kubernetes network_error ai_generated partial

Error from server: error dialing backend: dial tcp 10.0.0.5:10250: connect: connection refused

ID: kubernetes/exec-in-pod-failed-unable-to-upgrade-connection

Also available as: JSON · Markdown · 中文
75%Fix Rate
80%Confidence
1Evidence
2024-01-20First Seen

Version Compatibility

VersionStatusIntroducedDeprecatedNotes
kubectl v1.27.0 active — — —
kubelet v1.27.0 active — — —
kubelet v1.29.0 active — — —
Kubernetes v1.28.0 active — — —

Root Cause

The kubelet on the node is not listening on the expected port (10250) or is unreachable due to network issues, preventing kubectl exec/attach/logs.

generic

中文

节点上的 kubelet 未在预期端口（10250）上监听，或因网络问题无法访问，导致 kubectl exec/attach/logs 失败。

Official Documentation

https://kubernetes.io/docs/reference/command-line-tools-reference/kubelet/

Workarounds

  1. 70% success SSH into the node and restart kubelet: `ssh node-user@node-ip 'sudo systemctl restart kubelet'`. 
    SSH into the node and restart kubelet: `ssh node-user@node-ip 'sudo systemctl restart kubelet'`.
  2. 80% success Check if kubelet is running and on the correct port: `ssh node-user@node-ip 'sudo netstat -tulpn | grep 10250'`. If not, check kubelet config for `--port` flag. 
    Check if kubelet is running and on the correct port: `ssh node-user@node-ip 'sudo netstat -tulpn | grep 10250'`. If not, check kubelet config for `--port` flag.
  3. 75% success If firewall is blocking, verify network policies or cloud firewall rules allow traffic from control plane to node port 10250. 
    If firewall is blocking, verify network policies or cloud firewall rules allow traffic from control plane to node port 10250.

中文步骤

  1. SSH 到节点并重启 kubelet：`ssh node-user@node-ip 'sudo systemctl restart kubelet'`。
  2. 检查 kubelet 是否在运行并在正确端口上：`ssh node-user@node-ip 'sudo netstat -tulpn | grep 10250'`。如果没有，检查 kubelet 配置中的 `--port` 参数。
  3. 如果防火墙阻止，检查网络策略或云防火墙规则是否允许从控制平面到节点端口 10250 的流量。

Dead Ends

Common approaches that don't work:

  1. Restarting the pod, assuming it's a container issue 90% fail

    The error is node-level, not pod-level; restarting the pod won't fix kubelet connectivity.

  2. Checking pod logs via kubectl logs, which also fails with the same error 80% fail

    All kubectl commands that require kubelet interaction (exec, logs, attach) will fail identically.