main.tf

terraform {
  required_providers {
    aws = {
      source  = "hashicorp/aws"
      version = "~> 3.27"
    }
  }

  required_version = ">= 0.14.9"
}

provider "aws" {
  profile = "default"
  region  = "us-east-1"
}

resource "aws_vpc" "main" {
  cidr_block           = "10.0.0.0/16"
  instance_tenancy     = "default"
  enable_dns_hostnames = true
  enable_dns_support   = true
  tags = {
    Name = "main"
  }

}

resource "aws_internet_gateway" "gw" {
  vpc_id = aws_vpc.main.id

  tags = {
    Name = "main"
  }
}


variable "subnets_cidr" {
  type    = list(string)
  default = ["10.0.1.0/24", "10.0.2.0/24"]
}

variable "azs" {
  type    = list(any)
  default = ["us-east-1a", "us-east-1b"]
}

resource "aws_subnet" "public" {
  count                   = length(var.subnets_cidr)
  vpc_id                  = aws_vpc.main.id
  cidr_block              = element(var.subnets_cidr, count.index)
  availability_zone       = element(var.azs, count.index)
  map_public_ip_on_launch = true
  tags = {
    Name = "Subnet-${count.index + 1}"
  }
}

resource "aws_route_table" "public-rt" {
  vpc_id = aws_vpc.main.id

  route {
    cidr_block = "0.0.0.0/0"
    gateway_id = aws_internet_gateway.gw.id
  }

  tags = {
    Name = "public-rt"
  }
}

resource "aws_route_table_association" "a" {
  count          = length(var.subnets_cidr)
  subnet_id      = element(aws_subnet.public.*.id, count.index)
  route_table_id = aws_route_table.public-rt.id
}


resource "aws_db_subnet_group" "default" {
  name       = "main"
  subnet_ids = [aws_subnet.public[0].id, aws_subnet.public[1].id]

  tags = {
    Name = "My DB subnet group"
  }
}

resource "aws_security_group" "allow_postgres" {
  name        = "allow_postgres"
  description = "Allow Postgres Inbound traffic"
  vpc_id      = aws_vpc.main.id

  ingress {
    description = "allow postgres"
    from_port   = 5432
    to_port     = 5432
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  egress {
    from_port        = 0
    to_port          = 0
    protocol         = "-1"
    cidr_blocks      = ["0.0.0.0/0"]
    ipv6_cidr_blocks = ["::/0"]
  }

  tags = {
    Name = "allow postgres"
  }
}


resource "aws_db_instance" "db-test1" {
  allocated_storage      = 10
  identifier             = "postgres-test2"
  db_subnet_group_name   = aws_db_subnet_group.default.id
  engine                 = "postgres"
  engine_version         = "14"
  instance_class         = "db.t3.micro"
  username               = "postgres"
  password               = "postgres"
  vpc_security_group_ids = [aws_security_group.allow_tls.id]
  publicly_accessible    = true
  skip_final_snapshot    = true
}