signalfx-lambda 0.1.2

SignalFx Lambda Python Wrapper

SignalFx Python Lambda Wrapper.

Usage

The SignalFx Python Lambda Wrapper is a wrapper around an AWS Lambda Python function handler, used to instrument execution of the function and send metrics and traces to SignalFx.

Installation

To install from PyPi

$ pip install signalfx_lambda

Configuring the ingest endpoint

By default, this function wrapper will send to the us0 realm. If you are not in this realm you will need to set the SIGNALFX_INGEST_ENDPOINT environment variable to the correct realm ingest endpoint (https://ingest.{REALM}.signalfx.com). To determine what realm you are in, check your profile page in the SignalFx web application (click the avatar in the upper right and click My Profile).

Environment Variables

Note: the environment variables SIGNALFX_INGEST_ENDPOINT and SIGNALFX_AUTH_TOKEN are being deprecated and will not be supported in future releases.

SIGNALFX_ACCESS_TOKEN=access token

# endpoint for both metrics and tracer. Overridden by SIGNALFX_METRICS_URL
# and SIGNALFX_TRACING_URL if set
SIGNALFX_ENDPOINT_URL=endpoint url

# optional metrics and tracing configuration

SIGNALFX_METRICS_URL=ingest endpoint [ default: https://pops.signalfx.com ]
SIGNALFX_SEND_TIMEOUT=timeout in seconds for sending datapoint [ default: 0.3 ]

SIGNALFX_TRACING_URL=tracing endpoint [ default: https://ingest.signalfx.com/v1/trace ]

SIGNALFX_ENDPOINT_URL can be used to configure a common endpoint for metrics and traces, as is the case when forwarding with the Smart Gateway. The path /v1/traces will automatically be added to the endpoint for traces.

If either SIGNALFX_TRACING_URL or SIGNALFX_METRICS_URL are set, they will take precendence over SIGNALFX_ENDPOINT_URL for their respective components.

For example, if only SIGNALFX_ENDPOINT_URL is set:

SIGNALFX_ENDPOINT_URL=<gateway_address>

both metrics and traces will be sent to the gateway address.

If SIGNALFX_ENDPOINT_URL and SIGNALFX_METRICS_URL are set:

SIGNALFX_METRICS_URL=https://pops.signalfx.com

SIGNALFX_ENDPOINT_URL=<gateway_address>

Traces will be sent to the gateway and metrics will go through POPS.

Wrapping a function

There are two wrappers provided.

For metrics, decorate your handler with @signalfx_lambda.emits_metrics

import signalfx_lambda

@signalfx_lambda.emits_metrics
def handler(event, context):
    # your code

For tracing, use the @signalfx_lambda.is_traced decorator

import signalfx_lambda

@signalfx_lambda.is_traced
def handler(event, context):
    # your code

The decorators can be used individually or together.

Metrics and dimensions sent by the metrics wrapper

The Lambda wrapper sends the following metrics to SignalFx:

Metric Name	Type	Description
function.invocations	Counter	Count number of Lambda invocations
function.cold_starts	Counter	Count number of cold starts
function.errors	Counter	Count number of errors from underlying Lambda handler
function.duration	Gauge	Milliseconds in execution time of underlying Lambda handler

The Lambda wrapper adds the following dimensions to all data points sent to SignalFx:

Dimension	Description
aws_request_id	AWS Request ID
lambda_arn	ARN of the Lambda function instance
aws_region	AWS Region
aws_account_id	AWS Account ID
aws_function_name	AWS Function Name
aws_function_version	AWS Function Version
aws_function_qualifier	AWS Function Version Qualifier (version or version alias if it is not an event source mapping Lambda invocation)
event_source_mappings	AWS Function Name (if it is an event source mapping Lambda invocation)
aws_execution_env	AWS execution environment (e.g. AWS_Lambda_python3.6)
function_wrapper_version	SignalFx function wrapper qualifier (e.g. signalfx_lambda_0.0.2)
metric_source	The literal value of ‘lambda_wrapper’

Traces and tags sent by the Tracing wrapper

The tracing wrapper creates a span for the wrapper handler. This span has the following tags:

Tag	Description
aws_request_id	AWS Request ID
lambda_arn	ARN of the Lambda function instance
aws_region	AWS Region
aws_account_id	AWS Account ID
aws_function_name	AWS Function Name
aws_function_version	AWS Function Version
aws_function_qualifier	AWS Function Version Qualifier (version or version alias if it is not an event source mapping Lambda invocation)
event_source_mappings	AWS Function Name (if it is an event source mapping Lambda invocation)
aws_execution_env	AWS execution environment (e.g. AWS_Lambda_python3.6)
function_wrapper_version	SignalFx function wrapper qualifier (e.g. signalfx_lambda_0.0.2)
component	The literal value of ‘python-lambda-wrapper’

Sending custom metric from the Lambda function

import signalfx_lambda

# sending application_performance metric with value 100 and dimension abc:def
signalfx_lambda.send_gauge('application_performance', 100, {'abc':'def'})

# sending counter metric with no dimension
signalfx_lambda.send_counter('database_calls', 1)

Adding manual tracing to the Lambda function

Manual instrumentation can be added to trace critical parts of your handler function.

import opentracing

tracer = opentracing.tracer

def some_function():
    with tracer.start_active_span("span_name", tags=tags) as scope:

        # do some work

        span = scope.span
        span.set_tag("example_tag", "example_value")

More examples and usage information can be found in the Jaeger Python Tracer documentation.

Testing it out locally

Use python-lambda-local

pip install python-lambda-local

python-lambda-local tests/test.py tests/event.json -a 'arn:aws:lambda:us-east-1:accountId:function:functionNamePython:$LATEST'

Packaging

python setup.py bdist_wheel --universal

License

Apache Software License v2. Copyright © 2014-2019 SignalFx