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Cluster Manifests Documentation

This document describes the Kubernetes manifests used to set up the Open Service Portal platform infrastructure.

Overview​

The manifests in scripts/cluster-manifests/ are applied by the setup-cluster.sh script to configure:

  • Crossplane providers for infrastructure management
  • Composition functions for resource transformation
  • Environment configurations for platform settings
  • GitOps integration with Flux

Manifest Files​

Crossplane Providers​

provider-kubernetes​

  • File: crossplane-provider-kubernetes.yaml
  • Purpose: Manages Kubernetes resources (ConfigMaps, Services, Deployments)
  • Version: v0.14.0
  • Config: crossplane-provider-kubernetes-config.yaml - Uses injected identity
  • RBAC: crossplane-provider-kubernetes-rbac.yaml - Grants cluster-admin for namespace creation

provider-helm​

  • File: crossplane-provider-helm.yaml
  • Purpose: Deploys Helm charts (PostgreSQL, Redis, applications)
  • Version: v0.20.0
  • Config: crossplane-provider-helm-config.yaml - Uses injected identity

provider-cloudflare​

  • File: crossplane-provider-cloudflare.yaml
  • Purpose: Manages Cloudflare resources (DNS records, zones)
  • Version: ghcr.io/cdloh/provider-cloudflare:v0.1.0
  • Config: References cloudflare-credentials secret (created by config-openportal.sh)

Composition Functions​

File: crossplane-functions.yaml

Functions transform resource specifications in the composition pipeline:

  • function-go-templating (v0.4.0) - Go templates for flexible resource generation
  • function-patch-and-transform (v0.4.0) - Traditional patching and transformation
  • function-auto-ready (v0.2.0) - Automatically mark resources as ready
  • function-environment-configs (v0.4.0) - Load shared environment configurations

Environment Configurations​

File: environment-configs.yaml

Platform-wide shared configuration accessible to all compositions:

  • dns-config - DNS zone and provider settings (defaults to localhost/mock)
  • Can be overridden for production environments

GitOps Integration​

File: flux-catalog.yaml

Configures Flux to:

  • Watch the catalog repository for Crossplane templates
  • Automatically sync and apply template updates
  • Enable GitOps workflow for infrastructure

How Functions Work with Providers​

Functions and providers work together in a pipeline:

  1. Functions transform data - Manipulate YAML/JSON specifications
  2. Providers create resources - Take specs and create actual resources
  3. They're complementary - Functions prepare the "recipe", providers do the "cooking"

Example: Using provider-kubernetes with go-templating​

pipeline:
  - step: create-service
    functionRef:
      name: function-go-templating
    input:
      apiVersion: gotemplating.crossplane.io/v1beta1
      kind: GoTemplate
      source: Inline
      inline:
        template: |
          apiVersion: kubernetes.crossplane.io/v1alpha2
          kind: Object  # Handled by provider-kubernetes
          spec:
            forProvider:
              manifest:
                apiVersion: v1
                kind: Service
                metadata:
                  name: {{ .observed.composite.resource.metadata.name }}

Example: Using provider-helm with go-templating​

pipeline:
  - step: deploy-postgresql
    functionRef:
      name: function-go-templating
    input:
      apiVersion: gotemplating.crossplane.io/v1beta1
      kind: GoTemplate
      source: Inline
      inline:
        template: |
          apiVersion: helm.crossplane.io/v1beta1
          kind: Release  # Handled by provider-helm
          metadata:
            name: {{ .observed.composite.resource.metadata.name }}-postgresql
          spec:
            forProvider:
              chart:
                name: postgresql
                repository: https://charts.bitnami.com/bitnami

Best Practices​

  1. Use go-templating for new compositions - More modern and flexible than patch-and-transform
  2. Load environment configs - Use function-environment-configs for shared settings
  3. Keep providers minimal - Only install providers you actually need
  4. Version pin functions - Specify exact versions for reproducibility

Restaurant Analogy​

To understand how these components work together:

  • Providers = Kitchen equipment (ovens, grills, fryers)
  • Functions = Recipe techniques (chopping, mixing, seasoning)
  • Environment Configs = House standards (portion sizes, seasoning levels)
  • Flux = Supply chain automation (automatic restocking)

You use the same techniques (functions) with different equipment (providers) to prepare dishes (resources) according to house standards (configs).