CoreDNS

Use this Splunk Observability Cloud integration for the CoreDNS monitor. See benefits, install, configuration, and metrics

The Splunk Distribution of the OpenTelemetry Collector uses the Smart Agent receiver with the CoreDNS monitor type to scrape Prometheus metrics exposed by CoreDNS.

The default port for these metrics are exposed on port 9153, at the /metrics path.

Note: If you’re using the Splunk Distribution of the OpenTelemetry Collector and want to collect Prometheus metrics, see Monitor applications with Prometheus metrics.

Benefits

After you configure the integration, you can access these features:

View metrics. You can create your own custom dashboards, and most monitors provide built-in dashboards as well. For information about dashboards, see View dashboards in Splunk Observability Cloud.
View a data-driven visualization of the physical servers, virtual machines, AWS instances, and other resources in your environment that are visible to Infrastructure Monitoring. For information about navigators, see Use navigators in Splunk Infrastructure Monitoring.
Access the Metric Finder and search for metrics sent by the monitor. For information, see Search the Metric Finder and Metadata Catalog.

Installation

Follow these steps to deploy this integration:

Deploy the Splunk Distribution of the OpenTelemetry Collector to your host or container platform:
Configure the integration, as described in the Configuration section.
Restart the Splunk Distribution of the OpenTelemetry Collector.

Configuration

To use this integration of a Smart Agent monitor with the Collector:

Include the Smart Agent receiver in your configuration file.
Add the monitor type to the Collector configuration, both in the receiver and pipelines sections.
- See how to Use Smart Agent monitors with the Collector.
- See how to set up the Smart Agent receiver.
- For a list of common configuration options, refer to Common configuration settings for monitors.
- Learn more about the Collector at Get started: Understand and use the Collector.

Example

To activate this integration, add the following to your Collector configuration:

receivers:
  smartagent/coredns:
    type: coredns
    ...  # Additional config

Next, add the monitor to the service.pipelines.metrics.receivers section of your configuration file:

service:
  pipelines:
    metrics:
      receivers: [smartagent/coredns]

Configure a Kubernetes environment

Here is an example configuration for a Kubernetes environment:

receivers:
  smartagent/coredns:
    type: coredns
    discoveryRule: kubernetes_pod_name =~ "coredns" && port == 9153
    extraDimensions:
      metric_source: "k8s-coredns"

Configuration options

The following table shows the configuration options for this monitor:


Option	Required	Type	Description
`httpTimeout`	no	`int64`	HTTP timeout duration for both read and writes. Use a duration string that is accepted by https://golang.org/pkg/time/#ParseDuration (default: `10s`)
`username`	no	`string`	Basic Auth username to use on each request, if any.
`password`	no	`string`	Basic Auth password to use on each request, if any.
`useHTTPS`	no	`bool`	If true, the agent connects to the server using HTTPS instead of plain HTTP. (default: `false`)
`httpHeaders`	no	`map of strings`	A map of HTTP header names to values. Comma separated multiple values for the same message-header is supported.
`skipVerify`	no	`bool`	If `useHTTPS` is `true` and this option is also `true`, the exporter TLS cert is not verified. (default: `false`)
`caCertPath`	no	`string`	Path to the CA cert that has signed the TLS cert, unnecessary if `skipVerify` is set to false.
`clientCertPath`	no	`string`	Path to the client TLS cert to use for TLS required connections
`clientKeyPath`	no	`string`	Path to the client TLS key to use for TLS required connections
`host`	yes	`string`	Host of the exporter
`port`	yes	`integer`	Port of the exporter
`useServiceAccount`	no	`bool`	Use pod service account to authenticate. (default: `false`)
`metricPath`	no	`string`	Path to the metrics endpoint on the exporter server, usually `/metrics` (the default). (default: `/metrics`)
`sendAllMetrics`	no	`bool`	Send all the metrics that come out of the Prometheus exporter without any filtering. This option has no effect when using the Prometheus exporter monitor directly since there is no built-in filtering, only when embedding it in other monitors. (default: `false`)

Metrics

The following metrics are available for this integration:

https://raw.githubusercontent.com/signalfx/splunk-otel-collector/main/internal/signalfx-agent/pkg/monitors/coredns/metadata.yaml

Notes

To learn more about the available in Splunk Observability Cloud see Metric types.
In host-based subscription plans, default metrics are those metrics included in host-based subscriptions in Splunk Observability Cloud, such as host, container, or bundled metrics. Custom metrics are not provided by default and might be subject to charges. See Metric categories for more information.
In MTS-based subscription plans, all metrics are custom.
To add additional metrics, see how to configure extraMetrics in Add additional metrics.

Troubleshooting

If you are a Splunk Observability Cloud customer and are not able to see your data in Splunk Observability Cloud, you can get help in the following ways.

Available to Splunk Observability Cloud customers

Submit a case in the Splunk Support Portal.
Contact Splunk Support.

Available to prospective customers and free trial users

Ask a question and get answers through community support at Splunk Answers.
Join the Splunk #observability user group Slack channel to communicate with customers, partners, and Splunk employees worldwide. To join, see Chat groups.

Documentation