Python FastAPI Uvicorn
Prerequisites
Python 3
Installation
-
Install dependencies:
pip install opentelemetry-distro opentelemetry-exporter-otlp-proto-http opentelemetry-instrumentation-fastapi opentelemetry-instrumentation-system-metrics
opentelemetry-bootstrap -a install -
Create a file
tracing.py
in your project directory, with the following content:tracing.pyimport os
from opentelemetry import trace
from opentelemetry.sdk import resources
from opentelemetry.sdk.trace import TracerProvider
from opentelemetry.sdk.trace.export import (
BatchSpanProcessor,
ConsoleSpanExporter,
SimpleSpanProcessor,
)
from opentelemetry.exporter.otlp.proto.http.trace_exporter import OTLPSpanExporter
from opentelemetry import metrics
from opentelemetry.sdk.metrics import MeterProvider
from opentelemetry.sdk.metrics.export import (
ConsoleMetricExporter,
PeriodicExportingMetricReader,
)
from opentelemetry.exporter.otlp.proto.http.metric_exporter import OTLPMetricExporter
from opentelemetry.instrumentation.system_metrics import SystemMetricsInstrumentor
from socket import gethostname
def init_tracing():
resource = resources.Resource.create({
resources.HOST_NAME: gethostname() or 'UNSET',
})
if os.getenv('OTEL_LOG_LEVEL', '') == 'debug':
trace_processor = SimpleSpanProcessor(ConsoleSpanExporter())
else:
trace_processor = BatchSpanProcessor(OTLPSpanExporter())
trace_provider = TracerProvider(
resource=resource,
active_span_processor=trace_processor
)
trace.set_tracer_provider(trace_provider)
if os.getenv('OTEL_LOG_LEVEL', '') == 'debug':
metric_exporter = ConsoleMetricExporter()
else:
metric_exporter = OTLPMetricExporter()
metric_reader = PeriodicExportingMetricReader(exporter=metric_exporter)
meter_provider = MeterProvider(
resource=resource,
metric_readers=[metric_reader]
)
metrics.set_meter_provider(meter_provider)
SystemMetricsInstrumentor().instrument() -
Add the highlighted lines below to your project's main file:
main.pyfrom fastapi import FastAPI
from tracing import init_tracing
from opentelemetry.instrumentation.fastapi import FastAPIInstrumentor
app = FastAPI()
init_tracing()
FastAPIInstrumentor.instrument_app(app)
# Additional instrumentations can be enabled by
# following the docs for respective instrumentations at
# https://github.com/open-telemetry/opentelemetry-python-contrib/tree/main/instrumentation
#
# A working example with multiple instrumentations is available at
# https://github.com/cubeapm/sample_app_python_fastapi_uvicorn/tree/otel
@app.route('/roll/<number>')
def roll(number):
return number -
Modify the application run command as follows:
OTEL_LOGS_EXPORTER=none \
OTEL_EXPORTER_OTLP_TRACES_ENDPOINT=http://<ip_address_of_cubeapm_server>:4318/v1/traces \
OTEL_EXPORTER_OTLP_METRICS_ENDPOINT=http://<ip_address_of_cubeapm_server>:3130/api/metrics/v1/save/otlp \
OTEL_EXPORTER_OTLP_COMPRESSION=gzip \
OTEL_SERVICE_NAME=<app_name> \
uvicorn main:app --host=0.0.0.0 --port=8000 --workers=4
Sample Application
A working example is available at https://github.com/cubeapm/sample_app_python_fastapi_uvicorn/tree/otel.
Troubleshooting
The following can be used for debugging:
OTEL_LOG_LEVEL=debug
The following command can be tried on the application host server to check connectivity to CubeAPM server(s):
telnet <ip_address_of_cubeapm_server> 4318