Terraform 0.12 (#20)

* Terraform 0.12

README.md

@@ -3,6 +3,10 @@
 * These files are part of my Udemy course about Terraform
 * Course URL: https://www.udemy.com/learn-devops-infrastructure-automation-with-terraform/?couponCode=TERRAFORM_GIT
 
+# Compatibility
+
+* This is the >=terraform-0.12 branch. For compatibility with older versions, use the terraform-0.11 branch.
+
 # Demo overview
 Demo Directory | Description
 ------------ | -------------

demo-1/instance.tf

@@ -1,4 +1,5 @@
 resource "aws_instance" "example" {
-  ami           = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
 }
+

demo-1/provider.tf

@@ -1,6 +1,6 @@
 provider "aws" {
-    access_key = "${var.AWS_ACCESS_KEY}"
-    secret_key = "${var.AWS_SECRET_KEY}"
-    region = "${var.AWS_REGION}"
+  access_key = var.AWS_ACCESS_KEY
+  secret_key = var.AWS_SECRET_KEY
+  region     = var.AWS_REGION
 }
 

demo-1/vars.tf

@@ -1,13 +1,19 @@
-variable "AWS_ACCESS_KEY" {}
-variable "AWS_SECRET_KEY" {}
+variable "AWS_ACCESS_KEY" {
+}
+
+variable "AWS_SECRET_KEY" {
+}
+
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-0d729a60"
   }
 }
+

demo-1/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-10/cloudinit.tf

@@ -1,29 +1,30 @@
 data "template_file" "init-script" {
-  template = "${file("scripts/init.cfg")}"
-  vars {
-    REGION = "${var.AWS_REGION}"
+  template = file("scripts/init.cfg")
+  vars = {
+    REGION = var.AWS_REGION
   }
 }
-data "template_file" "shell-script" {
-  template = "${file("scripts/volumes.sh")}"
-  vars {
-    DEVICE = "${var.INSTANCE_DEVICE_NAME}"
-  }
-}
-data "template_cloudinit_config" "cloudinit-example" {
 
+data "template_file" "shell-script" {
+  template = file("scripts/volumes.sh")
+  vars = {
+    DEVICE = var.INSTANCE_DEVICE_NAME
+  }
+}
+
+data "template_cloudinit_config" "cloudinit-example" {
   gzip          = false
   base64_encode = false
 
   part {
     filename     = "init.cfg"
     content_type = "text/cloud-config"
-    content      = "${data.template_file.init-script.rendered}"
+    content      = data.template_file.init-script.rendered
   }
 
   part {
     content_type = "text/x-shellscript"
-    content      = "${data.template_file.shell-script.rendered}"
+    content      = data.template_file.shell-script.rendered
   }
-
 }
+

demo-10/instance.tf

@@ -1,33 +1,32 @@
 resource "aws_instance" "example" {
-  ami           = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
 
   # the VPC subnet
-  subnet_id = "${aws_subnet.main-public-1.id}"
+  subnet_id = aws_subnet.main-public-1.id
 
   # the security group
-  vpc_security_group_ids = ["${aws_security_group.allow-ssh.id}"]
+  vpc_security_group_ids = [aws_security_group.allow-ssh.id]
 
   # the public SSH key
-  key_name = "${aws_key_pair.mykeypair.key_name}"
+  key_name = aws_key_pair.mykeypair.key_name
 
   # user data
-  user_data = "${data.template_cloudinit_config.cloudinit-example.rendered}"
-
+  user_data = data.template_cloudinit_config.cloudinit-example.rendered
 }
 
 resource "aws_ebs_volume" "ebs-volume-1" {
   availability_zone = "eu-west-1a"
   size              = 20
   type              = "gp2"
-    tags {
+  tags = {
     Name = "extra volume data"
   }
 }
 
