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Kubelet

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.

Setup

You can configure the k8s_kubelet 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 k8s_kubelet, 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/k8s_kubelet.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://127.0.0.1:10255/metrics yes
timeout HTTP request timeout (seconds). 1 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). /var/run/secrets/kubernetes.io/serviceaccount/token 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

via UI

Configure the k8s_kubelet collector from the Netdata web interface:

  1. Go to Nodes.
  2. Select the node where you want the k8s_kubelet 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 k8s_kubelet (or scroll the list) to locate the k8s_kubelet collector.
  5. Click the + next to the k8s_kubelet 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/k8s_kubelet.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/k8s_kubelet.conf
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.

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

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

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

    To debug a specific job:

    ./go.d.plugin -d -m k8s_kubelet -j jobName

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

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