Automated Operations

Manage and Automate Resource Operations

The k8s-cleaner does not just help users identify unused or unhealthy resources; it can also automate various operations to enhance the cluster's efficiency and management. For example, scale down Deployments/Daemonsets/Statefulsets based on a specified annotation.

The example below demonstrates how to automatically scale down Deployments, DaemonSets, and StatefulSets with a specified annotation at a desired time (e.g., 8 PM nightly). Before scaling down, the replica count is stored in another annotation for later retrieval. At the configured scale-up time (e.g., 8 AM), resources are restored, ensuring efficient resource utilization during off-peak hours.

Pause YAML Definition

Example - Pause

# The defintion:
# - runs at 8PM every day
# - finds all Deployments/StatefulSet/DaemonSet with
# annotation "pause-resume"
#
# For matched resources: 
# - stores current replicas in the annotation "previous-replicas"
# - sets their replicas to zero (scale down and pause)
#
---
    apiVersion: apps.projectsveltos.io/v1alpha1
kind: Cleaner
metadata:
  name: scale-down-deployment-statefulset-daemonset
spec:
  schedule: "* 20 * * *"
  action: Transform
  transform: |
    -- Set replicas to 0
    function transform()
      hs = {}

      if obj.metadata.annotations == nil then
        obj.metadata.annotations = {}
      end
      -- store in the annotation current replicas value
      obj.metadata.annotations["previous-replicas"] = tostring(obj.spec.replicas)

      -- reset replicas to 0
      obj.spec.replicas = 0

      hs.resource = obj
      return hs
    end  
  resourcePolicySet:
    resourceSelectors:
    - kind: Deployment
      group: apps
      version: v1
    - kind: StatefulSet
      group: "apps"
      version: v1
    - kind: DaemonSet
      group: "apps"
      version: v1
    aggregatedSelection: |
      function evaluate()
        local hs = {}

        -- returns true if object has annotaiton "pause-resume" 
        function hasPauseAnnotation(obj)
          if obj.metadata.annotations ~= nil then
            if obj.metadata.annotations["pause-resume"] then
              return true
            end

            return false
          end

          return
        end

        local resourceToPause = {}

        for _, resource in ipairs(resources) do
          if hasPauseAnnotation(resource) then
            table.insert(resourceToPause, {resource = resource})
          end
        end

        if #resourceToPause > 0 then
          hs.resources = resourceToPause
        end
        return hs
      end   

Resume YAML Definition

As we defined the pause action for specific resources, during peak times, we would like to scale the Kubernetes resources back to their initial state. To do that, we will use the resume YAML definition found below.

Example - Resume

# The cleaner:
# - runs at 8AM every day
# - finds all Deployments/StatefulSet/DaemonSet with
# annotation "pause-resume"
#
# For matched resources: 
# - gets the old replicas in the annotation "previous-replicas"
# - sets the replicas to such value found above (scale deployment/statefulset/daemonset up)
#
---
apiVersion: apps.projectsveltos.io/v1alpha1
kind: Cleaner
metadata:
  name: scale-up-deployment-statefulset-daemonset
spec:
  schedule: "* 8 * * *"
  action: Transform
  transform: |
    -- Set replicas to 0
    function transform()
      hs = {}
      if obj.metadata.annotations == nil then
    return
      end
      if not obj.metadata.annotations["previous-replicas"] then
    return
      end
      -- reset replicas
      obj.spec.replicas = tonumber(obj.metadata.annotations["previous-replicas"])
      hs.resource = obj
      return hs
    end  
  resourcePolicySet:
    resourceSelectors:
    - kind: Deployment
      group: apps
      version: v1
    - kind: StatefulSet
      group: "apps"
      version: v1
    - kind: DaemonSet
      group: "apps"
      version: v1
    aggregatedSelection: |
      function evaluate()
    local hs = {}

    -- returns true if object has annotaiton "pause-resume" 
    function hasPauseAnnotation(obj)
      if obj.metadata.annotations ~= nil then
        if obj.metadata.annotations["pause-resume"] then
          return true
        end

        return false
      end

      return false
    end

    local resourceToUnPause = {}

    for _, resource in ipairs(resources) do
      if hasPauseAnnotation(resource) then
        table.insert(resourceToUnPause, {resource = resource})
      end
    end

    if #resourceToUnPause > 0 then
      hs.resources = resourceToUnPause
    end
    return hs
      end