 resource "aws_volume_attachment" "ebs-volume-1-attachment" {
-  device_name = "${var.INSTANCE_DEVICE_NAME}"
-  volume_id = "${aws_ebs_volume.ebs-volume-1.id}"
-  instance_id = "${aws_instance.example.id}"
+  device_name = var.INSTANCE_DEVICE_NAME
+  volume_id   = aws_ebs_volume.ebs-volume-1.id
+  instance_id = aws_instance.example.id
 }
 

demo-10/key.tf

@@ -1,4 +1,5 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
+

demo-10/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-10/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "allow-ssh" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
   egress {
@@ -15,7 +15,8 @@ resource "aws_security_group" "allow-ssh" {
     protocol    = "tcp"
     cidr_blocks = ["0.0.0.0/0"]
   }
-tags {
+  tags = {
     Name = "allow-ssh"
   }
 }
+

demo-10/vars.tf

@@ -1,20 +1,25 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
+
 variable "INSTANCE_DEVICE_NAME" {
   default = "/dev/xvdh"
 }
+

demo-10/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-10/vpc.tf

@@ -5,106 +5,113 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+

demo-11/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-11/route53.tf

@@ -1,22 +1,25 @@
 resource "aws_route53_zone" "newtech-academy" {
   name = "newtech.academy"
 }
+
 resource "aws_route53_record" "server1-record" {
-   zone_id = "${aws_route53_zone.newtech-academy.zone_id}"
+  zone_id = aws_route53_zone.newtech-academy.zone_id
   name    = "server1.newtech.academy"
   type    = "A"
   ttl     = "300"
   records = ["104.236.247.8"]
 }
+
 resource "aws_route53_record" "www-record" {
-   zone_id = "${aws_route53_zone.newtech-academy.zone_id}"
+  zone_id = aws_route53_zone.newtech-academy.zone_id
   name    = "www.newtech.academy"
   type    = "A"
   ttl     = "300"
   records = ["104.236.247.8"]
 }
+
 resource "aws_route53_record" "mail1-record" {
-   zone_id = "${aws_route53_zone.newtech-academy.zone_id}"
+  zone_id = aws_route53_zone.newtech-academy.zone_id
   name    = "newtech.academy"
   type    = "MX"
   ttl     = "300"
@@ -25,10 +28,11 @@ resource "aws_route53_record" "mail1-record" {
     "5 alt1.aspmx.l.google.com.",
     "5 alt2.aspmx.l.google.com.",
     "10 aspmx2.googlemail.com.",
-     "10 aspmx3.googlemail.com."
+    "10 aspmx3.googlemail.com.",
   ]
 }
 
 output "ns-servers" {
-   value = "${aws_route53_zone.newtech-academy.name_servers}"
+  value = aws_route53_zone.newtech-academy.name_servers
 }
+

demo-11/vars.tf

@@ -1,3 +1,4 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+

demo-11/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-12/instance.tf

@@ -1,14 +1,14 @@
 resource "aws_instance" "example" {
-  ami           = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
 
   # the VPC subnet
-  subnet_id = "${aws_subnet.main-public-1.id}"
+  subnet_id = aws_subnet.main-public-1.id
 
   # the security group
-  vpc_security_group_ids = ["${aws_security_group.example-instance.id}"]
+  vpc_security_group_ids = [aws_security_group.example-instance.id]
 
   # the public SSH key
-  key_name = "${aws_key_pair.mykeypair.key_name}"
-
+  key_name = aws_key_pair.mykeypair.key_name
 }
+

demo-12/key.tf

@@ -1,4 +1,5 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
+

demo-12/output.tf

@@ -1,6 +1,8 @@
 output "instance" {
-  value = "${aws_instance.example.public_ip}"
+  value = aws_instance.example.public_ip
 }
+
 output "rds" {
-  value = "${aws_db_instance.mariadb.endpoint}"
+  value = aws_db_instance.mariadb.endpoint
 }
+

demo-12/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-12/rds.tf

@@ -1,7 +1,7 @@
 resource "aws_db_subnet_group" "mariadb-subnet" {
   name        = "mariadb-subnet"
   description = "RDS subnet group"
-    subnet_ids = ["${aws_subnet.main-private-1.id}","${aws_subnet.main-private-2.id}"]
+  subnet_ids  = [aws_subnet.main-private-1.id, aws_subnet.main-private-2.id]
 }
 
 resource "aws_db_parameter_group" "mariadb-parameters" {
@@ -13,10 +13,8 @@ resource "aws_db_parameter_group" "mariadb-parameters" {
     name  = "max_allowed_packet"
     value = "16777216"
   }
-
 }
 
