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CoreDNS

CoreDNS

Plugin: go.d.plugin Module: coredns

Overview

This collector monitors CoreDNS instances.

This collector is supported on all platforms.

This collector supports collecting metrics from multiple instances of this integration, including remote instances.

Default Behavior

Auto-Detection

This integration doesn’t support auto-detection.

Limits

The default configuration for this integration does not impose any limits on data collection.

Performance Impact

The default configuration for this integration is not expected to impose a significant performance impact on the system.

Setup

You can configure the coredns collector in two ways:

Method Best for How to
UI Fast setup without editing files Go to Nodes → Configure this node → Collectors → Jobs, search for coredns, then click + to add a job.
File If you prefer configuring via file, or need to automate deployments (e.g., with Ansible) Edit go.d/coredns.conf and add a job.

:::important

UI configuration requires paid Netdata Cloud plan.

:::

Prerequisites

No action required.

Configuration

Options

The following options can be defined globally: update_every, autodetection_retry.

Group Option Description Default Required
Collection update_every Data collection interval (seconds). 1 no
autodetection_retry Autodetection retry interval (seconds). Set 0 to disable. 0 no
Target url Target endpoint URL. http://127.0.0.1:9153/metrics yes
timeout HTTP request timeout (seconds). 1 no
Filters per_server_stats Server filter. no
per_zone_stats Zone filter. no
HTTP Auth username Username for Basic HTTP authentication. no
password Password for Basic HTTP authentication. no
bearer_token_file Path to a file containing a bearer token (used for Authorization: Bearer). no
TLS tls_skip_verify Skip TLS certificate and hostname verification (insecure). no no
tls_ca Path to CA bundle used to validate the server certificate. no
tls_cert Path to client TLS certificate (for mTLS). no
tls_key Path to client TLS private key (for mTLS). no
Proxy proxy_url HTTP proxy URL. no
proxy_username Username for proxy Basic HTTP authentication. no
proxy_password Password for proxy Basic HTTP authentication. no
Request method HTTP method to use. GET no
body Request body (e.g., for POST/PUT). no
headers Additional HTTP headers (one per line as key: value). no
not_follow_redirects Do not follow HTTP redirects. no no
force_http2 Force HTTP/2 (including h2c over TCP). no no
Virtual Node vnode Associates this data collection job with a Virtual Node. no
per_server_stats

Metrics of servers matching the selector will be collected.

  • Logic: (pattern1 OR pattern2) AND !(pattern3 or pattern4)
  • Pattern syntax: matcher.
  • Syntax:
per_server_stats:
  includes:
    - pattern1
    - pattern2
  excludes:
    - pattern3
    - pattern4
per_zone_stats

Metrics of zones matching the selector will be collected.

  • Logic: (pattern1 OR pattern2) AND !(pattern3 or pattern4)
  • Pattern syntax: matcher.
  • Syntax:
per_zone_stats:
  includes:
    - pattern1
    - pattern2
  excludes:
    - pattern3
    - pattern4

via UI

Configure the coredns collector from the Netdata web interface:

  1. Go to Nodes.
  2. Select the node where you want the coredns data-collection job to run and click the :gear: (Configure this node). That node will run the data collection.
  3. The Collectors → Jobs view opens by default.
  4. In the Search box, type coredns (or scroll the list) to locate the coredns collector.
  5. Click the + next to the coredns collector to add a new job.
  6. Fill in the job fields, then click Test to verify the configuration and Submit to save.
    • Test runs the job with the provided settings and shows whether data can be collected.
    • If it fails, an error message appears with details (for example, connection refused, timeout, or command execution errors), so you can adjust and retest.

via File

The configuration file name for this integration is go.d/coredns.conf.

The file format is YAML. Generally, the structure is:

update_every: 1
autodetection_retry: 0
jobs:
  - name: some_name1
  - name: some_name2

You can edit the configuration file using the edit-config script from the Netdata config directory.

cd /etc/netdata 2>/dev/null || cd /opt/netdata/etc/netdata
sudo ./edit-config go.d/coredns.conf
Examples
Basic

An example configuration.

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics
Basic HTTP auth

Local server with basic HTTP authentication.

