The market network is built: four subnets, the public and private route tables, and the internet gateway on public. The web server's script is in ~/web.sh.

1. Keep the VPC's id in VPC and public-a's id in SUBNET:

   sh

   copy

   SUBNET=$(aws ec2 describe-subnets --filters Name=tag:Name,Values=public-a --query "Subnets[0].SubnetId" --output text)

2. Make public-a hand out public IPs.

3. Create a security group web in the VPC that lets in TCP 80 from anywhere, keeping its id in SG.

4. Put today's Amazon Linux 2023 image id in AMI, as in Chapter 3.

5. Launch a t3.micro named web in public-a with that group and ~/web.sh as user data.

6. Point SUBNET at private-a instead:

   sh

   copy

   SUBNET=$(aws ec2 describe-subnets --filters Name=tag:Name,Values=private-a --query "Subnets[0].SubnetId" --output text)

7. Launch a t3.micro named app there, with the same group and no user data.

8. Wait a minute, then curl web on its public IP.