Laravel Metrics

This package makes it incredibly easy to ship app metrics to backends such as PostHog, InfluxDB or CloudWatch.

There are two major components: a facade that lets you create metrics on your own, and an event listener to automatically send metrics for Laravel events.

Installation

You know the drill...

composer require stechstudio/laravel-metrics

Backend configuration

PostHog

1. Install the PostHog PHP client: composer require posthog/posthog-php

2. Add the following to your .env file:

METRICS_BACKEND=posthog
POSTHOG_API_KEY=...

InfluxDB v1.7 and under

1. Install the InfluxDB PHP client: composer require influxdb/influxdb-php

2. Add the following to your .env file:

METRICS_BACKEND=influxdb
IDB_USERNAME=...
IDB_PASSWORD=...
IDB_HOST=...
IDB_DATABASE=...
IDB_VERSION=1 # Default

# Only if you are not using the default 8086
IDB_TCP_PORT=...

# If you want to send metrics over UDP instead of TCP
IDB_UDP_PORT=...

InfluxDB V1.8 and above

1. Install the InfluxDB PHP client: composer require influxdata/influxdb-client-php

2. Add the following to your .env file:

3. In order to use UDP with InfluxDB V1.8+ you must follow extra setup steps

Add the following to your .env file:

METRICS_BACKEND=influxdb
IDB_TOKEN=...
IDB_DATABASE=... # Use the name of your desired bucket for this value
IDB_HOST=...
IDB_ORG=...
IDB_VERSION=2

# Only if you are not using the default 8086
IDB_TCP_PORT=...

# If you want to send metrics over UDP instead of TCP
IDB_UDP_PORT=...

CloudWatch

1. Install the AWS PHP SDK: composer require aws/aws-sdk-php.

2. Add the following to your .env file:

METRICS_BACKEND=cloudwatch
CLOUDWATCH_NAMESPACE=...

AWS_DEFAULT_REGION=...
AWS_ACCESS_KEY_ID=...
AWS_SECRET_ACCESS_KEY=...

Prometheus

1. Install the Prometheus PHP client: composer require promphp/prometheus_client_php
2. Configuring the backend to use Prometheus, makes sense only if you have an endpoint to expose them. Its purpose is only to format the registered metrics in a way that Prometheus can scrape them.

METRICS_BACKEND=prometheus

NullDriver (for development)

If you need to disable metrics just set the backend to null:

METRICS_BACKEND=null

This null driver will simply discard any metrics.

Sending an individual metric

You can create metric by using the facade like this:

Metrics::create('order_placed')
    ->setValue(1)
    ->setTags([
        'source' => 'email-campaign',
        'user' => 54
    ]);

The only required attribute is the name, everything else is optional.

Driver mapping

This is how we are mapping metric attributes in our backends.

Metric attribute	PostHog	InfluxDB	CloudWatch	Prometheus
name	event	measurement	MetricName	name
value	properties[value]	fields[value]	Value	value
unit	ignored	ignored	Unit	ignored
resolution	ignored	ignored	StorageResolution	ignored
tags	ignored	tags	Dimensions	keys -> labelNames values -> labelValues
extra	properties	fields	ignored	ignored
timestamp	ignored	timestamp	Timestamp	ignored
description	ignored	ignored	ignored	help
namespace	ignored	ignored	ignored	namespace
type	ignored	ignored	ignored	used to register counter or gauge metric

See the CloudWatch docs and InfluxDB docs for more information on their respective data formats. Note we only do minimal validation, you are expected to know what data types and formats your backend supports for a given metric attribute.

Sending metrics from Laravel events

The main motivation for this library was to send metrics automatically when certain events occur in a Laravel application. So this is where things really get fun!

Let's say you have a simple Laravel event called OrderReceived:

class OrderReceived {
    protected $order;
    
    public function __construct($order)
    {
        $this->order = $order;
    }
}

The first step is to implement an interface:

use STS\Metrics\Contracts\ShouldReportMetric;

class OrderReceived implements ShouldReportMetric {

This will tell the global event listener to send a metric for this event.

There are two different ways you can then provide the metric details.

1. Use the ProvidesMetric trait

You can also include a trait that helps with building this metric:

use STS\Metrics\Contracts\ShouldReportMetric;
use STS\Metrics\Traits\ProvidesMetric;

class OrderReceived implements ShouldReportMetric {
    use ProvidesMetric;

In this case, the trait will build a metric called order_received (taken from the class name) with a value of 1.

Customizing event metric data

If you decide to use the trait, you likely will want to customize the event metric data.

You can provide metric data with class attributes:

class OrderReceived implements ShouldReportMetric {
    use ProvidesMetric;
    
    protected $metricName = "new_order";
    protected $metricTags = ["category" => "revenue"];
    ...

Or if some of your metric data is dynamic you can use getter methods:

public function getMetricValue()
{
    return $this->order->total;
}

You can provide any of our metric attributes using these class attributes or getter methods.

2. Create the metric yourself

Depending on how much detail you need to provide for your metric, it may be simpler to just build it yourself. In this case you can ditch the trait and simply provide a public createMetric function that returns a new Metric instance:

use STS\Metrics\Contracts\ShouldReportMetric;
use STS\Metrics\Metric;

class OrderReceived implements ShouldReportMetric {
    protected $order;
    
    public function __construct($order)
    {
        $this->order = $order;
    }
    
    public function createMetric()
    {
        return (new Metric('order_received'))
            ->setValue(...)
            ->setTags([...])
            ->setTimestamp(...)
            ->setResolutions(...);
    }
}