Q: What is the purpose of the `kube-proxy` and what happens if it goes down?
kube-proxy runs on every node (as a DaemonSet) and maintains network rules (iptables or ipvs) that implement Services. It watches the API...
#Kubernetes #Additional Kubernetes Scenarios (Q101-Q200) #L3 #Container Orchestration #K8s
🎙️ Candidate Opening & Architectural Context
""When troubleshooting Kubernetes, I always follow a structured layered model: Pod status -> Events -> Logs -> Network. When addressing this question, I walk the interviewer through our production incident runbook: isolating the blast radius, checking diagnostic logs and metrics, and applying a safe fix.""
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🛠️ Production Runbook & Step-by-Step Resolution
1️⃣
Initial Diagnostics & Root Cause Analysis
kube-proxy runs on every node (as a DaemonSet) and maintains network rules (iptables or ipvs) that implement Services. It watches the API server for Service/Endpoint changes and updates the rules.
- Existing connections continue (iptables rules still exist).
- New Service/Endpoint changes won't be applied on that node.
- New pods that need to reach a new Service may fail.
2️⃣
Remediation & Permanent Safeguards
If kube-proxy goes down on a node: Recovery: restart the kube-proxy pod. It re-syncs all rules.
- Pods on that node may route to removed pods.
💡 The Senior SRE Gold Nugget (Key Architectural Takeaway)
"Pro-Tip: Existing connections continue (iptables rules still exist).."
⚡ 60-Second Elevator Pitch Talking Points
- Existing connections continue (iptables rules still exist).
- New Service/Endpoint changes won't be applied on that node.
- New pods that need to reach a new Service may fail.
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