k8s如何查看初始化时指定的--pod-network-cidr

可以通过以下命令查看在初始化Kubernetes集群时指定的`--pod-network-cidr`参数的值：

$ sudo kubeadm config view | grep podSubnet

如果该参数已经被指定，则会输出包含`podSubnet`的行，例如：

    podSubnet: 10.244.0.0/16

这个命令会输出kubeadm配置文件的内容，并使用grep命令查找`podSubnet`这个参数。

如果该命令没有返回任何结果，则说明在初始化Kubernetes集群时没有指定`--pod-network-cidr`参数。在这种情况下，需要使用网络插件的默认参数进行部署。请注意，如果在初始化Kubernetes集群时未指定`--pod-network-cidr`参数，则需要在安装网络插件时使用默认参数。

相关问题

4）kubeadm初始化集群： ①kubeadm 初始化集群，需要设置初始参数。 ② pod-network-cidr 指定pod使用的网段，设置值根据不同的网络 plugin选择，本任务 以. flannel 为例，设置值为172.16.0.0/16。

4）使用kubeadm初始化 Kubernetes 集群时，确实需要配置一些关键参数。其中 `pod-network-cidr` 是非常重要的一个，它代表了Pods将要连接到的网络范围。对于Flannel作为默认的网络插件，这个值通常会被设置为一个私有IP地址的CIDR块，比如 `172.16.0.0/16` 或 `192.168.0.0/16`。

设置这个参数的步骤通常是这样的：

1. 打开kubeadm配置文件，这通常是通过运行 `kubeadm init --config <path_to_config>` 来完成，`<path_to_config>` 是指你的自定义配置文件路径，如果没有指定则会生成一个默认配置。

2. 在配置文件中找到 `[Networking]` 节点，并更新 `podNetwork_cidr` 参数为你想要分配给Pods的网络地址范围。

apiVersion: kubeadm.k8s.io/v1beta2
kind: ClusterConfiguration
networking:
  podSubnet: 172.16.0.0/16 # 替换为你选择的CIDR

3. 使用 `kubeadm init` 命令，传入你的配置文件路径，开始初始化过程。

k8s 从新初始化集群

### 如何重新初始化 Kubernetes (k8s) 集群

#### 清理现有集群状态
为了安全地重新初始化 Kubernetes 集群，首先需要清理现有的集群状态。这可以通过 `kubeadm reset` 命令来完成：

sudo kubeadm reset

此命令会移除所有与 Kubernetes 相关的状态文件和服务。

#### 卸载旧版本组件
如果打算升级到新版本的 Kubernetes 或者完全重置环境，则还需要卸载已安装的相关软件包:

sudo apt-get remove -y kubeadm kubelet kubectl
sudo apt-get autoremove -y

对于 Red Hat/CentOS 用户应使用 yum 而不是 apt-get 来执行上述操作。

#### 安装所需依赖项并设置仓库源
确保系统上已经安装了必要的工具和库，并配置好官方 K8S APT/YUM 仓库以便获取最新的稳定版发布[^3]:

curl -fsSL https://packages.cloud.google.com/apt/doc/apt-key.gpg | sudo gpg --dearmor -o /usr/share/keyrings/cloud-archive-keyring.gpg
echo "deb [signed-by=/usr/share/keyrings/cloud-archive-keyring.gpg] http://apt.kubernetes.io/ kubernetes-xenial main" | sudo tee /etc/apt/sources.list.d/kubernetes.list
sudo apt-get update

请注意不同操作系统可能有不同的指令集用于添加软件源。

#### 更新至目标版本
根据需求更新到特定版本(这里假设要安装 v1.29):

sudo apt-get install -y kubelet=1.29.0-00 kubeadm=1.29.0-00 kubectl=1.29.0-00

再次提醒，在非 Debian 类 Linux 发行版下需调整相应的包管理器命令语法。

#### 初始化新的 Master 节点
一旦准备工作就绪就可以通过下面这条命令来进行 master 节点初始化工作；需要注意的是，这里的参数可能会依据实际场景有所变化，比如网络插件的选择等[^4]:

sudo kubeadm init --pod-network-cidr=10.244.0.0/16 --control-plane-endpoint="LOAD_BALANCER_DNS:LOAD_BALANCER_PORT"

其中 `--control-plane-endpoint` 参数指定了外部负载均衡器地址作为 API Server 访问入口，这对于构建 HA 架构非常重要[^2]。

#### 加入 Worker 节点
最后一步就是让 worker nodes 连接到这个新建好的 cluster 中去，通常情况下会在成功初始化之后得到一段类似于这样的输出提示信息用来加入其他节点[^1]:

kubeadm join LOAD_BALANCER_DNS:LOAD_BALANCER_PORT --token abcdef.0123456789abcdef \
    --discovery-token-ca-cert-hash sha256:befdfbcbfbcdbfbfdffbfddbbfdbfbdffdfbdfbffdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdfbdf