调整k8s node单节点可运行的pod突破110上限

  • 官方文档： https://kubernetes.io/zh-cn/docs/reference/config-api/kubelet-config.v1beta1/

使用 systemctl status kubelet 查看kubelet.service文件的路径

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可以看到配置文件在 /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf

[root@k8s-node1]# cat /usr/lib/systemd/system/kubelet.service.d/10-kubeadm.conf
# Note: This dropin only works with kubeadm and kubelet v1.11+
[Service]
Environment="KUBELET_KUBECONFIG_ARGS=--bootstrap-kubeconfig=/etc/kubernetes/bootstrap-kubelet.conf --kubeconfig=/etc/kubernetes/kubelet.conf"
Environment="KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml"
# This is a file that "kubeadm init" and "kubeadm join" generates at runtime, populating the KUBELET_KUBEADM_ARGS variable dynamically
EnvironmentFile=-/var/lib/kubelet/kubeadm-flags.env
# This is a file that the user can use for overrides of the kubelet args as a last resort. Preferably, the user should use
# the .NodeRegistration.KubeletExtraArgs object in the configuration files instead. KUBELET_EXTRA_ARGS should be sourced from this file.
EnvironmentFile=-/etc/sysconfig/kubelet
ExecStart=
ExecStart=/usr/bin/kubelet $KUBELET_KUBECONFIG_ARGS $KUBELET_CONFIG_ARGS $KUBELET_KUBEADM_ARGS $KUBELET_EXTRA_ARGS

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此文件我们发现 KUBELET_CONFIG_ARGS=--config=/var/lib/kubelet/config.yaml

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直接在KUBELET_CONFIG_ARGS 中添加参数即可

修改 /var/lib/kubelet/config.yaml 配置文件，在最下面添加一行 maxPods: xxx 我们修改下maxPods的数值，增大到300（具体按照你node节点资源情况设置，不建议设置的过大）

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修改完成之后重启下kubelet服务[不会影响正在运行的容器]

$ systemctl daemon-reload   
$ systemctl restart kubelet
  • 模拟调整pod 数量，运行500个pod；观察运行情况
#调整pod数量到500
[root@k8s-master01 system]# kubectl scale deployment my-nginx-test --replicas=500
deployment.apps/my-nginx-test scaled

#两个mode节点
[root@k8s-master01 system]# kubectl get nodes
NAME           STATUS   ROLES                  AGE   VERSION
k8s-master01   Ready    control-plane,master   24h   v1.20.15
k8s-master02   Ready    control-plane,master   24h   v1.20.15
k8s-node1      Ready    <none>                 24h   v1.20.15
k8s-node2      Ready    <none>                 53m   v1.20.15

#查看run 的pod 数量
[root@k8s-master01 system]# kubectl get pods | grep -i run | wc -l
500

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