Flask-Observability

Make your Flask app observable using OpenTelemetry, logging and more.

• Auto instrument your app with OpenTelemetry
• Export spans and metrics via OTLP automatically
• Export logs in files or via Syslog and OTLP
• Utilities to use signals as counters and span events

Installation

pip install flask-observability

Usage

from flask import app
from flask_observability import Observability

app = Flask(__name__)
obs = Observability(app)

Important

Activate this extension before any other extensions

Important

No need to use the opentelemetry-instrument binary. (But if you do use it, instrumentation will not be performed by the extension)

Note

The OTLP endpoint defaults to "localhost" so it's easy to use OpenTelemetry Collector locally and forward to remote services from the collector

Warning

If app.debug is False, the OTLP exporter is enabled by default

Metrics

Easily get a metric object:

obs.counter("my-counter").add(1)
obs.gauge("my-gauge")
obs.histogram("my-histo")

Use a signal as a counter:

from blinker import signal

account_created = signal("account-created")
obs.signal_as_counter(account_created)

account_created.send()

Configuration

Logging

Config key	Description	Default
LOG_LEVEL	Level for the root logger	DEBUG if app.debug else INFO
LOG_FILENAME	Write logs from all loggers in a file
SYSLOG	Whether to enable Syslog	True if SYSLOG_HOST is set manually and not in debug mode, False otherwise
SYSLOG_HOST		localhost
SYSLOG_PORT		514
SYSLOG_FACILITY		local0
OTLP_LOG	Whether to enable sending logs via OTLP	False

Instrumentation

Config key	Description	Default
OTEL_INSTRUMENT	Whether to instrument the Flask app	True unless using opentelemetry-instrument
OTEL_AUTO_INSTRUMENT	Whether to auto initialize installed instrumentors (if OTEL_INSTRUMENT is true)	True
OTEL_DISABLE_AUTO_INSTRUMENTATIONS	Auto instrumentors to disable	[]
OTEL_INSTRUMENTORS	Import names or instrumentor classes to initialize	[]
OTLP_EXPORT	Whether to export span and metric using OTLP	OTEL_INSTRUMENT and not app.debug

OTLP exporters

Config key	Description	Default
OTLP_ENDPOINT		localhost:4317
OTLP_EXPORTER_OPTIONS	Keywords args that will be applied to ALL OTLP exporters used	{}
OTLP_SPAN_ENDPOINT	Specific endpoint for the span exporter	OTLP_ENDPOINT
OTLP_SPAN_EXPORTER_OPTIONS	Keyword args for the span exporter	{}
OTLP_METRIC_ENDPOINT	Specific endpoint for the metric exporter	OTLP_ENDPOINT
OTLP_METRIC_EXPORTER_OPTIONS	Keyword args for the metric exporter	{}
OTLP_LOG_ENDPOINT	Specific endpoint for the log exporter	OTLP_ENDPOINT
OTLP_LOG_EXPORTER_OPTIONS	Keyword args for the log exporter	{}

Misc

Config key	Description	Default
OTEL_SERVICE_NAME	Name of the service to use in the resource definition	app.import_name
OTEL_RESOURCE_ATTRIBUTES	A dict of attributes for the resource (may override service name)	{}
OTEL_TRACER_NAME	Name of the default tracer	app.import_name
OTEL_METER_NAME	Name of the default meter	app.import_name