-
 resource "aws_db_instance" "mariadb" {
   allocated_storage       = 100 # 100 GB of storage, gives us more IOPS than a lower number
   engine                  = "mariadb"
@@ -25,16 +23,17 @@ resource "aws_db_instance" "mariadb" {
   identifier              = "mariadb"
   name                    = "mariadb"
   username                = "root"           # username
-  password             = "${var.RDS_PASSWORD}" # password
-  db_subnet_group_name = "${aws_db_subnet_group.mariadb-subnet.name}"
-  parameter_group_name = "${aws_db_parameter_group.mariadb-parameters.name}"
+  password                = var.RDS_PASSWORD # password
+  db_subnet_group_name    = aws_db_subnet_group.mariadb-subnet.name
+  parameter_group_name    = aws_db_parameter_group.mariadb-parameters.name
   multi_az                = "false" # set to true to have high availability: 2 instances synchronized with each other
-  vpc_security_group_ids = ["${aws_security_group.allow-mariadb.id}"]
+  vpc_security_group_ids  = [aws_security_group.allow-mariadb.id]
   storage_type            = "gp2"
   backup_retention_period = 30                                          # how long you’re going to keep your backups
-  availability_zone = "${aws_subnet.main-private-1.availability_zone}"   # prefered AZ
+  availability_zone       = aws_subnet.main-private-1.availability_zone # prefered AZ
   skip_final_snapshot     = true                                        # skip final snapshot when doing terraform destroy
-  tags {
+  tags = {
     Name = "mariadb-instance"
   }
 }
+

demo-12/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "example-instance" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
   egress {
@@ -15,20 +15,20 @@ resource "aws_security_group" "example-instance" {
     protocol    = "tcp"
     cidr_blocks = ["0.0.0.0/0"]
   }
-tags {
+  tags = {
     Name = "example-instance"
   }
 }
 
 resource "aws_security_group" "allow-mariadb" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-mariadb"
   description = "allow-mariadb"
   ingress {
     from_port       = 3306
     to_port         = 3306
     protocol        = "tcp"
-      security_groups = ["${aws_security_group.example-instance.id}"]              # allowing access from our example instance
+    security_groups = [aws_security_group.example-instance.id] # allowing access from our example instance
   }
   egress {
     from_port   = 0
@@ -37,7 +37,7 @@ resource "aws_security_group" "allow-mariadb" {
     cidr_blocks = ["0.0.0.0/0"]
     self        = true
   }
-  tags {
+  tags = {
     Name = "allow-mariadb"
   }
 }

demo-12/vars.tf

@@ -1,18 +1,24 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
-variable "RDS_PASSWORD" { }
+
+variable "RDS_PASSWORD" {
+}
+

demo-12/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-12/vpc.tf

@@ -5,106 +5,113 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+

demo-13/iam.tf

@@ -2,27 +2,32 @@
 resource "aws_iam_group" "administrators" {
   name = "administrators"
 }
+
 resource "aws_iam_policy_attachment" "administrators-attach" {
   name       = "administrators-attach"
-    groups = ["${aws_iam_group.administrators.name}"]
+  groups     = [aws_iam_group.administrators.name]
   policy_arn = "arn:aws:iam::aws:policy/AdministratorAccess"
 }
+
 # user
 resource "aws_iam_user" "admin1" {
   name = "admin1"
 }
+
 resource "aws_iam_user" "admin2" {
   name = "admin2"
 }
+
 resource "aws_iam_group_membership" "administrators-users" {
   name = "administrators-users"
   users = [
-        "${aws_iam_user.admin1.name}",
-        "${aws_iam_user.admin2.name}",
+    aws_iam_user.admin1.name,
+    aws_iam_user.admin2.name,
   ]
-    group = "${aws_iam_group.administrators.name}"
+  group = aws_iam_group.administrators.name
 }
 
