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Merge pull request #46064 from windsonsea/configy
Make a task prettier: kubelet-config-file
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‎content/en/docs/tasks/administer-cluster/kubelet-config-file.md

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@@ -38,6 +38,7 @@ The configuration file must be a JSON or YAML representation of the parameters
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in this struct. Make sure the kubelet has read permissions on the file.
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Here is an example of what this file might look like:
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```yaml
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apiVersion: kubelet.config.k8s.io/v1beta1
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kind: KubeletConfiguration
@@ -54,9 +55,10 @@ evictionHard:
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In this example, the kubelet is configured with the following settings:
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1. `address`: The kubelet will serve on IP address `192.168.0.8`.
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2. `port`: The kubelet will serve on port `20250`.
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3. `serializeImagePulls`: Image pulls will be done in parallel.
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4. `evictionHard`: The kubelet will evict Pods under one of the following conditions:
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1. `port`: The kubelet will serve on port `20250`.
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1. `serializeImagePulls`: Image pulls will be done in parallel.
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1. `evictionHard`: The kubelet will evict Pods under one of the following conditions:
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- When the node's available memory drops below 100MiB.
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- When the node's main filesystem's available space is less than 10%.
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- When the image filesystem's available space is less than 15%.
@@ -119,10 +121,9 @@ stored internally in the kubelet.
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This offers you flexibility in how you manage and combine kubelet configuration that comes from different sources.
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However, it's important to note that the behavior varies based on the data type of the configuration fields.
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Different data types in the kubelet configuration structure merge differently.
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See the [reference
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document](/docs/reference/node/kubelet-config-directory-merging.md) for more
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information.
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Different data types in the kubelet configuration structure merge differently. See the
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[reference document](/docs/reference/node/kubelet-config-directory-merging.md)
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for more information.
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### Kubelet configuration merging order
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@@ -135,8 +136,9 @@ On startup, the kubelet merges configuration from:
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{{< note >}}
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The config drop-in dir mechanism for the kubelet is similar but different from how the `kubeadm` tool allows you to patch configuration.
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The `kubeadm` tool uses a specific [patching strategy](/docs/setup/production-environment/tools/kubeadm/control-plane-flags/#patches) for its configuration,
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whereas the only patch strategy for kubelet configuration drop-in files is `replace`. The kubelet determines the order of merges based on sorting the **suffixes** alphanumerically,
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The `kubeadm` tool uses a specific [patching strategy](/docs/setup/production-environment/tools/kubeadm/control-plane-flags/#patches)
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for its configuration, whereas the only patch strategy for kubelet configuration drop-in files is `replace`.
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The kubelet determines the order of merges based on sorting the **suffixes** alphanumerically,
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and replaces every field present in a higher priority file.
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{{< /note >}}
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@@ -147,144 +149,144 @@ they can follow these steps to inspect the kubelet configuration:
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1. Start a proxy server using [`kubectl proxy`](/docs/reference/kubectl/generated/kubectl-commands#proxy) in your terminal.
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```bash
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kubectl proxy
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```
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Which gives output like:
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```bash
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Starting to serve on 127.0.0.1:8001
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```
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2. Open another terminal window and use `curl` to fetch the kubelet configuration.
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Replace `<node-name>` with the actual name of your node:
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```bash
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curl -X GET http://127.0.0.1:8001/api/v1/nodes/<node-name>/proxy/configz | jq .
