blog-10-setup.sh

#!/bin/bash
set -e

INSTANCE_NAME=ps-media
ZONE=europe-west3-c
PRESTASHOP_WEBSITE=http://www.example.com
MEDIA_SERVER_NAME=cdn.example.com

# download vm-stratup-script.sh
curl https://gist.githubusercontent.com/gabihodoroaga/43731b8ad9c63f3fe54913acff5e79c2/raw \
    --output vm-stratup-script.sh

# replace our variables inside the script
sed -i 's/PRESTASHOP_WEBSITE/'"$PRESTASHOP_WEBSITE"'/g' vm-stratup-script.sh
sed -i 's/MEDIA_SERVER_NAME/'"$MEDIA_SERVER_NAME"'/g' vm-stratup-script.sh

# create the instance template
gcloud compute instance-templates create-with-container $INSTANCE_NAME-template \
    --container-image gcr.io/cloud-marketplace/google/nginx1:1.15 \
    --machine-type f1-micro \
    --tags $INSTANCE_NAME-http \
    --metadata-from-file startup-script=vm-startup-script.sh \
    --container-mount-host-path host-path=/var/nginx.conf,mount-path=/etc/nginx/nginx.conf,mode=ro

# create the instance group
gcloud compute instance-groups managed create $INSTANCE_NAME-instance-group \
    --template $INSTANCE_NAME-template \
    --size 1 \
    --zone $ZONE

# create the health check
gcloud compute health-checks create http $INSTANCE_NAME-health-check \
    --request-path / \
    --port 80 \
    --check-interval 60s \
    --healthy-threshold 1 \
    --timeout 5s \
    --unhealthy-threshold 5 \
    --host $MEDIA_SERVER_NAME

# create the firewall rule
gcloud compute firewall-rules create $INSTANCE_NAME-allow-health-check \
    --allow tcp:80 \
    --source-ranges 130.211.0.0/22,35.191.0.0/16 \
    --target-tags $INSTANCE_NAME-http

# add the health check to the intstance group
gcloud compute instance-groups managed update $INSTANCE_NAME-instance-group \
    --health-check $INSTANCE_NAME-health-check \
    --initial-delay 300 \
    --zone $ZONE
 
 # create a backend service
gcloud compute backend-services create $INSTANCE_NAME-lb-backend \
  --http-health-checks $INSTANCE_NAME-health-check \
  --port-name http \
  --global \
  --enable-cdn \
  --connection-draining-timeout 300

# add the instance group to the backend
gcloud compute backend-services add-backend $INSTANCE_NAME-lb-backend \
  --instance-group $INSTANCE_NAME-instance-group \
  --instance-group-zone $ZONE \
  --balancing-mode UTILIZATION \
  --max-rate-per-instance 100 \
  --capacity-scaler 1.0 \
  --global

# create the url-map
gcloud compute url-maps create $INSTANCE_NAME-url-map \
  --default-service $INSTANCE_NAME-lb-backend

# create the http proxy
gcloud compute target-http-proxies create $INSTANCE_NAME-http-proxy \
  --url-map $INSTANCE_NAME-url-map

# create a global forwarding rule a.k.a. frontend
gcloud compute forwarding-rules create $INSTANCE_NAME-forwarding-rule \
  --global \
  --ports 80 \
  --target-http-proxy $INSTANCE_NAME-http-proxy