Create multiple EC2 instance and give dynamically name & instance type
🌟Count :
Count is Terraform meta-argument is used in resource block to specify that resource how many times run.count is a meta-argument defined by the Terraform language. It can be used with modules and with every resource type.
Meta-argument:
The terraform argument which is used in any resources are known as 'Meta-argument'.
Count.index:
It's special variable which define length of list of count. such as os[0] , os[1], os[2]......
In this work i have created below files for my code , mypsfile is created by "-out" keyword which store all setup code in binary format.
" # terraform.exe plan -out=mypsfile "
⚡Step-1:⚡
provider file for plugin and put credentials info .(aws provider plugin)
# notepad provider.tf
⚡Step-2:⚡
Here main.tf file for all code related to aws_instance Resource block.
Data Source for AMI: It fetches the latest Amazon Linux 2 AMI with a specific naming convention (al2023-ami-*-x86_64) and other filters.
EC2 Instance Resource: It defines an EC2 instance resource, using the AMI fetched in the previous step. It specifies the instance type, security group ID, and creates multiple instances using the count meta-argument.
Variables: "names": A list of names for instances, "instanceType": A list of instance types, "sec-grpID": Security Group ID.
Output: It outputs a message based on the value of the Give-true-false variable. If it's true, it outputs a welcome message; otherwise, it suggests trying again later.
Locals: It defines some local values, such as admin name, owner, salary, and current time.
# notepad main.tf
In terraform 'varible' we can't use terraform function, Because of this "locals" is used. (check main.tf file). Output block is required to run local value.
max(): max function is used to retrieve maximum value .
formatdate(): It's is terraform function which give format for date.
timestamp(): It's terraform function which run in real time and give real time.
⚡Step-3:⚡
Now, 1st use terraform init & then terraform apply command entire setup is launched, i give true value output is welcome show during apply command run. & current date and time show .
# terraform init
# terraform apply
❄️ Now check on AWS console :---
here all three instances is launched with given instance type as well as instance name .
For each instance bellow security group created by terraform:
I give security group id in "vpc_security_group_ids" argument , the security group is created on aws console manually and only security_group id i give in terraform main block.