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics
    username: foo
    password: bar
Multi-instance

Note: When you define multiple jobs, their names must be unique.

Collecting metrics from local and remote instances.

jobs:
  - name: local
    url: http://127.0.0.1:9153/metrics

  - name: remote
    url: http://203.0.113.10:9153/metrics

Metrics

Metrics grouped by scope.

The scope defines the instance that the metric belongs to. An instance is uniquely identified by a set of labels.

Per CoreDNS instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric Dimensions Unit
coredns.dns_request_count_total requests requests/s
coredns.dns_responses_count_total responses responses/s
coredns.dns_request_count_total_per_status processed, dropped requests/s
coredns.dns_no_matching_zone_dropped_total dropped requests/s
coredns.dns_panic_count_total panics panics/s
coredns.dns_requests_count_total_per_proto udp, tcp requests/s
coredns.dns_requests_count_total_per_ip_family v4, v6 requests/s
coredns.dns_requests_count_total_per_per_type a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other requests/s
coredns.dns_responses_count_total_per_rcode noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other responses/s

Per server

These metrics refer to the DNS server.

Labels:

Label Description
server_name Server name.

Metrics:

Metric Dimensions Unit
coredns.server_dns_request_count_total requests requests/s
coredns.server_dns_responses_count_total responses responses/s
coredns.server_request_count_total_per_status processed, dropped requests/s
coredns.server_requests_count_total_per_proto udp, tcp requests/s
coredns.server_requests_count_total_per_ip_family v4, v6 requests/s
coredns.server_requests_count_total_per_per_type a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other requests/s
coredns.server_responses_count_total_per_rcode noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other responses/s

Per zone

These metrics refer to the DNS zone.

Labels:

Label Description
zone_name Zone name.

Metrics:

Metric Dimensions Unit
coredns.zone_dns_request_count_total requests requests/s
coredns.zone_dns_responses_count_total responses responses/s
coredns.zone_requests_count_total_per_proto udp, tcp requests/s
coredns.zone_requests_count_total_per_ip_family v4, v6 requests/s
coredns.zone_requests_count_total_per_per_type a, aaaa, mx, soa, cname, ptr, txt, ns, ds, dnskey, rrsig, nsec, nsec3, ixfr, any, other requests/s
coredns.zone_responses_count_total_per_rcode noerror, formerr, servfail, nxdomain, notimp, refused, yxdomain, yxrrset, nxrrset, notauth, notzone, badsig, badkey, badtime, badmode, badname, badalg, badtrunc, badcookie, other responses/s

Alerts

There are no alerts configured by default for this integration.

Troubleshooting

Debug Mode

Important: Debug mode is not supported for data collection jobs created via the UI using the Dyncfg feature.

To troubleshoot issues with the coredns collector, run the go.d.plugin with the debug option enabled. The output should give you clues as to why the collector isn’t working.

  • Navigate to the plugins.d directory, usually at /usr/libexec/netdata/plugins.d/. If that’s not the case on your system, open netdata.conf and look for the plugins setting under [directories].

    cd /usr/libexec/netdata/plugins.d/

  • Switch to the netdata user.

    sudo -u netdata -s

  • Run the go.d.plugin to debug the collector:

    ./go.d.plugin -d -m coredns

    To debug a specific job:

    ./go.d.plugin -d -m coredns -j jobName

Getting Logs

If you’re encountering problems with the coredns collector, follow these steps to retrieve logs and identify potential issues:

  • Run the command specific to your system (systemd, non-systemd, or Docker container).
  • Examine the output for any warnings or error messages that might indicate issues. These messages should provide clues about the root cause of the problem.

System with systemd

Use the following command to view logs generated since the last Netdata service restart:

journalctl _SYSTEMD_INVOCATION_ID="$(systemctl show --value --property=InvocationID netdata)" --namespace=netdata --grep coredns

System without systemd

Locate the collector log file, typically at /var/log/netdata/collector.log, and use grep to filter for collector’s name:

grep coredns /var/log/netdata/collector.log

Note: This method shows logs from all restarts. Focus on the latest entries for troubleshooting current issues.

Docker Container

If your Netdata runs in a Docker container named “netdata” (replace if different), use this command:

docker logs netdata 2>&1 | grep coredns

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