aws-embedded-metrics-golang

Go implementation of AWS CloudWatch Embedded Metric Format

It's aim is to simplify reporting metrics to CloudWatch:

• using EMF avoids additional HTTP API calls to CloudWatch as metrics are logged in JSON format to stdout
• no need for additional dependencies in your services (or mocks in tests) to report metrics from inside your code
• built in support for default dimensions and properties for Lambda functions

Supports namespaces, setting dimensions and properties as well as different contexts (at least partially).

Installation

go get github.com/prozz/aws-embedded-metrics-golang

Usage

emf.New().Namespace("mtg").Metric("totalWins", 1500).Log()

emf.New().Dimension("colour", "red").
    MetricAs("gameLength", 2, emf.Seconds).Log()

emf.New().DimensionSet(
        emf.NewDimension("format", "edh"),
        emf.NewDimension("commander", "Muldrotha")).
    MetricAs("wins", 1499, emf.Count).Log()

You may also use the lib together with defer.

m := emf.New() // sets up whatever you fancy here
defer m.Log()

// any reporting metrics calls

Customizing the logger:

emf.New(
    emf.WithWriter(os.Stderr), // Log to stderr.
    emf.WithTimestamp(time.Now().Add(-time.Hour)), // Record past metrics.
    emf.WithoutDimensions(), // Do not include useful Lambda related dimensions.
    emf.WithLogGroup("my-logs") // Add specific log group.
)

Functions for reporting metrics:

func Metric(name string, value int)
func Metrics(m map[string]int)
func MetricAs(name string, value int, unit MetricUnit)
func MetricsAs(m map[string]int, unit MetricUnit)

func MetricFloat(name string, value float64)
func MetricsFloat(m map[string]float64)
func MetricFloatAs(name string, value float64, unit MetricUnit)
func MetricsFloatAs(m map[string]float64, unit MetricUnit)

Functions for setting up dimensions:

func Dimension(key, value string)
func DimensionSet(dimensions ...Dimension) // use `func NewDimension` for creating one

Contributing

Pull requests are welcome. For major changes, please open an issue first to discuss what you would like to change. Please make sure to update tests.

License

MIT