cloud engineer
If you have to download a file from the Internet on a Windows server, can certainly use the browser. But if the browser is rendering the file instead of downloading them, you may have to use the curl command which is already pre-installed on most Windows servers. Just open the command line. Here’s the the curl command to download a file.
curl.exe --output index.txt --url https://website.domain/index.txt |
curl.exe --output index.txt --url https://website.domain/index.txt
Here’s how to setup a Network Load Balancer in GCP.
Setup your instances.
# Instance 1 gcloud compute instances create www1 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www1</h1></body></html>' | tee /var/www/html/index.html EOF" # Instance 2 gcloud compute instances create www2 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www2</h1></body></html>' | tee /var/www/html/index.html EOF" # Instance 3 gcloud compute instances create www3 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www3</h1></body></html>' | tee /var/www/html/index.html EOF" |
# Instance 1 gcloud compute instances create www1 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www1</h1></body></html>' | tee /var/www/html/index.html EOF" # Instance 2 gcloud compute instances create www2 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www2</h1></body></html>' | tee /var/www/html/index.html EOF" # Instance 3 gcloud compute instances create www3 \ --image-family debian-9 \ --image-project debian-cloud \ --zone us-central1-b \ --tags network-lb-tag \ --metadata startup-script="#! /bin/bash sudo apt-get update sudo apt-get install apache2 -y sudo service apache2 restart echo '<!doctype html><html><body><h1>www3</h1></body></html>' | tee /var/www/html/index.html EOF"
Create a firewall to allow external traffic to reach port 80.
gcloud compute firewall-rules create www-firewall-network-lb \
--target-tags network-lb-tag --allow tcp:80 |
gcloud compute firewall-rules create www-firewall-network-lb \ --target-tags network-lb-tag --allow tcp:80
Configure your network load balancer.
# Create an external IP address. gcloud compute addresses create network-lb-ip-1 \ --region us-central1 # Add a legacy HTTP health check. gcloud compute http-health-checks create basic-check # Add a target pool. gcloud compute target-pools add-instances www-pool \ --instances www1,www2,www3 \ --instances-zone us-central1-b # Add a forwarding rule. gcloud compute forwarding-rules create www-rule \ --region us-central1 \ --ports 80 \ --address network-lb-ip-1 \ --target-pool www-pool # Lookup external IP address. gcloud compute forwarding-rules describe www-rule \ --region us-central1 |
# Create an external IP address. gcloud compute addresses create network-lb-ip-1 \ --region us-central1 # Add a legacy HTTP health check. gcloud compute http-health-checks create basic-check # Add a target pool. gcloud compute target-pools add-instances www-pool \ --instances www1,www2,www3 \ --instances-zone us-central1-b # Add a forwarding rule. gcloud compute forwarding-rules create www-rule \ --region us-central1 \ --ports 80 \ --address network-lb-ip-1 \ --target-pool www-pool # Lookup external IP address. gcloud compute forwarding-rules describe www-rule \ --region us-central1
Finally, use the curl command to send traffic to the NLB external IP address.
while true; do curl -m1 [IP_ADDRESS]; done |
while true; do curl -m1 [IP_ADDRESS]; done
You can use the curl command to test if your load balancer is working as expected. The curl command will alternately and randomly access several instances in your load balancer. If you have 3 instances behind your load balancer, it will be cycled across all 3. The -m1 command means max time is set to 1 second.
while true; do curl -m1 [IP_ADDRESS]; done |
while true; do curl -m1 [IP_ADDRESS]; done