Load Balancer Target Toggler

Use a Cloud Function on a schedule to toggle between multiple different backend services. Useful if you need to turn on and off a website on a schedule for some reason.

Example deployment

1. Deploy static sites into 2 separate publicly available GCS buckets. See site-off/ and site-on/ for examples.
2. Create backend bucket resources for each site. Note the name of the backend bucket resource, example below is using site-on and site-off.

# Create some names that we'll re-use for the resources
SITE_1=site-on
SITE_2=site-off

# Buckets where you deployed your static sites
SITE_1_BUCKET=<Bucket for site 1 starting with gs://>
SITE_2_BUCKET=<Bucket for site 2 starting with gs://>

gcloud compute backend-buckets create $SITE_1 --gcs-bucket-name $SITE_1_BUCKET
gcloud compute backend-buckets create $SITE_2 --gcs-bucket-name $SITE_2_BUCKET

3. Create PubSub topics that each of your Cloud Functions will use for the trigger.

gcloud pubsub topics create ${SITE_1}-topic
gcloud pubsub topics create ${SITE_2}-topic

4. Create Cloud Function for each site, setting the Load Balancer name and using the backend bucket resources created in Step 2.

LOAD_BALANCER=<Load balancer name>

gcloud functions deploy toggle-${SITE_1} \
    --source=./src/ \
    --entry-point main \
    --runtime python37 \
    --trigger-topic ${SITE_1}-topic \
    --set-env-vars LOAD_BALANCER=$LOAD_BALANCER,BACKEND_BUCKET=$SITE_1

gcloud functions deploy toggle-${SITE_2} \
    --source=./src/ \
    --entry-point main \
    --runtime python37 \
    --trigger-topic ${SITE_2}-topic \
    --set-env-vars LOAD_BALANCER=$LOAD_BALANCER,BACKEND_BUCKET=$SITE_2