traced	Traced
Logs	Off unless you turn them on	Every logging line, with its trace
Request headers	Off	On, with secrets redacted
FastAPI	A span per message sent	One server span per request

Anything you set yourself with OTEL_* wins.

Request and response bodies#

Add one line for your framework, then set WIZELENS_CAPTURE_BODY=true:

Framework	Code
FastAPI, Starlette	app.add_middleware(WizeLensMiddleware) (from wizelens import WizeLensMiddleware)
Flask	capture_flask(app) (from wizelens import capture_flask)
Django	Add "wizelens.frameworks.WizeLensDjangoMiddleware" to MIDDLEWARE, after the OpenTelemetry one

Text and JSON bodies are kept, up to 16 KB each. JSON keys that look like secrets are redacted.

Without opentelemetry-instrument#

import wizelens

wizelens.configure(service_name="orders-api")   # before your app imports its libraries

Then instrument libraries yourself, for example FastAPIInstrumentor.instrument_app(app). For a driver WizeLens does not patch, put the parameters on the span with wizelens.record_parameters(params).

Settings#

Variable	Default	What it does
WIZELENS_HUB	http://localhost:5960	Hub or cloud address
WIZELENS_HUB_TOKEN	none	Hub token or cloud ingest key
WIZELENS_PROJECT	none	Project on a shared hub
WIZELENS_SAMPLE_RATE	1	Share of traces kept. See Sampling
WIZELENS_KEEP_SLOW_MS	1000	Keep traces with a span this slow at any rate (off for none)
WIZELENS_KEEP_ERRORS	true	Keep traces with an error at any rate
WIZELENS_CAPTURE_BODY	false	Request and response bodies
WIZELENS_CAPTURE_SQL_PARAMETERS	true	SQL parameters
WIZELENS_CAPTURE_LOGS	true	logging lines
WIZELENS_REDACT_KEYS	none	More key fragments to redact, comma-separated
WIZELENS_ENABLED	true	false turns OpenTelemetry off

A runnable sample#

samples/python-fastapi is a FastAPI service with SQLite. GET /orders shows N+1 queries, a duplicate query, and N+1 HTTP calls to the Go sample; GET /report shows a slow query and a database wait; GET /fail shows an error with its log line.

cd samples/python-fastapi
pip install -r requirements.txt && opentelemetry-bootstrap -a install
OTEL_SERVICE_NAME=orders-python WIZELENS_CAPTURE_BODY=true opentelemetry-instrument uvicorn app:app --port 5302