Kustomize Apply

Apply kustomize overlays to Kubernetes clusters with robust metadata extraction and precise workload tracking.

Features

• 🚀 Direct apply - kubectl apply with kustomize
• ⏳ Precise wait - Only waits for workloads in your manifests
• 📦 Namespace management - Auto-create namespaces
• 🔍 Dry run - Preview changes before applying
• 🎯 JSON outputs - Structured data for downstream use
• 🔐 Self-contained - Optional kubeconfig support

Usage

# Typical usage with kustomize-inspect
- name: Inspect overlay
  uses: skyhook-io/kustomize-inspect@v1
  id: inspect
  with:
    overlay_dir: deploy/overlays/production

- name: Apply to cluster
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/production
    namespace: ${{ steps.inspect.outputs.namespace }}
    workloads_json: ${{ steps.inspect.outputs.workloads_json }}

Inputs

Input	Description	Required	Default
overlay_dir	Path to kustomize overlay	✅	-
namespace	Target namespace (from Inspect)	✅	-
workloads_json	Workloads to track (from Inspect)	❌	[]
dry_run	Server-side dry run only	❌	false
validate	Client-side schema validation	❌	true
server_side	Use Server-Side Apply	❌	false
wait	Wait for workloads to be ready	❌	true
wait_timeout	Wait timeout in seconds	❌	300

Outputs

Output	Description	Example
applied_resources_json	kubectl apply output as JSON	["deployment.apps/api configured"]

Examples

Basic deployment with inspect

- name: Edit kustomization
  uses: skyhook-io/kustomize-edit@v1
  with:
    overlay_dir: deploy/overlays/staging
    image: backend
    tag: v1.2.3

- name: Inspect changes
  uses: skyhook-io/kustomize-inspect@v1
  id: inspect
  with:
    overlay_dir: deploy/overlays/staging

- name: Apply to cluster
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/staging
    namespace: ${{ steps.inspect.outputs.namespace }}
    workloads_json: ${{ steps.inspect.outputs.workloads_json }}

Dry run first

- name: Inspect
  uses: skyhook-io/kustomize-inspect@v1
  id: inspect
  with:
    overlay_dir: deploy/overlays/production

- name: Preview changes
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/production
    namespace: ${{ steps.inspect.outputs.namespace }}
    dry_run: true

- name: Apply if approved
  if: ${{ inputs.approved == 'true' }}
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/production
    namespace: ${{ steps.inspect.outputs.namespace }}
    workloads_json: ${{ steps.inspect.outputs.workloads_json }}

No wait (fire and forget)

- name: Quick apply
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/dev
    namespace: development
    wait: false

Server-side apply

- name: Apply with SSA
  uses: skyhook-io/kustomize-apply@v1
  with:
    overlay_dir: deploy/overlays/production
    namespace: ${{ steps.inspect.outputs.namespace }}
    server_side: true

Complete Workflow Example

jobs:
  deploy:
    steps:
      - name: Checkout
        uses: actions/checkout@v4
      
      - name: Login to cloud
        uses: skyhook-io/cloud-login@v1
        with:
          provider: aws
          region: us-east-1
          cluster: production
      
      - name: Update kustomization
        uses: skyhook-io/kustomize-edit@v1
        with:
          overlay_dir: deploy/overlays/production
          image: backend
          tag: ${{ inputs.tag }}
          annotations: |
            deployed-by:${{ github.actor }}
            deployment-id:${{ github.run_id }}
      
      - name: Inspect changes
        uses: skyhook-io/kustomize-inspect@v1
        id: inspect
        with:
          overlay_dir: deploy/overlays/production
      
      - name: Apply to cluster
        uses: skyhook-io/kustomize-apply@v1
        with:
          overlay_dir: deploy/overlays/production
          namespace: ${{ steps.inspect.outputs.namespace }}
          workloads_json: ${{ steps.inspect.outputs.workloads_json }}
          wait: true
          wait_timeout: 300
      
      - name: Show deployment info
        run: |
          echo "Deployed to namespace: ${{ steps.inspect.outputs.namespace }}"
          echo "Primary deployment: ${{ steps.inspect.outputs.primary_deployment }}"

How It Works

1. Builds manifests using kustomize build
2. Validates against kubectl schema (optional)
3. Ensures namespace exists
4. Applies manifests to cluster
5. Waits only for workloads provided via workloads_json

The action uses robust YAML parsing with yq to precisely track only the workloads in your manifests, avoiding brittle grep-based extraction.

Prerequisites

• kubectl configured with cluster access
• kustomize available
• jq for JSON processing
• Appropriate RBAC permissions

Notes

• Designed to work with kustomize-inspect for metadata
• No force or prune options (by design)
• Waits only for workloads you're actually deploying
• Works with any valid kustomization
• Supports server-side apply for large manifests