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```
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```bash
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{
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"kubeletconfig": {
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"enableServer": true,
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"staticPodPath": "/var/run/kubernetes/static-pods",
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"syncFrequency": "1m0s",
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"fileCheckFrequency": "20s",
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"httpCheckFrequency": "20s",
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"address": "192.168.1.16",
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"port": 10250,
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"readOnlyPort": 10255,
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"tlsCertFile": "/var/lib/kubelet/pki/kubelet.crt",
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"tlsPrivateKeyFile": "/var/lib/kubelet/pki/kubelet.key",
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"rotateCertificates": true,
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"authentication": {
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"x509": {
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"clientCAFile": "/var/run/kubernetes/client-ca.crt"
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},
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"webhook": {
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"enabled": true,
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"cacheTTL": "2m0s"
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},
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"anonymous": {
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"enabled": true
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}
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},
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"authorization": {
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"mode": "AlwaysAllow",
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"webhook": {
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"cacheAuthorizedTTL": "5m0s",
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"cacheUnauthorizedTTL": "30s"
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}
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},
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"registryPullQPS": 5,
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"registryBurst": 10,
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"eventRecordQPS": 50,
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"eventBurst": 100,
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"enableDebuggingHandlers": true,
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"healthzPort": 10248,
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"healthzBindAddress": "127.0.0.1",
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"oomScoreAdj": -999,
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"clusterDomain": "cluster.local",
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"clusterDNS": [
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"10.0.0.10"
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],
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"streamingConnectionIdleTimeout": "4h0m0s",
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"nodeStatusUpdateFrequency": "10s",
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"nodeStatusReportFrequency": "5m0s",
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"nodeLeaseDurationSeconds": 40,
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"imageMinimumGCAge": "2m0s",
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"imageMaximumGCAge": "0s",
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"imageGCHighThresholdPercent": 85,
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"imageGCLowThresholdPercent": 80,
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"volumeStatsAggPeriod": "1m0s",
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"cgroupsPerQOS": true,
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"cgroupDriver": "systemd",
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"cpuManagerPolicy": "none",
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"cpuManagerReconcilePeriod": "10s",
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"memoryManagerPolicy": "None",
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"topologyManagerPolicy": "none",
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"topologyManagerScope": "container",
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"runtimeRequestTimeout": "2m0s",
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"hairpinMode": "promiscuous-bridge",
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"maxPods": 110,
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"podPidsLimit": -1,
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"resolvConf": "/run/systemd/resolve/resolv.conf",
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"cpuCFSQuota": true,
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"cpuCFSQuotaPeriod": "100ms",
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"nodeStatusMaxImages": 50,
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"maxOpenFiles": 1000000,
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"contentType": "application/vnd.kubernetes.protobuf",
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"kubeAPIQPS": 50,
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"kubeAPIBurst": 100,
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"serializeImagePulls": true,
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"evictionHard": {
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"imagefs.available": "15%",
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"memory.available": "100Mi",
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"nodefs.available": "10%",
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"nodefs.inodesFree": "5%"
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},
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"evictionPressureTransitionPeriod": "1m0s",
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"enableControllerAttachDetach": true,
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"makeIPTablesUtilChains": true,
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"iptablesMasqueradeBit": 14,
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"iptablesDropBit": 15,
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"featureGates": {
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"AllAlpha": false
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},
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"failSwapOn": false,
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"memorySwap": {},
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"containerLogMaxSize": "10Mi",
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"containerLogMaxFiles": 5,
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"configMapAndSecretChangeDetectionStrategy": "Watch",
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"enforceNodeAllocatable": [
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"pods"
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],
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"volumePluginDir": "/usr/libexec/kubernetes/kubelet-plugins/volume/exec/",
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"logging": {
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"format": "text",
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"flushFrequency": "5s",
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"verbosity": 3,
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"options": {
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"json": {
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"infoBufferSize": "0"
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}
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}
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},
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"enableSystemLogHandler": true,
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"enableSystemLogQuery": false,
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"shutdownGracePeriod": "0s",
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"shutdownGracePeriodCriticalPods": "0s",
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"enableProfilingHandler": true,
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"enableDebugFlagsHandler": true,
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"seccompDefault": false,
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"memoryThrottlingFactor": 0.9,
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"registerNode": true,
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"localStorageCapacityIsolation": true,
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"containerRuntimeEndpoint": "unix:///var/run/crio/crio.sock"
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}
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}
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```
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```bash
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kubectl proxy
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```
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Which gives output like:
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```none
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Starting to serve on 127.0.0.1:8001
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```
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1. Open another terminal window and use `curl` to fetch the kubelet configuration.
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Replace `<node-name>` with the actual name of your node:
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```bash
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curl -X GET http://127.0.0.1:8001/api/v1/nodes/<node-name>/proxy/configz | jq .
