Terraform with AWS

Maine Goal : Primary goal of this post is to explain core concept of terraform
Terraform : Infrastructure as Code Tool

Services : Basic AWS Services to demonstrate terraform concept

• Virtual Machine ( EC2 )
• Firewall ( Security Groups )
• AWS Users ( IAM Users )
• IP Address ( Elastic IP )

Basics of Firewall

Ports

• ports acts as a endpoint of communication to identify a given application or process on an linux operating system
• to know what ports are opened on a system we use netstat -ntlp

Firewall

• it's network security system that monitors and controls incoming and outgoing network traffic based on predetermined security rules
• for AWS we call it as security group
• Create Security group using terraform

resource "aws_security_group" "allow_tls" {
  name = "allow_tls"
  description = "Managed from Terraform | Allow TLS inbout traffic and all outbound traffic"
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "allow_tls"
  }
}

• Block of code to add inboud or outboud rules to terraform

// Ingress : inbound rules
// Egress : Outbound rules
resource "aws_vpc_security_group_ingress_rule" "allow_tls_ipv4" {
  security_group_id = aws_security_group.allow_tls.id
  cidr_ipv4 = aws_vpc.main.cidr_block
  from_port = 80
  ip_protocol = "tcp"
  to_port = 80
}

resource "aws_vpc_security_group_egress_rule" "allow_all_traffic_ipv4" {
  security_group_id = aws_security_group.allow_tls.id
  cidr_ipv4 = "0.0.0.0/0"
  ip_protocol = "-1" # semantically equivalent to all ports
}