security_group.tf

#https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/default_security_group
resource "aws_default_security_group" "default" {
  vpc_id = aws_vpc.this.id
}

#https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/security_group
resource "aws_security_group" "rds" {
  name        = "${var.name}-rds-sg"
  description = "Security group for RDS in ${var.name}"
  vpc_id      = aws_vpc.this.id
  tags = {
    "Name" = "${var.name}-rds-sg"
  }
}
#https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/security_group_rule
resource "aws_security_group_rule" "ingress_rds_sg" {
  description       = "allow traffic to RDS"
  type              = "ingress"
  from_port         = 5432
  to_port           = 5432
  protocol          = "tcp"
  cidr_blocks       = [var.vpc_cidr]
  security_group_id = aws_security_group.rds.id
}
#https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/security_group_rule
resource "aws_security_group_rule" "egress_rds_sg" {
  description       = "allow traffic to reach outside the vpc"
  type              = "egress"
  from_port         = 0
  to_port           = 0
  protocol          = "-1"
  cidr_blocks       = [var.vpc_cidr]
  security_group_id = aws_security_group.rds.id
}