Ruby Rack integration for Grafana Cloud

Before you begin

This integration monitors a Rack web application (e.g. any Sinatra or Rails application) using the Collector middleware included in the Ruby Prometheus client library.

To get started, add the Prometheus client library to your Gemfile:

rb Copy

gem 'prometheus-client'

Then change the config.ru file of your Rack application to use the Prometheus Collector and Exporter middlewares before running your app:

rb Copy

require 'prometheus/middleware/collector'
require 'prometheus/middleware/exporter'

use Prometheus::Middleware::Collector
use Prometheus::Middleware::Exporter

run Sinatra::Application

You can refer to this example Sinatra app for a complete setup of the Prometheus client library.

Install Ruby Rack integration for Grafana Cloud

1. In your Grafana Cloud stack, click Connections in the left-hand menu.
2. Find Ruby Rack and click its tile to open the integration.
3. Review the prerequisites in the Configuration Details tab and set up Grafana Agent to send Ruby Rack metrics to your Grafana Cloud instance.
4. Click Install to add this integration’s pre-built dashboard to your Grafana Cloud instance, and you can start monitoring your Ruby Rack setup.

Configuration snippets for Grafana Alloy

Simple mode

These snippets are configured to scrape a single Ruby Rack instance running locally with default ports.

Copy and paste the following snippets into your Grafana Alloy configuration file.

Metrics snippets

river Copy

discovery.relabel "metrics_integrations_integrations_ruby_rack" {
	targets = [{
		__address__ = "localhost:9292",
	}]

	rule {
		target_label = "instance"
		replacement  = constants.hostname
	}
}

prometheus.scrape "metrics_integrations_integrations_ruby_rack" {
	targets    = discovery.relabel.metrics_integrations_integrations_ruby_rack.output
	forward_to = [prometheus.remote_write.metrics_service.receiver]
	job_name   = "integrations/ruby-rack"
}

Advanced mode

The following snippets provide examples to guide you through the configuration process.

To instruct Grafana Alloy to scrape your Ruby Rack instances, copy and paste the snippets to your configuration file and follow subsequent instructions.

Advanced metrics snippets

river Copy

discovery.relabel "metrics_integrations_integrations_ruby_rack" {
	targets = [{
		__address__ = "localhost:9292",
	}]

	rule {
		target_label = "instance"
		replacement  = constants.hostname
	}
}

prometheus.scrape "metrics_integrations_integrations_ruby_rack" {
	targets    = discovery.relabel.metrics_integrations_integrations_ruby_rack.output
	forward_to = [prometheus.remote_write.metrics_service.receiver]
	job_name   = "integrations/ruby-rack"
}

To monitor your Ruby Rack instance, you must use a discovery.relabel component to discover your Ruby Rack Prometheus endpoint and apply appropriate labels, followed by a prometheus.scrape component to scrape it.

Configure the following properties within each discovery.relabel component:

• __address__: The address to your Ruby Rack Prometheus metrics endpoint.
• instance label: constants.hostname sets the instance label to your Grafana Alloy server hostname. If that is not suitable, change it to a value uniquely identifies this Ruby Rack instance.

If you have multiple Ruby Rack servers to scrape, configure one discovery.relabel for each and scrape them by including each under targets within the prometheus.scrape component.

Before you begin

This integration monitors a Rack web application (e.g. any Sinatra or Rails application) using the Collector middleware included in the Ruby Prometheus client library.

To get started, add the Prometheus client library to your Gemfile:

rb Copy

gem 'prometheus-client'

Then change the config.ru file of your Rack application to use the Prometheus Collector and Exporter middlewares before running your app:

rb Copy

require 'prometheus/middleware/collector'
require 'prometheus/middleware/exporter'

use Prometheus::Middleware::Collector
use Prometheus::Middleware::Exporter

run Sinatra::Application

You can refer to this example Sinatra app for a complete setup of the Prometheus client library.

Install Ruby Rack integration for Grafana Cloud

1. In your Grafana Cloud stack, click Connections in the left-hand menu.
2. Find Ruby Rack and click its tile to open the integration.
3. Review the prerequisites in the Configuration Details tab and set up Grafana Agent to send Ruby Rack metrics to your Grafana Cloud instance.
4. Click Install to add this integration’s pre-built dashboard to your Grafana Cloud instance, and you can start monitoring your Ruby Rack setup.

Post-install configuration for the Ruby Rack integration

After enabling the metrics generation, you should instruct Grafana Agent to scrape your Ruby application.

The Ruby Prometheus client lib exposes a /metrics endpoint. To scrape it, add the provided snippet to your agent configuration file.

Make sure to change targets in the snippet according to your environment.

Configuration snippets for Grafana Agent

Below metrics.configs.scrape_configs, insert the following lines and change the URLs according to your environment:

yaml Copy

    - job_name: integrations/ruby-rack
      relabel_configs:
        - replacement: '<your-instance-name>'
          target_label: instance
      static_configs:
        - targets: ['localhost:9292']

Full example configuration for Grafana Agent

Refer to the following Grafana Agent configuration for a complete example that contains all the snippets used for the Ruby Rack integration. This example also includes metrics that are sent to monitor your Grafana Agent instance.

yaml Copy

integrations:
  prometheus_remote_write:
  - basic_auth:
      password: <your_prom_pass>
      username: <your_prom_user>
    url: <your_prom_url>
  agent:
    enabled: true
    relabel_configs:
    - action: replace
      source_labels:
      - agent_hostname
      target_label: instance
    - action: replace
      target_label: job
      replacement: "integrations/agent-check"
    metric_relabel_configs:
    - action: keep
      regex: (prometheus_target_sync_length_seconds_sum|prometheus_target_scrapes_.*|prometheus_target_interval.*|prometheus_sd_discovered_targets|agent_build.*|agent_wal_samples_appended_total|process_start_time_seconds)
      source_labels:
      - __name__
  # Add here any snippet that belongs to the `integrations` section.
  # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
logs:
  configs:
  - clients:
    - basic_auth:
        password: <your_loki_pass>
        username: <your_loki_user>
      url: <your_loki_url>
    name: integrations
    positions:
      filename: /tmp/positions.yaml
    scrape_configs:
      # Add here any snippet that belongs to the `logs.configs.scrape_configs` section.
      # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
metrics:
  configs:
  - name: integrations
    remote_write:
    - basic_auth:
        password: <your_prom_pass>
        username: <your_prom_user>
      url: <your_prom_url>
    scrape_configs:
      # Add here any snippet that belongs to the `metrics.configs.scrape_configs` section.
      # For a correct indentation, paste snippets copied from Grafana Cloud at the beginning of the line.
    - job_name: integrations/ruby-rack
      relabel_configs:
        - replacement: '<your-instance-name>'
          target_label: instance
      static_configs:
        - targets: ['localhost:9292']
  global:
    scrape_interval: 60s
  wal_directory: /tmp/grafana-agent-wal