 output "warning" {
   value = "WARNING: make sure you're not using the AdministratorAccess policy for other users/groups/roles. If this is the case, don't run terraform destroy, but manually unlink the created resources"
 }
+

demo-13/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-13/vars.tf

@@ -1,3 +1,4 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+

demo-13/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-14/iam.tf

@@ -15,16 +15,17 @@ resource "aws_iam_role" "s3-mybucket-role" {
   ]
 }
 EOF
+
 }
 
 resource "aws_iam_instance_profile" "s3-mybucket-role-instanceprofile" {
   name = "s3-mybucket-role"
-    role = "${aws_iam_role.s3-mybucket-role.name}"
+  role = aws_iam_role.s3-mybucket-role.name
 }
 
 resource "aws_iam_role_policy" "s3-mybucket-role-policy" {
   name = "s3-mybucket-role-policy"
-    role = "${aws_iam_role.s3-mybucket-role.id}"
+  role = aws_iam_role.s3-mybucket-role.id
   policy = <<EOF
 {
     "Version": "2012-10-17",
@@ -42,5 +43,6 @@ resource "aws_iam_role_policy" "s3-mybucket-role-policy" {
     ]
 }
 EOF
+
 }
 

demo-14/instance.tf

@@ -1,17 +1,17 @@
 resource "aws_instance" "example" {
-  ami           = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
 
   # the VPC subnet
-  subnet_id = "${aws_subnet.main-public-1.id}"
+  subnet_id = aws_subnet.main-public-1.id
 
   # the security group
-  vpc_security_group_ids = ["${aws_security_group.example-instance.id}"]
+  vpc_security_group_ids = [aws_security_group.example-instance.id]
 
   # the public SSH key
-  key_name = "${aws_key_pair.mykeypair.key_name}"
+  key_name = aws_key_pair.mykeypair.key_name
 
   # role:
-  iam_instance_profile = "${aws_iam_instance_profile.s3-mybucket-role-instanceprofile.name}"
-
+  iam_instance_profile = aws_iam_instance_profile.s3-mybucket-role-instanceprofile.name
 }
+

demo-14/key.tf

@@ -1,4 +1,5 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
+

demo-14/output.tf

@@ -1,3 +1,4 @@
 output "instance" {
-  value = "${aws_instance.example.public_ip}"
+  value = aws_instance.example.public_ip
 }
+

demo-14/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-14/s3.tf

@@ -2,7 +2,8 @@ resource "aws_s3_bucket" "b" {
   bucket = "mybucket-c29df1"
   acl    = "private"
 
-    tags {
+  tags = {
     Name = "mybucket-c29df1"
   }
 }
+

demo-14/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "example-instance" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
   egress {
@@ -15,7 +15,7 @@ resource "aws_security_group" "example-instance" {
     protocol    = "tcp"
     cidr_blocks = ["0.0.0.0/0"]
   }
-tags {
+  tags = {
     Name = "example-instance"
   }
 }

demo-14/vars.tf

@@ -1,17 +1,21 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
+

demo-14/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-14/vpc.tf

@@ -5,106 +5,113 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+

demo-15/autoscaling.tf

@@ -1,15 +1,15 @@
 resource "aws_launch_configuration" "example-launchconfig" {
   name_prefix     = "example-launchconfig"
-  image_id             = "${lookup(var.AMIS, var.AWS_REGION)}"
+  image_id        = var.AMIS[var.AWS_REGION]
   instance_type   = "t2.micro"
-  key_name             = "${aws_key_pair.mykeypair.key_name}"
-  security_groups      = ["${aws_security_group.allow-ssh.id}"]
+  key_name        = aws_key_pair.mykeypair.key_name
+  security_groups = [aws_security_group.allow-ssh.id]
 }
 
