Cross-Cluster Leader Election for Kubernetes Workloads Kubernetes-native leader election across multiple Kubernetes clusters using a shared PostgreSQL database and the client-go leader election …

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Cross-cluster leader election for Kubernetes workloads is typically limited to a single cluster because it relies on the Kubernetes API's Lease resource. This post demonstrates how to replace that backend with PostgreSQL by implementing the `resourcelock.Interface` from client-go, enabling coordination across multiple clusters. The custom PostgreSQL lock uses a single table with optimistic concurrency control (version field) to ensure only one instance holds leadership at a time. The approach preserves all standard client-go leader election semantics — lease duration, renew deadline, retry period, and callbacks — while removing the dependency on any single Kubernetes control plane. Trade-offs include PostgreSQL becoming a critical coordination dependency and the absence of strict fencing guarantees.

Cross-Cluster Leader Election for Kubernetes Workloads

pgleele/cmd/migrate/main.go at 9f809dc3c13c9858d12cbd93cba740e0974f5873 · akyriako/pgleele

Implementing the PostgreSQL resource lock

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Simulating leader election across multiple instances