kube_node
是集群中运行工作负载的节点,前置条件需要先部署好kube_master
节点,它需要部署如下组件:
cat playbooks/05.kube-node.yml
- hosts: kube_node
roles:
- { role: kube-lb, when: "inventory_hostname not in groups['kube_master']" }
- { role: kube-node, when: "inventory_hostname not in groups['kube_master']" }
- kube-lb:由nginx裁剪编译的四层负载均衡,用于将请求转发到主节点的 apiserver服务
- kubelet:kube_node上最主要的组件
- kube-proxy: 发布应用服务与负载均衡
因为后续需要用 DaemonSet Pod
方式运行k8s网络插件,所以kubelet.server服务必须开启cni相关参数,并且提供cni网络配置文件
- 根据官方建议独立使用 kubelet 配置文件,详见roles/kube-node/templates/kubelet-config.yaml.j2
- 必须先创建工作目录
/var/lib/kubelet
[Unit]
Description=Kubernetes Kubelet
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
[Service]
WorkingDirectory=/var/lib/kubelet
ExecStartPre=/bin/mount -o remount,rw '/sys/fs/cgroup'
{% if KUBE_RESERVED_ENABLED == "yes" or SYS_RESERVED_ENABLED == "yes" %}
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpu/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpuacct/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpuset/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/memory/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/pids/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/systemd/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpu/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpuacct/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/cpuset/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/memory/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/pids/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/systemd/system.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/hugetlb/podruntime.slice
ExecStartPre=/bin/mkdir -p /sys/fs/cgroup/hugetlb/system.slice
{% endif %}
ExecStart={{ bin_dir }}/kubelet \
--config=/var/lib/kubelet/config.yaml \
--container-runtime-endpoint=unix:///run/containerd/containerd.sock \
--hostname-override={{ K8S_NODENAME }} \
--kubeconfig=/etc/kubernetes/kubelet.kubeconfig \
--root-dir={{ KUBELET_ROOT_DIR }} \
--v=2
Restart=always
RestartSec=5
[Install]
WantedBy=multi-user.target
- --ExecStartPre=/bin/mkdir -p xxx 对于某些系统(centos7)cpuset和hugetlb 是默认没有初始化system.slice 的,需要手动创建,否则在启用--kube-reserved-cgroup 时会报错Failed to start ContainerManager Failed to enforce System Reserved Cgroup Limits
- 关于kubelet资源预留相关配置请参考 https://kubernetes.io/docs/tasks/administer-cluster/reserve-compute-resources/
该步骤已经在 deploy节点完成,roles/deploy/tasks/main.yml
- 生成的kube-proxy.kubeconfig 配置文件需要移动到/etc/kubernetes/目录,后续kube-proxy服务启动参数里面需要指定
[Unit]
Description=Kubernetes Kube-Proxy Server
Documentation=https://github.com/GoogleCloudPlatform/kubernetes
After=network.target
[Service]
WorkingDirectory=/var/lib/kube-proxy
ExecStart={{ bin_dir }}/kube-proxy \
--config=/var/lib/kube-proxy/kube-proxy-config.yaml
Restart=always
RestartSec=5
LimitNOFILE=65536
[Install]
WantedBy=multi-user.target
请注意 kube-proxy-config 文件的注释说明
systemctl status kubelet # 查看状态
systemctl status kube-proxy
journalctl -u kubelet # 查看日志
journalctl -u kube-proxy
运行 kubectl get node
可以看到类似
NAME STATUS ROLES AGE VERSION
192.168.1.42 Ready <none> 2d v1.9.0
192.168.1.43 Ready <none> 2d v1.9.0
192.168.1.44 Ready <none> 2d v1.9.0