 resource "aws_autoscaling_group" "example-autoscaling" {
   name                      = "example-autoscaling"
-  vpc_zone_identifier  = ["${aws_subnet.main-public-1.id}", "${aws_subnet.main-public-2.id}"]
-  launch_configuration = "${aws_launch_configuration.example-launchconfig.name}"
+  vpc_zone_identifier       = [aws_subnet.main-public-1.id, aws_subnet.main-public-2.id]
+  launch_configuration      = aws_launch_configuration.example-launchconfig.name
   min_size                  = 1
   max_size                  = 2
   health_check_grace_period = 300

demo-15/autoscalingpolicy.tf

@@ -2,7 +2,7 @@
 
 resource "aws_autoscaling_policy" "example-cpu-policy" {
   name                   = "example-cpu-policy"
-  autoscaling_group_name = "${aws_autoscaling_group.example-autoscaling.name}"
+  autoscaling_group_name = aws_autoscaling_group.example-autoscaling.name
   adjustment_type        = "ChangeInCapacity"
   scaling_adjustment     = "1"
   cooldown               = "300"
@@ -21,17 +21,17 @@ resource "aws_cloudwatch_metric_alarm" "example-cpu-alarm" {
   threshold           = "30"
 
   dimensions = {
-    "AutoScalingGroupName" = "${aws_autoscaling_group.example-autoscaling.name}"
+    "AutoScalingGroupName" = aws_autoscaling_group.example-autoscaling.name
   }
 
   actions_enabled = true
-  alarm_actions   = ["${aws_autoscaling_policy.example-cpu-policy.arn}"]
+  alarm_actions   = [aws_autoscaling_policy.example-cpu-policy.arn]
 }
 
 # scale down alarm
 resource "aws_autoscaling_policy" "example-cpu-policy-scaledown" {
   name                   = "example-cpu-policy-scaledown"
-  autoscaling_group_name = "${aws_autoscaling_group.example-autoscaling.name}"
+  autoscaling_group_name = aws_autoscaling_group.example-autoscaling.name
   adjustment_type        = "ChangeInCapacity"
   scaling_adjustment     = "-1"
   cooldown               = "300"
@@ -50,9 +50,10 @@ resource "aws_cloudwatch_metric_alarm" "example-cpu-alarm-scaledown" {
   threshold           = "5"
 
   dimensions = {
-    "AutoScalingGroupName" = "${aws_autoscaling_group.example-autoscaling.name}"
+    "AutoScalingGroupName" = aws_autoscaling_group.example-autoscaling.name
   }
 
   actions_enabled = true
-  alarm_actions   = ["${aws_autoscaling_policy.example-cpu-policy-scaledown.arn}"]
+  alarm_actions   = [aws_autoscaling_policy.example-cpu-policy-scaledown.arn]
 }
+

demo-15/key.tf

@@ -1,7 +1,8 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
   lifecycle {
-    ignore_changes = ["public_key"]
+    ignore_changes = [public_key]
   }
 }
+

demo-15/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-15/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "allow-ssh" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
   egress {
@@ -15,7 +15,8 @@ resource "aws_security_group" "allow-ssh" {
     protocol    = "tcp"
     cidr_blocks = ["0.0.0.0/0"]
   }
-tags {
+  tags = {
     Name = "allow-ssh"
   }
 }
+

demo-15/sns.tf

@@ -1,5 +1,4 @@
 # Uncomment if you want to have autoscaling notifications
-
 #resource "aws_sns_topic" "example-sns" {
 #  name         = "sg-sns"
 #  display_name = "example ASG SNS topic"

