Crossplane

Crossplane is the cloud-native framework for platform engineering. We trial it under Platform in the garden because it shows strong fit for internal developer platforms built on Kubernetes.

Blurb

Crossplane Is the Cloud-Native Framework for Platform Engineering

Summary

What it does: Crossplane extends Kubernetes to orchestrate any resource, not just containers. It builds control planes that expose declarative APIs backed by Providers and Configurations, letting platform teams compose infrastructure without bespoke controllers.

When to use: platform teams building an internal developer platform (IDP) that needs custom APIs with guardrails. Also cloud-native shops already running Kubernetes who want GitOps-friendly infrastructure. Also teams wanting to expose APIs that humans, automation, and AI agents can self-serve on.

When to skip: small footprint workloads where Terraform or direct cloud CLI is enough. Also teams without Kubernetes who do not want the operational cost of running a control plane. Also single-cloud shops needing only classic IaC with no custom API layer.

Ecosystem notes: Crossplane is an open source CNCF project built and commercially sponsored by Upbound. It overlaps with Kubernetes Resource Orchestrator (KRO) for composition of Kubernetes resources into higher-level APIs.

Details

Core concepts: Providers connect Crossplane to external services (cloud, DNS, database); Configurations bundle Providers and Compositions into installable packages; Compositions define how a Composite Resource (XR) maps to managed resources.

V2: Crossplane v2 shifts focus from infrastructure-only to control planes for applications, with new APIs for grouping of resources.

Promotion criteria: adopt only after a production workload shows real value over Terraform plus scripts. Pair with GitOps (ArgoCD) when Compositions and Claims live in repo.

Docs: docs.crossplane.io, github.com/crossplane/crossplane, why control planes.