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Scenario #18
Cluster Management
K8s v1.25, Corporate proxy network
kubelet Unable to Pull Images Due to Proxy Misconfig
Nodes failed to pull images from DockerHub due to incorrect proxy environment configuration.
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What Happened
New kubelet config missed NO_PROXY=10.0.0.0/8,kubernetes.default.svc, causing internal DNS failures and image pull errors.
Diagnosis Steps
- 1kubectl describe pod showed ImagePullBackOff.
- 2Checked environment variables for kubelet via systemctl show kubelet.
- 3Verified lack of NO_PROXY.
Root Cause
Proxy config caused kubelet to route internal cluster DNS and registry traffic through the proxy.
Fix/Workaround
• Updated kubelet service file to include proper NO_PROXY.
• Restarted kubelet.Lessons Learned
Proxies in K8s require deep planning.
How to Avoid
- 1Always set NO_PROXY with service CIDRs and cluster domains.
- 2Test image pulls with isolated nodes first.