Update Resources

Introduction to Resource Update

Beyond removing stale resources, the k8s-cleaner can also facilitate in the dynamic update of existing resource configurations.

The capability allows users to modify resource specifications based on specific criteria, ensuring alignment with evolving requirements and maintaining resource consistency.

Example - Resource Update

Consider the scenario where we want to update Service objects in the foo namespace to use version2 apps.

1. The evaluate function allows users to select resources, Services in the foo namespace pointing to version1 apps.
2. The trasnform function will change the matching resources, by updating the obj.spec.selector["app"] to version2.

---
apiVersion: apps.projectsveltos.io/v1alpha1
kind: Cleaner
metadata:
  name: cleaner-sample3
spec:
  schedule: "* 0 * * *"
  resourcePolicySet:
    resourceSelectors:
    - namespace: foo
      kind: Service
      group: ""
      version: v1
      evaluate: |
        -- Define how resources will be selected 
        function evaluate()
        hs = {}
        hs.matching = false
        if obj.spec.selector ~= nil then
          if obj.spec.selector["app"] == "version1" then
            hs.matching = true
          end
        end
        return hs
        end
  action: Transform # Update matching resources
  transform: |
      -- Define how resources will be updated
      function transform()
      hs = {}
      obj.spec.selector["app"] = "version2"
      hs.resource = obj
      return hs
      end