AWS Controllers for Kubernetes vs Spacelift

AWS Controllers for Kubernetes (ACK) lets Kubernetes users define AWS resources with Kubernetes custom resources. It periodically compares desired and actual AWS state and corrects drift. Documentation lists 74 service controllers, including S3, RDS, Lambda and DynamoDB. ACK supports declarative, version-controlled infrastructure alongside applications, across AWS accounts and regions. Read-only resources and read-only adoption support migration from other infrastructure-as-code tools. EKS users can install managed EKS Capabilities, where AWS handles controller installation and upgrades with automatic updates, auto-scaling and auto-tuning. Self-managed Helm installation runs on EKS, GKE, AKS, on-premises clusters and local environments, providing version and configuration control. AWS IAM authorizes controller access. Self-managed ACK costs nothing for Helm installation on Kubernetes 1.20+ on any Kubernetes cluster. EKS Capability pricing is hourly, with a base rate per enabled capability plus usage charges for each ACK resource managed.

Spacelift is an infrastructure-as-code orchestration platform that automates plans, applies, policy checks, and drift detection, while recording actions for governance and security. It integrates with Terraform, OpenTofu, Pulumi, CloudFormation, Kubernetes, Ansible, AWS CDK, Serverless, and Terragrunt. Source control connections include Bitbucket, GitHub, GitLab, and Azure DevOps; cloud and notification integrations include AWS, Azure, Google Cloud, Slack, and Microsoft Teams. Governance features include OPA-based policies for plans, approvals, notifications, and security controls, along with Spaces, Contexts, and role-based access control. Deployment options include managed SaaS, self-hosting on a cloud provider, on-premises and air-gapped deployment, and FedRAMP-authorized SaaS. The Free plan costs nothing and includes 2 users and 1 public worker. Starter + costs $20,000 a year as an annual subscription. The pricing FAQ says Starter+, Business, and Enterprise subscriptions are annual and that features or workers cannot be removed from annual subscriptions. Spacelift says customer data is encrypted at rest and in transit and that it holds SOC 2 Type II certification.