karpenter_enabled

Description

The karpenter_enabled parameter is a bidirectional toggle that deploys or removes Karpenter node autoscaling on your AWS Rack. When enabled, Karpenter manages workload and build node provisioning through NodePools and EC2NodeClasses, replacing Cluster Autoscaler for those tiers.

Requires karpenter_auth_mode=true. Both can be set in a single call:

$ convox rack params set karpenter_auth_mode=true karpenter_enabled=true -r rackName
Setting parameters... OK

Default Value

The default value is false.

Use Cases

• Faster node scaling: Karpenter provisions nodes in seconds rather than the multi-minute Cluster Autoscaler feedback loop.
• Cost optimization: Karpenter selects the cheapest instance type that satisfies pod requirements, with automatic spot-to-on-demand fallback.
• Scale-to-zero builds: Build nodes are provisioned on-demand and removed after builds complete, eliminating idle build node costs.

Setting the Parameter

$ convox rack params set karpenter_enabled=true -r rackName
Setting parameters... OK

To disable Karpenter:

$ convox rack params set karpenter_enabled=false -r rackName
Setting parameters... OK

Additional Information

• Bidirectional. Can be toggled on and off freely. Disabling cleanly removes all Karpenter resources and restores Cluster Autoscaler.
• Requires karpenter_auth_mode=true. If karpenter_auth_mode is not already enabled, include it in the same call.
• Additional node groups constraint. All existing additional_node_groups_config entries must have dedicated=true when Karpenter is enabled.
• What it deploys: Karpenter controller, workload NodePool + EC2NodeClass, build NodePool (if build_node_enabled=true), IAM roles, SQS interruption queue, and EventBridge rules.

See Also

• Karpenter for the full Karpenter configuration reference
• karpenter_auth_mode for the one-way EKS prerequisite migration