Crossplane Composite Resource Stuck in Syncing

In this tutorial, you'll learn about Crossplane Composite Resource Stuck in Syncing. We cover key concepts, practical examples, and best practices.

A CompositeResource (XR) you created remains in the 'Syncing' state indefinitely or is never reconciled.

Wrong ❌

apiVersion: example.org/v1alpha1
kind: XMyDatabase
metadata:
  name: my-db
spec:
  parameters:
    version: "13"
    storageGB: 100
    # Missing region parameter required by composition

Wrong Output

NAME     SYNCED   READY   AGE
my-db   False    False   5m
Events:
  Warning ComposeResources: cannot compose resources: reference Composition/invalid-db-composition not found

Right ✅

apiVersion: example.org/v1alpha1
kind: XMyDatabase
metadata:
  name: my-db
spec:
  parameters:
    region: us-east-1
    version: "13"
    storageGB: 100
    engine: postgres
  compositionRef:
    name: db-composition
  compositionSelector:
    matchLabels:
      provider: aws
      engine: postgres

Right Output

NAME     SYNCED   READY   AGE
my-db   True     True    2m
Ready state: Resources composed and ready for use

Prevention

• Always verify that the compositionRef or compositionSelector matches an existing Composition resource.
• Ensure all required parameter fields defined in the XRD are provided in the composite resource.
• Check the Crossplane provider is installed and functional: kubectl get providers.
• Use compositionSelector with labels for flexible composition matching.
• Monitor composite resource events: kubectl describe .

DodaTech applies similar defensive patterns across Doda Browser, DodaZIP, and Durga Antivirus Pro infrastructure for production reliability.

Common Mistakes with composite resource

1. Overlapping type class instances that cause GHC to reject the program with ambiguous dispatch errors
2. Non-exhaustive pattern matches that compile with warnings then crash at runtime
3. Misunderstanding that String is [Char] with poor performance for large text operations

These mistakes appear frequently in real-world CROSSPLANE code. DodaTech's contributors have identified these patterns through analysis of open-source projects and production systems.

Practice Exercise

Write a pure function that safely divides two integers using Maybe, then test it with edge cases like division by zero and negative numbers.

This exercise reinforces the concepts covered in this guide. Try implementing it before checking online solutions.

FAQ

This quick fix is part of the DodaTech infrastructure engineering series. Learn more at DodaTech tutorials.