k3s

Question

我将一个 k3s 集群部署到 2 raspberry pi 4. 一个作为 master，第二个作为 worker 使用脚本 k3s 提供以下选项：

对于主节点：

curl -sfL https://get.k3s.io | INSTALL_K3S_EXEC='server --bind-address 192.168.1.113 (which is the master node ip)' sh -

至代理节点：

curl -sfL https://get.k3s.io | \
                K3S_URL=https://192.168.1.113:6443 \
                K3S_TOKEN=<master-token> \
                INSTALL_K3S_EXEC='agent' sh-

似乎一切正常，但 kubectl top nodes returns 以下内容：

NAME          CPU(cores)   CPU%   MEMORY(bytes)   MEMORY%     
k3s-master    137m         3%     1285Mi          33%         
k3s-node-01   <unknown>                           <unknown>               <unknown>               <unknown>

我也尝试部署 k8s 仪表板，根据 the docs 中的内容，但它无法工作，因为它无法到达指标服务器并出现超时错误：

"error trying to reach service: dial tcp 10.42.1.11:8443: i/o timeout"

我在 pod 日志中看到很多错误：

2021/09/17 09:24:06 Metric client health check failed: the server is currently unable to handle the request (get services dashboard-metrics-scraper). Retrying in 30 seconds.
2021/09/17 09:25:06 Metric client health check failed: the server is currently unable to handle the request (get services dashboard-metrics-scraper). Retrying in 30 seconds.
2021/09/17 09:26:06 Metric client health check failed: the server is currently unable to handle the request (get services dashboard-metrics-scraper). Retrying in 30 seconds.
2021/09/17 09:27:06 Metric client health check failed: the server is currently unable to handle the request (get services dashboard-metrics-scraper). Retrying in 30 seconds.

来自 metrics-server 窗格的日志：

elet_summary:k3s-node-01: unable to fetch metrics from Kubelet k3s-node-01 (k3s-node-01): Get https://k3s-node-01:10250/stats/summary?only_cpu_and_memory=true: dial tcp 192.168.1.106:10250: connect: no route to host
E0917 14:03:24.767949       1 manager.go:111] unable to fully collect metrics: unable to fully scrape metrics from source kubelet_summary:k3s-node-01: unable to fetch metrics from Kubelet k3s-node-01 (k3s-node-01): Get https://k3s-node-01:10250/stats/summary?only_cpu_and_memory=true: dial tcp 192.168.1.106:10250: connect: no route to host
E0917 14:04:24.767960       1 manager.go:111] unable to fully collect metrics: unable to fully scrape metrics from source kubelet_summary:k3s-node-01: unable to fetch metrics from Kubelet k3s-node-01 (k3s-node-01): Get https://k3s-node-01:10250/stats/summary?only_cpu_and_memory=true: dial tcp 192.168.1.106:10250: connect: no route to host

Answer 1

为了更好的可见性，将其从评论中移出。

创建小型集群后，我无法重现此行为，metrics-server 两个节点都运行良好，kubectl top nodes 显示了两个可用节点的信息和指标（我认为这需要一些时间是时候开始收集指标了）。

这导致故障排除步骤为什么它不起作用。检查 metrics-server 日志是解决这个问题的最有效方法：

$ kubectl logs metrics-server-58b44df574-2n9dn -n kube-system

根据日志，将有不同的步骤继续，例如在上面的评论中：

首先是 no route to host，这与网络有关并且无法解析主机名
then i/o timeout 这意味着路由存在，但服务没有响应。这可能是由于防火墙阻止了某些 ports/sources，kubelet 不是运行（侦听端口 10250），或者因为它出现在 OP 上，所以 kubelet 有问题 ntp 这影响了证书和连接。
错误在其他情况下可能会有所不同，找到错误并根据错误进一步排除故障很重要。

k3s - 指标服务器不适用于工作节点

k3s - Metrics server doesn't work for worker nodes

kubernetes

metrics-server