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```
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```json
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{
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"kubeletconfig": {
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"enableServer": true,
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"staticPodPath": "/var/run/kubernetes/static-pods",
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"syncFrequency": "1m0s",
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"fileCheckFrequency": "20s",
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"httpCheckFrequency": "20s",
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"address": "192.168.1.16",
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"port": 10250,
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"readOnlyPort": 10255,
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"tlsCertFile": "/var/lib/kubelet/pki/kubelet.crt",
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"tlsPrivateKeyFile": "/var/lib/kubelet/pki/kubelet.key",
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"rotateCertificates": true,
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"authentication": {
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"x509": {
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"clientCAFile": "/var/run/kubernetes/client-ca.crt"
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},
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"webhook": {
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"enabled": true,
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"cacheTTL": "2m0s"
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},
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"anonymous": {
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"enabled": true
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}
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},
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"authorization": {
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"mode": "AlwaysAllow",
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"webhook": {
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"cacheAuthorizedTTL": "5m0s",
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"cacheUnauthorizedTTL": "30s"
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}
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},
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"registryPullQPS": 5,
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"registryBurst": 10,
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"eventRecordQPS": 50,
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"eventBurst": 100,
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"enableDebuggingHandlers": true,
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"healthzPort": 10248,
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"healthzBindAddress": "127.0.0.1",
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"oomScoreAdj": -999,
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"clusterDomain": "cluster.local",
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"clusterDNS": [
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"10.0.0.10"
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],
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"streamingConnectionIdleTimeout": "4h0m0s",
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"nodeStatusUpdateFrequency": "10s",
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"nodeStatusReportFrequency": "5m0s",
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"nodeLeaseDurationSeconds": 40,
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"imageMinimumGCAge": "2m0s",
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"imageMaximumGCAge": "0s",
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"imageGCHighThresholdPercent": 85,
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"imageGCLowThresholdPercent": 80,
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"volumeStatsAggPeriod": "1m0s",
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"cgroupsPerQOS": true,
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"cgroupDriver": "systemd",
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"cpuManagerPolicy": "none",
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"cpuManagerReconcilePeriod": "10s",
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"memoryManagerPolicy": "None",
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"topologyManagerPolicy": "none",
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"topologyManagerScope": "container",
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"runtimeRequestTimeout": "2m0s",
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"hairpinMode": "promiscuous-bridge",
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"maxPods": 110,
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"podPidsLimit": -1,
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"resolvConf": "/run/systemd/resolve/resolv.conf",
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"cpuCFSQuota": true,
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"cpuCFSQuotaPeriod": "100ms",
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"nodeStatusMaxImages": 50,
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"maxOpenFiles": 1000000,
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"contentType": "application/vnd.kubernetes.protobuf",
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"kubeAPIQPS": 50,
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"kubeAPIBurst": 100,
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"serializeImagePulls": true,
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"evictionHard": {
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"imagefs.available": "15%",
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"memory.available": "100Mi",
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"nodefs.available": "10%",
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"nodefs.inodesFree": "5%"
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},
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"evictionPressureTransitionPeriod": "1m0s",
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"enableControllerAttachDetach": true,
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"makeIPTablesUtilChains": true,
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"iptablesMasqueradeBit": 14,
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"iptablesDropBit": 15,
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"featureGates": {
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"AllAlpha": false
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},
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"failSwapOn": false,
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"memorySwap": {},
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"containerLogMaxSize": "10Mi",
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"containerLogMaxFiles": 5,
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"configMapAndSecretChangeDetectionStrategy": "Watch",
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"enforceNodeAllocatable": [
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"pods"
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],
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"volumePluginDir": "/usr/libexec/kubernetes/kubelet-plugins/volume/exec/",
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"logging": {
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"format": "text",
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"flushFrequency": "5s",
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"verbosity": 3,
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"options": {
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"json": {
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"infoBufferSize": "0"
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}
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}
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},
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"enableSystemLogHandler": true,
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"enableSystemLogQuery": false,
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"shutdownGracePeriod": "0s",
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"shutdownGracePeriodCriticalPods": "0s",
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"enableProfilingHandler": true,
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"enableDebugFlagsHandler": true,
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"seccompDefault": false,
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"memoryThrottlingFactor": 0.9,
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"registerNode": true,
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"localStorageCapacityIsolation": true,
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"containerRuntimeEndpoint": "unix:///var/run/crio/crio.sock"
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}
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}
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```
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<!-- discussion -->
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@@ -294,4 +296,4 @@ curl -X GET http://127.0.0.1:8001/api/v1/nodes/<node-name>/proxy/configz | jq .
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[`KubeletConfiguration`](/docs/reference/config-api/kubelet-config.v1beta1/)
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reference.
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- Learn more about kubelet configuration merging in the
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[reference document](/docs/reference/node/kubelet-config-directory-merging.md).
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[reference document](/docs/reference/node/kubelet-config-directory-merging.md).

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