demo-15/vars.tf

@@ -1,17 +1,21 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
+

demo-15/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-15/vpc.tf

@@ -5,106 +5,113 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+

demo-16/autoscaling.tf

@@ -1,22 +1,24 @@
 resource "aws_launch_configuration" "example-launchconfig" {
   name_prefix     = "example-launchconfig"
-  image_id             = "${lookup(var.AMIS, var.AWS_REGION)}"
+  image_id        = var.AMIS[var.AWS_REGION]
   instance_type   = "t2.micro"
-  key_name             = "${aws_key_pair.mykeypair.key_name}"
-  security_groups      = ["${aws_security_group.myinstance.id}"]
+  key_name        = aws_key_pair.mykeypair.key_name
+  security_groups = [aws_security_group.myinstance.id]
   user_data       = "#!/bin/bash\napt-get update\napt-get -y install nginx\nMYIP=`ifconfig | grep 'addr:10' | awk '{ print $2 }' | cut -d ':' -f2`\necho 'this is: '$MYIP > /var/www/html/index.html"
-  lifecycle              { create_before_destroy = true }
+  lifecycle {
+    create_before_destroy = true
+  }
 }
 
 resource "aws_autoscaling_group" "example-autoscaling" {
   name                      = "example-autoscaling"
-  vpc_zone_identifier  = ["${aws_subnet.main-public-1.id}", "${aws_subnet.main-public-2.id}"]
-  launch_configuration = "${aws_launch_configuration.example-launchconfig.name}"
+  vpc_zone_identifier       = [aws_subnet.main-public-1.id, aws_subnet.main-public-2.id]
+  launch_configuration      = aws_launch_configuration.example-launchconfig.name
   min_size                  = 2
   max_size                  = 2
   health_check_grace_period = 300
   health_check_type         = "ELB"
-  load_balancers = ["${aws_elb.my-elb.name}"]
+  load_balancers            = [aws_elb.my-elb.name]
   force_delete              = true
 
   tag {

demo-16/elb.tf

@@ -1,7 +1,7 @@
 resource "aws_elb" "my-elb" {
   name            = "my-elb"
-  subnets = ["${aws_subnet.main-public-1.id}", "${aws_subnet.main-public-2.id}"]
-  security_groups = ["${aws_security_group.elb-securitygroup.id}"]
+  subnets         = [aws_subnet.main-public-1.id, aws_subnet.main-public-2.id]
+  security_groups = [aws_security_group.elb-securitygroup.id]
   listener {
     instance_port     = 80
     instance_protocol = "http"
@@ -19,7 +19,7 @@ resource "aws_elb" "my-elb" {
   cross_zone_load_balancing   = true
   connection_draining         = true
   connection_draining_timeout = 400
-  tags {
+  tags = {
     Name = "my-elb"
   }
 }

demo-16/key.tf

@@ -1,7 +1,8 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
   lifecycle {
-    ignore_changes = ["public_key"]
+    ignore_changes = [public_key]
   }
 }
+

demo-16/output.tf

@@ -1,3 +1,4 @@
 output "ELB" {
-	value = "${aws_elb.my-elb.dns_name}"
+  value = aws_elb.my-elb.dns_name
 }
+

demo-16/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-16/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "myinstance" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "myinstance"
   description = "security group for my instance"
   egress {
@@ -20,15 +20,16 @@ resource "aws_security_group" "myinstance" {
     from_port       = 80
     to_port         = 80
     protocol        = "tcp"
-      security_groups = ["${aws_security_group.elb-securitygroup.id}"]
+    security_groups = [aws_security_group.elb-securitygroup.id]
   }
 
