Post Renderer Patches

Sveltos offers a powerful capability called post-rendering. This allows you to make adjustments to generated manifests before deploying them to your managed clusters.

Imagine you're installing a Helm chart that lacks built-in label configuration. You want to add a enviroment: production label to all deployed instances. Here's where post-rendering shines! By using a post-render patch, you can achieve this without modifying the original chart.

The provided YAML snippet demonstrates this concept. It defines a ClusterProfile that targets deployments and injects a enviroment: production label using a strategic merge patch. This ensures all deployments receive the label during installation.

kind: ClusterProfile
metadata:
  name: deploy-kyverno
spec:
  clusterSelector:
    matchLabels:
      env: fv
  syncMode: Continuous
  helmCharts:
  - repositoryURL:    https://kyverno.github.io/kyverno/
    repositoryName:   kyverno
    chartName:        kyverno/kyverno
    chartVersion:     v3.1.4
    releaseName:      kyverno-latest
    releaseNamespace: kyverno
    helmChartAction:  Install
  policyRefs:
  - name: disallow-latest
    namespace: default
    kind: ConfigMap
  patches:
  - target:
      group: apps
      version: v1
      kind: Deployment
      name: ".*"
    patch: |
      - op: add
        path: /metadata/labels/environment
        value: production

This is yet another example

apiVersion: config.projectsveltos.io/v1beta1
kind: ClusterProfile
metadata:
  name: nginx
spec:
  clusterSelector:
    matchLabels:
      env: fv
  helmCharts:
  - chartName: nginx-stable/nginx-ingress
    chartVersion: 1.1.3
    helmChartAction: Install
    releaseName: nginx-latest
    releaseNamespace: nginx
    repositoryName: nginx-stable
    repositoryURL: https://helm.nginx.com/stable/
  patches:
  - patch: |-
      apiVersion: apps/v1
      kind: Deployment
      metadata:
        name:  nginx-latest-nginx-ingress-controller
      spec:
        template:
          spec:
            containers:
            - name: nginx-ingress
              imagePullPolicy: Always
              securityContext:
                readOnlyRootFilesystem: true
    target:
      group: apps
      kind: Deployment
      version: v1