Cluster Bare Autoscaler (CBA) automatically adjusts the size of a bare-metal Kubernetes cluster by powering nodes off or on based on real-time resource usage, while safely cordoning and draining nodes before shutdown.
This project is similar to the official Kubernetes Cluster Autoscaler, but with key differences:
- CBA does not terminate or bootstrap instances.
- Instead, it powers down and wakes up bare-metal nodes using mechanisms like Wake-on-LAN, or other pluggable power controllers.
- Nodes are cordoned and drained safely before shutdown.
CBA uses a chainable strategy model for deciding when to scale down a node. Strategies can be enabled individually or used together:
- Resource-aware strategy - checks CPU and memory requests and usage.
- Load average strategy - evaluates
/proc/loadavgvia a per-node metrics DaemonSet.
It is especially suited for self-managed data centers, homelabs, or cloud-like bare-metal environments.
For more details, see the docs/README.md
There's also a full blog series that describes the process of building CBA, how decisions were made, and implementation details are explained: blog series