-  tags {
+  tags = {
     Name = "myinstance"
   }
 }
+
 resource "aws_security_group" "elb-securitygroup" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "elb"
   description = "security group for load balancer"
   egress {
@@ -44,7 +45,8 @@ resource "aws_security_group" "elb-securitygroup" {
     protocol    = "tcp"
     cidr_blocks = ["0.0.0.0/0"]
   }
-  tags {
+  tags = {
     Name = "elb"
   }
 }
+

demo-16/vars.tf

@@ -1,17 +1,21 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
+

demo-16/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-16/vpc.tf

@@ -5,106 +5,113 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+

demo-17/elasticbeanstalk.tf

@@ -5,12 +5,12 @@ resource "aws_elastic_beanstalk_application" "app" {
 
 resource "aws_elastic_beanstalk_environment" "app-prod" {
   name                = "app-prod"
-  application = "${aws_elastic_beanstalk_application.app.name}"
+  application         = aws_elastic_beanstalk_application.app.name
   solution_stack_name = "64bit Amazon Linux 2016.09 v2.3.0 running PHP 7.0"
   setting {
     namespace = "aws:ec2:vpc"
     name      = "VPCId"
-    value     = "${aws_vpc.main.id}"
+    value     = aws_vpc.main.id
   }
   setting {
     namespace = "aws:ec2:vpc"
@@ -25,17 +25,17 @@ resource "aws_elastic_beanstalk_environment" "app-prod" {
   setting {
     namespace = "aws:autoscaling:launchconfiguration"
     name      = "IamInstanceProfile"
-    value = "${aws_iam_instance_profile.app-ec2-role.name}"
+    value     = aws_iam_instance_profile.app-ec2-role.name
   }
   setting {
     namespace = "aws:autoscaling:launchconfiguration"
     name      = "SecurityGroups"
-    value = "${aws_security_group.app-prod.id}"
+    value     = aws_security_group.app-prod.id
   }
   setting {
     namespace = "aws:autoscaling:launchconfiguration"
     name      = "EC2KeyName"
-    value = "${aws_key_pair.mykeypair.id}"
+    value     = aws_key_pair.mykeypair.id
   }
   setting {
     namespace = "aws:autoscaling:launchconfiguration"
@@ -45,7 +45,7 @@ resource "aws_elastic_beanstalk_environment" "app-prod" {
   setting {
     namespace = "aws:elasticbeanstalk:environment"
     name      = "ServiceRole"
-    value = "${aws_iam_role.elasticbeanstalk-service-role.name}"
+    value     = aws_iam_role.elasticbeanstalk-service-role.name
   }
   setting {
     namespace = "aws:ec2:vpc"
@@ -90,23 +90,22 @@ resource "aws_elastic_beanstalk_environment" "app-prod" {
   setting {
     namespace = "aws:elasticbeanstalk:application:environment"
     name      = "RDS_USERNAME"
-    value = "${aws_db_instance.mariadb.username}"
+    value     = aws_db_instance.mariadb.username
   }
   setting {
     namespace = "aws:elasticbeanstalk:application:environment"
     name      = "RDS_PASSWORD"
-    value = "${aws_db_instance.mariadb.password}"
+    value     = aws_db_instance.mariadb.password
   }
   setting {
     namespace = "aws:elasticbeanstalk:application:environment"
     name      = "RDS_DATABASE"
-    value = "mydb"
-    value = "${aws_db_instance.mariadb.name}"
+    value     = aws_db_instance.mariadb.name
   }
   setting {
     namespace = "aws:elasticbeanstalk:application:environment"
     name      = "RDS_HOSTNAME"
-    value = "${aws_db_instance.mariadb.endpoint}"
+    value     = aws_db_instance.mariadb.endpoint
   }
 }
 

demo-17/iam.tf

@@ -16,10 +16,12 @@ resource "aws_iam_role" "app-ec2-role" {
   ]
 }
 EOF
+
 }
+
 resource "aws_iam_instance_profile" "app-ec2-role" {
   name = "app-ec2-role"
-    role = "${aws_iam_role.app-ec2-role.name}"
+  role = aws_iam_role.app-ec2-role.name
 }
 
