kube-dns Integration
Overview
Get metrics from kube-dns service in real time to:
- Visualize and monitor DNS metrics collected with the Kubernetes’ kube-dns addon through Prometheus
See https://github.com/kubernetes/kubernetes/tree/master/cluster/addons/dns for more information about kube-dns.
Setup
Installation
The kube-dns check is included in the Datadog Agent package, so you don’t need to install anything else on your servers.
Configuration
Edit the kube_dns.d/conf.yaml file, in the conf.d/ folder at the root of your Agent’s configuration directory. See the sample kube_dns.d/conf.yaml for all available configuration options.
Using with service discovery
If you are using one Agent pod per Kubernetes worker node, use the following annotations on your kube-dns pod to retrieve the data automatically.
apiVersion: v1
kind: Pod
metadata:
annotations:
service-discovery.datadoghq.com/kubedns.check_names: '["kube_dns"]'
service-discovery.datadoghq.com/kubedns.init_configs: '[{}]'
service-discovery.datadoghq.com/kubedns.instances: '[[{"prometheus_endpoint":"http://%%host%%:10055/metrics", "tags":["dns-pod:%%host%%"]}]]'
Remarks:
- The “dns-pod” tag tracks the target DNS pod IP. The other tags are related to the dd-agent that is polling the information using the service discovery.
- The service discovery annotations need to be done on the pod. In case of a deployment, add the annotations to the metadata of the template’s spec.
Validation
Run the Agent’s status subcommand and look for kube_dns under the Checks section.
Data Collected
Metrics
| |
|---|
kubedns.cachemiss_count
(gauge) | Number of DNS requests resulting in a cache miss.
Shown as request |
kubedns.cachemiss_count.count
(count) | Instant number of DNS requests made resulting in a cache miss.
Shown as request |
kubedns.error_count
(gauge) | Number of DNS requests resulting in an error.
Shown as error |
kubedns.error_count.count
(count) | Instant number of DNS requests made resulting in an error.
Shown as error |
kubedns.request_count
(gauge) | Total number of DNS requests made.
Shown as request |
kubedns.request_count.count
(count) | Instant number of DNS requests made.
Shown as request |
kubedns.request_duration.seconds.count
(gauge) | Number of requests on which the kubedns.request_duration.seconds.sum metric is evaluated.
Shown as request |
kubedns.request_duration.seconds.sum
(gauge) | Time (in seconds) each request took to resolve.
Shown as second |
kubedns.response_size.bytes.count
(gauge) | Number of responses on which the kubedns.response_size.bytes.sum metric is evaluated.
Shown as response |
kubedns.response_size.bytes.sum
(gauge) | Size of the returns response in bytes.
Shown as byte |
Events
The kube-dns check does not include any events.
Service Checks
kubedns.up
Returns CRITICAL if Kube DNS is not healthy.
Statuses: ok, critical
Troubleshooting
Need help? Contact Datadog support.
