Google Config Sync vs Rancher Fleet

Google Config Sync keeps configuration and policies aligned across Kubernetes clusters by monitoring a source of truth and reconciling cluster state. It can sync files from Git repositories, OCI images and Helm charts, and apply Policy Controller constraints to registered and connected clusters. Namespace management supports multi-tenancy through namespace-scoped policies such as RBAC roles. Config Sync supports Autopilot and Standard GKE clusters, plus GKE-attached clusters including EKS and AKS. Clusters must be registered to a fleet before the service can be enabled. Its architecture combines hosted Google Cloud components with open-source components running on GKE. For OCI repositories, it can integrate with an admission webhook signature verification server to help ensure only trusted images are used. Config Sync is included with Google Kubernetes Engine at free, subject to a GKE-supported cluster version and fleet registration. It runs only on x86-based nodes, not Arm nodes. The drift-prevention admission webhook can use high memory and cause out-of-memory errors in clusters with many custom resources.

Rancher Fleet has no write-up on Specifiction yet; its figures are above.