minionize.sh.tpl

#!/bin/bash

MINION_NAME=${minion_name}
MASTER_HOST=${master_host}

# -----------------------------------------------------------------------------
# Set hostname matching minion name by updating /etc/hostname and /etc/hosts
# -----------------------------------------------------------------------------
hostnamectl set-hostname $MINION_NAME

cat > /etc/hosts <<END
127.0.0.1 localhost $MINION_NAME

# The following lines are desirable for IPv6 capable hosts
::1 ip6-localhost ip6-loopback
fe00::0 ip6-localnet
ff00::0 ip6-mcastprefix
ff02::1 ip6-allnodes
ff02::2 ip6-allrouters
ff02::3 ip6-allhosts
END


# -----------------------------------------------------------------------------
# Install and configure salt-minion
# -----------------------------------------------------------------------------

# This version is HEAD on the develop branch as of 2016.09.12
BS_URL="https://raw.githubusercontent.com/saltstack/salt-bootstrap/7206d7304362ea0f143db76cacada288a89abff9/bootstrap-salt.sh"
BS_EXPECTED_MD5="8532d4a20533a2210b0a893faa354bce"

curl -sL -o /tmp/bootstrap-salt.sh "$BS_URL"
BS_ACTUAL_MD5=$(md5sum /tmp/bootstrap-salt.sh | awk '{print $1}')
if [ "$BS_EXPECTED_MD5" -ne "$BS_ACTUAL_MD5" ];
then
	echo "MD5 signature mismatch, mayday!"
	touch /root/.salt-md5-mismatch
	exit 1
fi

BS_SALT_MASTER_ADDRESS=$MASTER_HOST bash /tmp/bootstrap-salt.sh

cat > /etc/salt/minion_id <<END
$MINION_NAME
END

cat > /etc/salt/minion <<END
master: $MASTER_HOST
hash_type: SHA256
END

service salt-minion restart

minions.tf

variable "minion-count" {
  type    = "string"
  default = 1
}

data "template_file" "minionize-data" {
  count    = "${var.minion-count}"
  template = "${file("minionize.sh.tpl")}"

  vars {
    minion_name   = "${format("minion%02d", count.index)}"
    master_host   = "saltmaster.example.com"
    bootstrap_key = "${aws_key_pair.minion-bootstrap.public_key}"
  }
}

resource "aws_instance" "minion" {
  count = "${var.minion-count}"

  ami   = "${var.base_ami}"
  subnet_id     = "${aws_subnet.my_infrastructure.id}"
  instance_type = "m4.large"
  vpc_security_group_ids = [
    # ...
  ]

  tags = {
    Name = "${format("minion%02d", count.index)}"
  }

  root_block_device {
    volume_type = "standard"
    volume_size = 100
  }

  user_data = "${element(data.template_file.minionize-data.*.rendered, count.index)}"
}