Workshops Classroomnotes 21/Dec/2022

Automation using AWS CLI contd..

Activity 9: Create an ec2 instance

• For creating ec2 instance we have following needs
  • AMI id: They differ from region to region for the same OS (ubuntu 22.04)
  • Network
    • VPC (Region): AWS CLI by default uses default vpc to launch ec2 instance.
    • Subnet id: For choosing specific AZ.
    • Security Group: Solved as part of activity 8
  • Key-Pair:
    • Use the current machines id_rsa.pub (i.e. import)
    • Create a new key pair and store it some where in your system.
  • Size:
    • EC2: this can be a parameter
    • EBS: this can be a parameter
• Solution:
  • Lets try to figure how to get ami id
    bash
aws ec2 describe-images --filters "Name=owner-id,Values=099720109477" "Name=name,Values=ubuntu/images/hvm-ssd/ubuntu-jammy-22.04-amd64-server-20221201" --query "Images[0].ImageId" --region us-west-2 --output text
  • Exercise: Try to find AMI id of Redhat Linux 9 which works for all regions
  • Hint: use Name and owner id for fetching images uniquely
  • Solution:
    aws ec2 describe-images --filters "Name=name,Values=RHEL-9.1.0_HVM-20221101-x86_64-2-Hourly2-GP2" "Name=owner-id,Values=309956199498" --query "Images[0].ImageId" --output text
  • Refer Here for the script written so far.
• Get the default vpc id:

aws ec2 describe-vpcs --query "Vpcs[?IsDefault].VpcId | [0]" --output text --region "${region}

• Get the subnet id of a specific az in subnet

aws ec2 describe-subnets --filters "Name=availability-zone, Values=${az}" "Name=vpc-id, Values=${vpc_id}" --query "Subnets[].SubnetId | [0]" --output text

• Get the security group id with name openall

sg_id=$(aws ec2 describe-security-groups --filters "Name=vpc-id,Values=${vpc_id}" --group-names "${group_name}" --query "SecurityGroups[].GroupId | [0]" --output text --region "${region}")
echo "Found security group in Vpc: ${vpc_id} with id ${sg_id} with name ${group_name}"

• Import the id_rsa.pub as key pair into your aws region.
• Lets create an ec2 instance in the specified region , in specified vpc/subnet with security group and key pair with instance size, disk size as parameter
• Refer Here for the script for creating.