MFab::Plugin::Datadog

A comprehensive Mojolicious plugin that provides deep integration with Datadog's Application Performance Monitoring (APM) system. This plugin automatically instruments your Mojolicious applications to provide detailed performance insights and distributed tracing capabilities.

Key Features

• Automatic Request Tracing: Every HTTP request is automatically traced with detailed timing information
• Distributed Tracing: Seamlessly propagates trace context across service boundaries
• Custom Span Support: API for adding custom spans to track specific operations
• Real-time Metrics: Monitor application performance in real-time through Datadog's dashboard
• Zero-Configuration: Works out of the box with sensible defaults
• Production Ready: Battle-tested in production environments

Example webserver

See the example/ directory

Installation

cpanm --install .

Usage

To use the plugin in your Mojolicious application, add it to your startup method:

package MyApp;
use Mojo::Base qw(Mojolicious -signatures);

sub startup ($self) {
    # Add MFab::Plugins to the plugin namespace search
    push(@{ $self->plugins->namespaces }, 'MFab::Plugins');

    # Load the Datadog plugin
    $self->plugin('Datadog', { enabled => "true" });

    # Other startup code...
}

Configuration

The plugin accepts the following configuration options:

• datadogHost - the datadog agent host, also looks in the ENV for DD_AGENT_HOST, defaults to localhost
• enabled - should we send traces to datadog, also looks in the ENV for DD_TRACE_ENABLED, defaults to false
• serviceEnv - the value to send to datadog for the service environment, defaults to test

Features

• Metrics Collection: Automatically collect and send metrics to Datadog APM.
• Datadog APM Ecosystem: Automatically uses the Datadog headers to trace cross-app requests
• Custom Metrics: Define and send custom metrics from your application.

Custom Metrics

In Datadog, traces can contain multiple spans. Each span can have a parent to describe the relationship between them. In order to include your own spans in the trace, they need to be associated with the Mojolicious transaction. Below is an example:

package MyWebserverApp;
use MFab::Plugins::Datadog qw(startSpan endSpan);
use Mojo::Base qw(Mojolicious::Controller -signatures);

sub request ($c) {
    my $span = startSpan($c->tx, "MyWebserverApp::request", "/requesturl");
    # process request
    $c->render(text => "Done");
    endSpan($span);
}

By default, the parent is associated with the active Mojolicious hook spans. You can also pass in a span to startSpan to use as the parent if you have one

Contributing

1. Fork the repository.
2. Create a new branch (git checkout -b feature-branch).
3. Commit your changes (git commit -am 'Add new feature').
4. Push to the branch (git push origin feature-branch).
5. Create a new Pull Request.

Acknowledgments

• Mojolicious
• Datadog