DevOps Classroom Series – 27/May/2020

Scenario: Create a EC2 instance in AWS

• Creating EC2 instance in AWS Watch Here
• For creating Ec2 instance. For any resource have a habit of knowing inputs and outputs before you create/provision in terraform
  • Inputs:
    1. Image ID
    2. Region
    3. Security Group
    4. Key Value Pair
    5. Subnet-id (VPC and AZ)
    6. instance type (size) => t2.micro
  • Outputs
    1. Id
    2. Ipaddress
    3. DNS Name
• Navigate to the docs page over here
• Created a new directory with provider.tf and computeresources.tf. In computeresoruces.tf

resource "aws_instance" "firstec2" {
    ami                             = "ami-003634241a8fcdec0"
    instance_type                   = "t2.micro"
    key_name                        = "ansible"
    vpc_security_group_ids          = [ "sg-003772772f5073f26" ]
    associate_public_ip_address     = true
    tags                            = {
        Name                        = "firstec2"
    }
}

• Provider.tf will have

provider "aws" {

}

• Now apply terraform to create ec2 instance which will work.
• This way is not suggestable as reusing this template on other aws accounts might not workout as this template is specific
• Lets try to make this template generic, by adding input variables
• Lets add a new file inputs.tf with the following content

variable "securitygroupid" {
    type    = string
}

variable "keyname" { 
    type    = string
}

• And the main.tf looks like

provider "aws" {
    
}

resource "aws_instance" "firstec2" {
    ami                             = "ami-003634241a8fcdec0"
    instance_type                   = "t2.micro"
    key_name                        = var.keyname
    vpc_security_group_ids          = [ var.securitygroupid ]
    associate_public_ip_address     = true
    tags                            = {
        Name                        = "firstec2"
    }
}