Kubelet

Plugin: go.d.plugin Module: k8s_kubelet

Overview

This collector monitors Kubelet 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.

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 Kubelet instance

These metrics refer to the entire monitored application.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
k8s_kubelet.apiserver_audit_requests_rejected	rejected	requests/s
k8s_kubelet.apiserver_storage_data_key_generation_failures	failures	events/s
k8s_kubelet.apiserver_storage_data_key_generation_latencies	5_µs, 10_µs, 20_µs, 40_µs, 80_µs, 160_µs, 320_µs, 640_µs, 1280_µs, 2560_µs, 5120_µs, 10240_µs, 20480_µs, 40960_µs, +Inf	observes/s
k8s_kubelet.apiserver_storage_data_key_generation_latencies_percent	5_µs, 10_µs, 20_µs, 40_µs, 80_µs, 160_µs, 320_µs, 640_µs, 1280_µs, 2560_µs, 5120_µs, 10240_µs, 20480_µs, 40960_µs, +Inf	percentage
k8s_kubelet.apiserver_storage_envelope_transformation_cache_misses	cache misses	events/s
k8s_kubelet.kubelet_containers_running	total	running_containers
k8s_kubelet.kubelet_pods_running	total	running_pods
k8s_kubelet.kubelet_pods_log_filesystem_used_bytes	a dimension per namespace and pod	B
k8s_kubelet.kubelet_runtime_operations	a dimension per operation type	operations/s
k8s_kubelet.kubelet_runtime_operations_errors	a dimension per operation type	errors/s
k8s_kubelet.kubelet_docker_operations	a dimension per operation type	operations/s
k8s_kubelet.kubelet_docker_operations_errors	a dimension per operation type	errors/s
k8s_kubelet.kubelet_node_config_error	experiencing_error	bool
k8s_kubelet.kubelet_pleg_relist_interval_microseconds	0.5, 0.9, 0.99	microseconds
k8s_kubelet.kubelet_pleg_relist_latency_microseconds	0.5, 0.9, 0.99	microseconds
k8s_kubelet.kubelet_token_requests	total, failed	token_requests/s
k8s_kubelet.rest_client_requests_by_code	a dimension per HTTP status code	requests/s
k8s_kubelet.rest_client_requests_by_method	a dimension per HTTP method	requests/s

Per volume manager

These metrics refer to the Volume Manager.

This scope has no labels.

Metrics:

Metric	Dimensions	Unit
k8s_kubelet.volume_manager_total_volumes	actual, desired	state

Alerts

The following alerts are available:

Alert name	On metric	Description
kubelet_node_config_error	k8s_kubelet.kubelet_node_config_error	the node is experiencing a configuration-related error (0: false, 1: true)
kubelet_token_requests	k8s_kubelet.kubelet_token_requests	number of failed Token() requests to the alternate token source
kubelet_token_requests	k8s_kubelet.kubelet_token_requests	number of failed Token() requests to the alternate token source
kubelet_operations_error	k8s_kubelet.kubelet_operations_errors	number of Docker or runtime operation errors
kubelet_operations_error	k8s_kubelet.kubelet_operations_errors	number of Docker or runtime operation errors

Setup

Prerequisites

No action required.

Configuration

File

The configuration file name for this integration is go.d/k8s_kubelet.conf.

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

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

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/k8s_kubelet.conf

Options

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

Config options

Name	Description	Default	Required
update_every	Data collection frequency.	1	no
autodetection_retry	Recheck interval in seconds. Zero means no recheck will be scheduled.	0	no
url	Server URL.	http://127.0.0.1:10255/metrics	yes
timeout	HTTP request timeout.	1	no
username	Username for basic HTTP authentication.		no
password	Password for basic HTTP authentication.		no
proxy_url	Proxy URL.		no
proxy_username	Username for proxy basic HTTP authentication.		no
proxy_password	Password for proxy basic HTTP authentication.		no
method	HTTP request method.	GET	no
body	HTTP request body.		no
headers	HTTP request headers.		no
not_follow_redirects	Redirect handling policy. Controls whether the client follows redirects.	no	no
tls_skip_verify	Server certificate chain and hostname validation policy. Controls whether the client performs this check.	no	no
tls_ca	Certification authority that the client uses when verifying the server's certificates.		no
tls_cert	Client TLS certificate.		no
tls_key	Client TLS key.		no

Examples

Basic

A basic example configuration.

jobs:
  - name: local
    url: http://127.0.0.1:10255/metrics

HTTPS with self-signed certificate

Do not validate server certificate chain and hostname.

Config

jobs:
  - name: local
    url: http://127.0.0.1:10250/metrics
    tls_skip_verify: yes

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 k8s_kubelet 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 k8s_kubelet

Getting Logs

If you're encountering problems with the k8s_kubelet 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 k8s_kubelet

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 k8s_kubelet /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 k8s_kubelet