Crossplane: Manage Cloud Infrastructure from Kubernetes

Use Crossplane to provision AWS, Azure, and GCP resources with Kubernetes manifests. The universal cloud control plane for platform engineering teams.

Luca Berton · AI Advisor & Architect

Published June 5, 2026 · 1 min read

What Is Crossplane?

Crossplane extends Kubernetes to manage any cloud resource using kubectl. Provision RDS databases, S3 buckets, Azure VNets, and GCP BigQuery — all with Kubernetes manifests. CNCF Graduated project.

How It Works

┌──────────────────────────────────────────┐
│         Kubernetes Cluster               │
│                                          │
│  ┌──────────────────────────────────┐   │
│  │      Crossplane Controller        │   │
│  └───────────────┬──────────────────┘   │
│                  │                       │
│  ┌───────────────┼───────────────────┐  │
│  │               │                   │  │
│  ▼               ▼                   ▼  │
│ AWS Provider  Azure Provider  GCP Provider
│  │               │                   │  │
└──┼───────────────┼───────────────────┼──┘
   │               │                   │
   ▼               ▼                   ▼
┌──────┐    ┌───────────┐    ┌──────────┐
│ AWS  │    │   Azure   │    │   GCP    │
│ RDS  │    │ CosmosDB  │    │ BigQuery │
│ S3   │    │ AKS       │    │ GKE     │
└──────┘    └───────────┘    └──────────┘

Provision Cloud Resources

RDS Database

apiVersion: rds.aws.upbound.io/v1beta2
kind: Instance
metadata:
  name: production-db
spec:
  forProvider:
    region: eu-west-1
    instanceClass: db.r6g.xlarge
    engine: postgres
    engineVersion: "16"
    allocatedStorage: 100
    storageType: gp3
    masterUsername: admin
    masterPasswordSecretRef:
      name: db-password
      namespace: crossplane-system
      key: password
    vpcSecurityGroupIds:
      - sg-xxx
    dbSubnetGroupName: production-subnet-group
  providerConfigRef:
    name: aws-production

S3 Bucket

apiVersion: s3.aws.upbound.io/v1beta2
kind: Bucket
metadata:
  name: ml-artifacts
spec:
  forProvider:
    region: eu-west-1
    tags:
      Environment: production
      Team: ml-platform

Compositions (Platform Abstractions)

Create high-level APIs that hide cloud complexity:

# Define what a "Database" means for your org
apiVersion: apiextensions.crossplane.io/v1
kind: CompositeResourceDefinition
metadata:
  name: databases.platform.company.com
spec:
  group: platform.company.com
  names:
    kind: Database
    plural: databases
  versions:
    - name: v1
      schema:
        openAPIV3Schema:
          properties:
            spec:
              properties:
                size:
                  type: string
                  enum: [small, medium, large]
                engine:
                  type: string
                  enum: [postgres, mysql]
---
# Teams request a database simply:
apiVersion: platform.company.com/v1
kind: Database
metadata:
  name: orders-db
spec:
  size: medium
  engine: postgres

The Composition translates this into RDS + security groups + subnet groups + parameter groups automatically.

Crossplane vs Terraform

Feature	Crossplane	Terraform
Reconciliation	✅ Continuous (K8s controller)	❌ Run-once
Drift detection	✅ Automatic (every 60s)	❌ Manual `terraform plan`
State	Kubernetes etcd	Separate state file
Language	YAML (K8s manifests)	HCL
Self-service	✅ Teams use kubectl	❌ Requires Terraform access
GitOps	✅ Native (Argo CD/Flux)	⚠️ Requires wrapper
Multi-tenancy	✅ Namespaces + RBAC	⚠️ Workspaces

Key insight: Crossplane continuously reconciles — if someone manually changes a resource in the AWS console, Crossplane fixes it automatically. Terraform only detects drift on the next plan.

When to Use Crossplane

✅ Platform team providing self-service infrastructure
✅ GitOps workflow (Argo CD manages everything)
✅ Multi-cloud or hybrid cloud
✅ Want continuous drift detection
✅ Kubernetes-native teams

When to Use Terraform Instead

✅ Small team, simple infrastructure
✅ Team already proficient in HCL
✅ No Kubernetes cluster to run Crossplane
✅ One-time provisioning (not continuous)