add crossplane integration example

[cnvergence]

Summary

This PR add a Crossplane external integration document with a walkthrough.
The example provisions a MySQL database in the provider cluster using provider-sql and showcases kube-bind providing a simple way to request a database service from service catalog.
Kudos to colleagues for the presentation that helped to get some visible Crossplane resources that could be used in kube-bind as well.

Also, adds self signed issuer step in the cert manager example.

What Type of PR Is This?

/kind documentation

Related Issue(s)

Fixes #400

Release Notes

Added Crossplane integration document

[cnvergence]

To be clarified, should we just keep all these files inlined in the doc, or are we fine with having some directory for these resources?
Maybe an additional repo if more will come?

[xrstf]

Maybe an additional repo if more will come?

Seeing the examples currently being in the dev-only hack folder, I would say, yes, extra repo for examples. ^^

[cnvergence]

moved it to https://github.com/cnvergence/crossplane-kube-bind-setup for now

[mjudeikis]

@coderabbitai review please

[coderabbitai]

@mjudeikis I will review the changes in this PR.

---

🧠 Learnings used

Learnt from: mjudeikis
Repo: kube-bind/kube-bind PR: 351
File: contrib/kcp/test/e2e/binding.go:49-56
Timestamp: 2025-11-04T11:51:36.024Z
Learning: In kube-bind e2e tests (contrib/kcp/test/e2e/), workspace-level isolation prevents conflicts between test runs, making it safe to use hardcoded resource names like "test-binding" without risk of concurrent test collisions.

✅ Actions performed

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[mjudeikis]

in general can we just create a folder examples in root and add all yamls in there? Your repo has newer things than this document already.

[mjudeikis]

Seeing the examples currently being in the dev-only hack folder, I would say, yes, extra repo for examples. ^^

Lets not add yet-another-repo to manage until we get things stable. Just add examples in the root dir

[Copilot]

Pull request overview

This PR adds comprehensive Crossplane integration documentation and example files demonstrating how to use kube-bind with Crossplane for managed database provisioning. The example showcases a MySQL database service provisioned using Crossplane's provider-sql in a provider cluster, which is then exported and consumed via kube-bind. The PR also includes minor improvements to the cert-manager integration documentation.

Key changes:

• Complete Crossplane integration walkthrough with MySQL database example using XRD, Composition, and provider-sql
• Example YAML manifests for all components needed to run the integration
• Addition of self-signed issuer setup instructions in the cert-manager documentation

Reviewed changes

Copilot reviewed 11 out of 12 changed files in this pull request and generated 8 comments.

Show a summary per file

File	Description
docs/content/usage/integrations/crossplane.md	New comprehensive guide for integrating kube-bind with Crossplane, including step-by-step MySQL database provisioning example
docs/content/usage/integrations/cert-manager.md	Updated with self-signed issuer setup step and fixed trailing whitespace
docs/content/usage/integrations/.pages	Added crossplane.md to navigation
examples/crossplane/xrd/xrd-db.yaml	Defines the MySQLDatabase CompositeResourceDefinition (XRD) with kube-bind export label
examples/crossplane/xrd/composition.yaml	Comprehensive Composition using Go templating to orchestrate MySQL database, user, and secret resources
examples/crossplane/xrd/function-go-templating.yaml	Crossplane Function definition for Go templating support
examples/crossplane/mysql.yaml	Kubernetes manifests for deploying MySQL server (Deployment, PV, PVC, Service)
examples/crossplane/db-provider/provider.yaml	Crossplane provider-sql installation manifest
examples/crossplane/db-provider/config.yaml	ProviderConfig for connecting to MySQL instance
examples/crossplane/db-apiserviceexporttemplate.yaml	APIServiceExportTemplate to export MySQLDatabase API with secret permission claims
examples/crossplane/consumer-db.yaml	Example consumer database request manifest

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[Copilot]

Pull request overview

Copilot reviewed 11 out of 12 changed files in this pull request and generated 3 comments.

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[mjudeikis]

few nits

[mjudeikis]

/lgtm
/approve