@middy/cloudwatch-metrics

Middy Cloudwatch metrics middleware

Metrics middleware for the middy framework, the stylish Node.js middleware engine for AWS Lambda

This middleware hydrates lambda's context.metrics property with an instance of MetricLogger. This instance can be used to easily generate custom metrics from Lambda functions without requiring custom batching code, making blocking network requests or relying on 3rd party software.

Metrics collected with this logger are then available for querying within AWS CloudWatch Log Insights

You can explore all the MetricLogger APIs following aws-embedded-metrics documentation.

Install

To install this middleware you can use NPM:

npm install --save @middy/metrics

Options

• namespace (string) (optional): Defaults to aws-embedded-metrics. Sets the CloudWatch namespace that extracted metrics should be published to.
• dimensions (Record<String, String>[]) (optional): Defaults to

  [
      {"ServiceName": "myLambdaFunctionName"},
      {"ServiceType": "AWS::Lambda::Function"},
      {"LogGroupName": "logGroupNameUsedByMyLambda"},
  ]
  

  Explicitly override all dimensions. This will remove the default dimensions. You can provide an empty array to record all metrics without dimensions.

Sample usage

const middy = require('@middy/core')
const metrics = require('@middy/metrics')

const handler = middy((event, context, cb) => {
    context.metrics.putMetric("ProcessingLatency", 100, "Milliseconds");
    context.metrics.setProperty("RequestId", "422b1569-16f6-4a03-b8f0-fe3fd9b100f8")
    cb(null, {})
})

handler.use(metrics({
    namspace: "myAppliction",
    dimensions: [
        { "Action": "Buy" }
    ]
}))

Middy documentation and examples

For more documentation and examples, refers to the main Middy monorepo on GitHub or Middy official website.

Contributing

Everyone is very welcome to contribute to this repository. Feel free to raise issues or to submit Pull Requests.

License

Licensed under MIT License. Copyright (c) 2017-2018 Luciano Mammino and the Middy team.