main.tf

# Create data nodes, equally distrubting them across specified subnets / AVs
resource "aws_instance" "data_node" {
  ami                    = var.ami
  instance_type          = var.instance_type
  subnet_id              = var.subnet_id
  key_name               = var.key_name
  user_data              = var.user_data == "" ? file("${path.module}/init/data-nodes.sh") : var.user_data
  ebs_optimized          = true
  vpc_security_group_ids = var.security_group
  count                  = var.data_instances
}

resource "aws_ebs_volume" "data" {
  size              = var.data_disk_size
  encrypted         = true
  type              = "io1"
  iops              = var.data_disk_iops
  availability_zone = var.availabity_zone
  count             = var.data_instances
}

resource "aws_volume_attachment" "data_attachment" {
  device_name  = var.data_disk_device_name
  volume_id    = aws_ebs_volume.data.*.id[count.index]
  instance_id  = aws_instance.data_node.*.id[count.index]
  count        = var.data_instances
  force_detach = true
}

# Creates all meta nodes in the first / same subnet, this avoids splits if one AV goes offline.
# Data nodes function fine without access to meta-nodes between shard creation.
 resource "aws_instance" "meta_node" {
     ami                         = var.ami
     instance_type               = "t2.medium"
     subnet_id                   = var.subnet_id
     key_name                    = var.key_name
     user_data                   = var.user_data == "" ? file("${path.module}/init/meta-nodes.sh") : var.user_data
     vpc_security_group_ids      = var.security_group
     count                       = var.meta_instances
 }

 resource "aws_ebs_volume" "meta" {
     size              = "100"
     encrypted         = true
     type              = "io1"
     iops              = var.data_disk_iops
     availability_zone = var.availabity_zone
     count             = var.meta_instances
 }

 resource "aws_volume_attachment" "meta" {
     device_name = var.meta_disk_device_name
     volume_id   = aws_ebs_volume.meta.*.id[count.index]
     instance_id = aws_instance.meta_node.*.id[count.index]
     count       = var.meta_instances
     force_detach = true
 }

resource "aws_route53_record" "meta_node" {
     zone_id = var.zone_id
     name    = "${var.name}-meta${format("%02d", count.index + 1)}"
     type    = "A"
     ttl     = "120"
     records = ["${element(aws_instance.meta_node.*.private_ip, count.index)}"]
     count   = var.meta_instances
 }

 resource "aws_route53_record" "data_node" {
     zone_id = var.zone_id
     name    = "${var.name}-data${format("%02d", count.index + 1)}"
     type    = "A"
     ttl     = "120"
     records = ["${element(aws_instance.data_node.*.private_ip, count.index)}"]
     count   = var.data_instances
 }


# Setup inter-node cluster communications.
 resource "aws_security_group" "influxdb_cluster" {
     name        = "${var.name}_cluster"
     description = "Rules required for an Influx Enterprise Cluster"
     vpc_id      = "${var.vpc_id}"
 }

 resource "aws_security_group_rule" "cluster_comms" {
   type              = "ingress"
   from_port         = 8088
   to_port           = 8091
   protocol          = "tcp"
   cidr_blocks       = "${formatlist("%s/32", concat(aws_instance.meta_node.*.private_ip, aws_instance.data_node.*.private_ip))}"
   security_group_id = "${aws_security_group.influxdb_cluster.id}"
 }

resource "aws_security_group_rule" "outbound" {
   type              = "egress"
   to_port           = 0
   protocol          = "-1"
   from_port         = 0
   cidr_blocks       = ["0.0.0.0/0"]
   security_group_id = "${aws_security_group.influxdb_cluster.id}"
 }

resource "aws_security_group" "data_node" {
     description = "Security group for influx data node ingress"
     vpc_id      = var.vpc_id
     
     ingress {
         from_port   = "8086"
         to_port     = "8086"
         protocol    = "tcp"
         cidr_blocks = ["0.0.0.0/0"]
     }
 }