Documentation Grafana Cloud Monitor infrastructure Grafana integrations Integrations reference CoreDNS

CoreDNS integration for Grafana Cloud

CoreDNS is a fast and efficient DNS server written in Go, that chains plugins, where each plugin performs a (DNS) function.

This integration includes 9 useful alerts and 1 pre-built dashboard to help monitor and visualize CoreDNS metrics.

Before you begin

This integration supports CoreDNS version 1.7.0 or greater.

To make metrics available on CoreDNS, both the Prometheus plugin and cache plugin must be enabled.

Install CoreDNS integration for Grafana Cloud

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

Configuration snippets for Grafana Alloy

Simple mode

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

First, manually copy and append the following snippets into your alloy configuration file.

Metrics snippets

alloy Copy

discovery.relabel "metrics_integrations_integrations_coredns" {
	targets = [{
		__address__ = "localhost:9153",
		cluster     = "cloud",
	}]

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

prometheus.scrape "metrics_integrations_integrations_coredns" {
	targets    = discovery.relabel.metrics_integrations_integrations_coredns.output
	forward_to = [prometheus.remote_write.metrics_service.receiver]
	job_name   = "integrations/coredns"
}

Advanced mode

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

To instruct Grafana Alloy to scrape your CoreDNS instances, manually copy and append the snippets to your alloy configuration file, then follow subsequent instructions.

Advanced metrics snippets

alloy Copy

discovery.relabel "metrics_integrations_integrations_coredns" {
	targets = [{
		__address__ = "localhost:9153",
		cluster     = "cloud",
	}]

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

prometheus.scrape "metrics_integrations_integrations_coredns" {
	targets    = discovery.relabel.metrics_integrations_integrations_coredns.output
	forward_to = [prometheus.remote_write.metrics_service.receiver]
	job_name   = "integrations/coredns"
}

To monitor your CoreDNS instance, you must use a discovery.relabel component to discover your CoreDNS 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 CoreDNS 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 CoreDNS instance.
• cluster: If you are running on k8s, set this to your k8s cluster name

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

Grafana Agent static configuration (deprecated)

The following section shows configuration for running Grafana Agent in static mode which is deprecated. You should use Grafana Alloy for all new deployments.

Instructions for Grafana Agent static

Dashboards

The CoreDNS integration installs the following dashboards in your Grafana Cloud instance to help monitor your system.

• CoreDNS

CoreDNS dashboard

Alerts

The CoreDNS integration includes the following useful alerts:

coredns

coredns_forward

Metrics

The most important metrics provided by the CoreDNS integration, which are used on the pre-built dashboard and Prometheus alerts, are as follows:

• coredns_build_info
• coredns_cache_entries
• coredns_cache_hits_total
• coredns_cache_misses_total
• coredns_dns_request_duration_seconds_bucket
• coredns_dns_request_size_bytes_bucket
• coredns_dns_requests_total
• coredns_dns_response_size_bytes_bucket
• coredns_dns_responses_total
• coredns_forward_healthcheck_broken_total
• coredns_forward_healthcheck_failures_total
• coredns_forward_request_duration_seconds_bucket
• coredns_forward_requests_total
• coredns_forward_responses_total
• coredns_panics_total
• coredns_plugin_enabled
• go_goroutines
• process_cpu_seconds_total
• process_resident_memory_bytes
• up

Changelog

md Copy

# 0.0.7 - September 2023

* New Filter Metrics option for configuring the Grafana Agent, which saves on metrics cost by dropping any metric not used by this integration. Beware that anything custom built using metrics that are not on the snippet will stop working.
* New hostname relabel option, which applies the instance name you write on the text box to the Grafana Agent configuration snippets, making it easier and less error prone to configure this mandatory label.

# 0.0.6 - August 2023

- Fix coredns alerts variable not found error

# 0.0.5 - July 2023

- Added Grafana Agent Operator configuration snippet to support CoreDNS in a kubernetes cluster
- Added cluster selector to dashboard for kubernetes support
- Added default cluster label to agent config

# 0.0.4 - April 2023

- Update alerts to include external labels

# 0.0.3 - January 2023

- Update to latest integration structure
- Update to latest upstream mixin

# 0.0.2 - October 2021

- Update mixin to latest version

# 0.0.1 - May 2021

- Initial release

Cost

By connecting your CoreDNS instance to Grafana Cloud, you might incur charges. To view information on the number of active series that your Grafana Cloud account uses for metrics included in each Cloud tier, see Active series and dpm usage and Cloud tier pricing.