Basic Night Time Saving

One of the easiest ways and most common use cases for the Downscaler is using it for night time saving.

A good time to start saving resources at night could be from 6:00 PM to 8:00 AM during weekdays and on weekends.

Depending on your use case you can apply the night time saving clusterwide or on either namespace or workload level.

Clusterwide

In order to apply the wanted downtime clusterwide the GoKubeDownscaler has to know what downtime to use.

This can be done by either using an environment variable or a cli argument for the GoKubeDownscaler.

Environment Variable

If you want to add a clusterwide downtime with environment variables you can add them inside the values.yaml file.

There you have to add it to the configMap.extraConfig field:

values.yaml

# ...

configMap:
  name: go-kube-downscaler
  extraConfig: |
    DEFAULT_DOWNTIME: "Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"

# ...

Cli Argument

If you want to instead use a cli argument for the clusterwide downtime you can also add them inside the values.yaml file.

There you have to add it to the arguments field:

values.yaml

# ...

arguments:
  - --default-downtime="Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"
# ...

After setting the variable in one of the two ways all workloads in your cluster will be scaled down on every weekday from 6:00 PM to 8:00 AM and on weekends.

Namespace Level

To set this up for all workloads in a namespace you have to annotate the namespace with the wanted time span.

This can be done using a kubectl command or by editing the namespace's yaml manifest.

kubectl

Adding the downtime with kubectl is a single command:

kubectl annotate ns my-namespace downscaler/downtime="Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"

Edit manifest

If you want to edit the annotations manually with a yaml manifest file or by running kubectl edit ns my-namespace you have to add the following:

my-namespace.yaml

apiVersion: v1
kind: Namespace
metadata:
  name: my-namespace
  annotations:
    downscaler/downtime: "Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"

Now all workloads in my-namespace will be scaled down on every weekday from 6:00 PM to 8:00 AM and on weekends.

Workload Level

To set this up for individual workloads you have to set an annotation on each workload you want to scale down.

This can also be done by either using a kubectl command or by editing the workload's yaml manifest.

For demo purposes we will showcase this with a deployment.

kubectl

Adding the downtime with kubectl is a single command:

kubectl annotate deployment my-deployment downscaler/downtime="Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"

Edit manifest

If you want to edit the annotations manually with a yaml manifest file or by running kubectl edit deployment my-deployment you have to add the following:

my-deployment.yaml

apiVersion: apps/v1
kind: Deployment
metadata:
  name: my-deployment
  annotations:
    downscaler/downtime: "Mon-Fri 18:00-08:00 UTC, Sat-Sun 00:00-24:00 UTC"
spec:
  replicas: 3
  selector:
    matchLabels:
      app: nginx
  template:
    metadata:
      labels:
        app: nginx
    spec:
      containers:
      - name: nginx
        image: nginx:1.14.2
        ports:
        - containerPort: 80

Now your deployment my-deployment will be scaled down on every weekday from 6:00 PM to 8:00 AM and on weekends.