resource "aws_vpc" "default" {
  cidr_block           = "10.0.0.0/16"
  enable_dns_hostnames = true

  tags {
    Name = "tf_test"
  }
}

resource "aws_subnet" "tf_test_subnet" {
  vpc_id                  = "${aws_vpc.default.id}"
  cidr_block              = "10.0.0.0/24"
  map_public_ip_on_launch = true

  tags {
    Name = "tf_test_subnet"
  }
}

resource "aws_internet_gateway" "gw" {
  vpc_id = "${aws_vpc.default.id}"

  tags {
    Name = "tf_test_ig"
  }
}

resource "aws_route_table" "r" {
  vpc_id = "${aws_vpc.default.id}"

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

  tags {
    Name = "aws_route_table"
  }
}

resource "aws_route_table_association" "a" {
  subnet_id      = "${aws_subnet.tf_test_subnet.id}"
  route_table_id = "${aws_route_table.r.id}"
}

# Our default security group to access
# the instances over SSH and HTTP
resource "aws_security_group" "default" {
  name        = "ec2_sg"
  description = "Used in the terraform"
  vpc_id      = "${aws_vpc.default.id}"

  # SSH access from anywhere
  ingress {
    from_port   = 22
    to_port     = 22
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  # HTTP access from elb_security_group only
  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    security_groups = ["${aws_security_group.elb.id}"]

  }

  # outbound internet access
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }
}

# Our elb security group to access
# the ELB over HTTP
resource "aws_security_group" "elb" {
  name        = "hello_elb_sg"
  description = "Used in the terraform"

  vpc_id = "${aws_vpc.default.id}"

  # HTTP access from anywhere
  ingress {
    from_port   = 80
    to_port     = 80
    protocol    = "tcp"
    cidr_blocks = ["0.0.0.0/0"]
  }

  # outbound internet access
  egress {
    from_port   = 0
    to_port     = 0
    protocol    = "-1"
    cidr_blocks = ["0.0.0.0/0"]
  }

  # ensure the VPC has an Internet gateway or this step will fail
  depends_on = ["aws_internet_gateway.gw"]
}