GCP Classroom notes 24/Aug/2024

Cloud DNS

• How DNS Works
  
• DNS records Refer Here
• Google has DNS as a service offered by Cloud DNS, Cloud DNS supports two types of Zones
  • Public Zone:
    • These are accessed from the internet
  • Private Zone:
    • This is accesible within private networks (VPC) and can be used in Hybrid environments
• Using Cloud Domains we can register a Domain
  
• DNS Zones let you manage DNS Records (bought in Cloud DNS or even external)
• Lets create a private zone in a vpc
  
  
• Lets add necessary firewall rules in vpc to allow ssh and http
• Lets create couple of compute engine instances vm-web-1 and vm-web-2
• Add A name records to match private ip addresses
• Now ping from vm-web-2 to vm.web-2.<your domain>
• Private Zone Records can also be forwarded to on-prem DNS
• In DNS we need to look into routing policies which we will after the concept of compute

Command Line Activities

• Lets try to create a vpc with 3 subnets
  • web: 192.168.0.0/16 in delhi
  • app: 192.168.1.0/16 in delhi
  • db: 192.168.2.0/16 in delhi
• Lets try creating the firewall rules
  • which allow http i.e. TCP port 80 and 443 for all vm instances with tag web
  • which allow ssh i.e. TCP port 22 for all vm instances with tag linux
  • which allow rdp i.e. TCP port 3389 for all vm instances with tag windows
• Tips:
  • use –help or use reference Refer Here for figuring out commands
• Attempt 1: Try from your workstation

gcloud compute networks create my-vpc `
    --subnet-mode=custom `
    --bgp-routing-mode=regional


gcloud compute networks subnets create web `
    --network=my-vpc `
    --range='10.0.0.0/24' `
    --region='asia-south1'

gcloud compute networks subnets create app `
    --network=my-vpc `
    --range='10.0.1.0/24' `
    --region='asia-south1'

gcloud compute networks subnets create db `
    --network=my-vpc `
    --range='10.0.2.0/24' `
    --region='asia-south1'

gcloud compute firewall-rules create only-http `
    --network=my-vpc `
    --allow=tcp:80 `
    --direction=IN `
    --source-ranges='0.0.0.0/0' `
    --target-tags='web'

gcloud compute firewall-rules create only-ssh `
    --network=my-vpc `
    --allow=tcp:22 `
    --direction=IN `
    --source-ranges='0.0.0.0/0' `
    --target-tags='linux'

gcloud compute firewall-rules create only-rdp `
    --network=my-vpc `
    --allow=tcp:3389 `
    --direction=IN `
    --source-ranges='0.0.0.0/0' `
    --target-tags='windows'

#!/bin/bash
gcloud compute networks create my-vpc \
    --subnet-mode=custom \
    --bgp-routing-mode=regional


gcloud compute networks subnets create web \
    --network=my-vpc \
    --range='10.0.0.0/24' \
    --region='asia-south1'

gcloud compute networks subnets create app \
    --network=my-vpc \
    --range='10.0.1.0/24' \
    --region='asia-south1'

gcloud compute networks subnets create db \
    --network=my-vpc \
    --range='10.0.2.0/24' \
    --region='asia-south1'


gcloud compute firewall-rules create only-http \
    --network=my-vpc \
    --allow=tcp:80 \
    --direction=IN \
    --source-ranges='0.0.0.0/0' \
    --target-tags='web'

gcloud compute firewall-rules create only-ssh \
    --network=my-vpc \
    --allow=tcp:22 \
    --direction=IN \
    --source-ranges='0.0.0.0/0' \
    --target-tags='linux'

gcloud compute firewall-rules create only-rdp \
    --network=my-vpc \
    --allow=tcp:3389 \
    --direction=IN \
    --source-ranges='0.0.0.0/0' \
    --target-tags='windows'

• Attempt 2- A linux vm on gcp: In this case lets create a service account with compute network admin permissions and attach it to the gcp instance and execute the same commands
  . Todo