 # service
@@ -40,26 +42,31 @@ resource "aws_iam_role" "elasticbeanstalk-service-role" {
   ]
 }
 EOF
+
 }
 
 # policies
 resource "aws_iam_policy_attachment" "app-attach1" {
-    name = "app-attach1"
-    roles = ["${aws_iam_role.app-ec2-role.name}"]
-    policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkWebTier"
+name       = "app-attach1"
+roles      = [aws_iam_role.app-ec2-role.name]
+policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkWebTier"
 }
+
 resource "aws_iam_policy_attachment" "app-attach2" {
-    name = "app-attach2"
-    roles = ["${aws_iam_role.app-ec2-role.name}"]
-    policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkMulticontainerDocker"
+name       = "app-attach2"
+roles      = [aws_iam_role.app-ec2-role.name]
+policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkMulticontainerDocker"
 }
+
 resource "aws_iam_policy_attachment" "app-attach3" {
-    name = "app-attach3"
-    roles = ["${aws_iam_role.app-ec2-role.name}"]
-    policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkWorkerTier"
+name       = "app-attach3"
+roles      = [aws_iam_role.app-ec2-role.name]
+policy_arn = "arn:aws:iam::aws:policy/AWSElasticBeanstalkWorkerTier"
 }
+
 resource "aws_iam_policy_attachment" "app-attach4" {
-    name = "app-attach4"
-    roles = ["${aws_iam_role.elasticbeanstalk-service-role.name}"]
-    policy_arn = "arn:aws:iam::aws:policy/service-role/AWSElasticBeanstalkEnhancedHealth"
+name       = "app-attach4"
+roles      = [aws_iam_role.elasticbeanstalk-service-role.name]
+policy_arn = "arn:aws:iam::aws:policy/service-role/AWSElasticBeanstalkEnhancedHealth"
 }
+

demo-17/key.tf

@@ -1,7 +1,8 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
   lifecycle {
-    ignore_changes = ["public_key"]
+    ignore_changes = [public_key]
   }
 }
+

demo-17/output.tf

@@ -1,3 +1,4 @@
 output "eb" {
-	value = "${aws_elastic_beanstalk_environment.app-prod.cname}"
+  value = aws_elastic_beanstalk_environment.app-prod.cname
 }
+

demo-17/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-    region = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-17/rds.tf

@@ -1,7 +1,7 @@
 resource "aws_db_subnet_group" "mariadb-subnet" {
   name        = "mariadb-subnet"
   description = "RDS subnet group"
-    subnet_ids = ["${aws_subnet.main-private-1.id}","${aws_subnet.main-private-2.id}"]
+  subnet_ids  = [aws_subnet.main-private-1.id, aws_subnet.main-private-2.id]
 }
 
 resource "aws_db_parameter_group" "mariadb-parameters" {
@@ -13,10 +13,8 @@ resource "aws_db_parameter_group" "mariadb-parameters" {
     name  = "max_allowed_packet"
     value = "16777216"
   }
-
 }
 
-
 resource "aws_db_instance" "mariadb" {
   allocated_storage         = 100 # 100 GB of storage, gives us more IOPS than a lower number
   engine                    = "mariadb"
@@ -25,16 +23,17 @@ resource "aws_db_instance" "mariadb" {
   identifier                = "mariadb"
   name                      = "mydatabase"     # database name
   username                  = "root"           # username
-  password             = "${var.RDS_PASSWORD}" # password
-  db_subnet_group_name = "${aws_db_subnet_group.mariadb-subnet.name}"
-  parameter_group_name = "${aws_db_parameter_group.mariadb-parameters.name}"
+  password                  = var.RDS_PASSWORD # password
+  db_subnet_group_name      = aws_db_subnet_group.mariadb-subnet.name
+  parameter_group_name      = aws_db_parameter_group.mariadb-parameters.name
   multi_az                  = "false" # set to true to have high availability: 2 instances synchronized with each other
-  vpc_security_group_ids = ["${aws_security_group.allow-mariadb.id}"]
+  vpc_security_group_ids    = [aws_security_group.allow-mariadb.id]
   storage_type              = "gp2"
   backup_retention_period   = 30                                          # how long you’re going to keep your backups
-  availability_zone = "${aws_subnet.main-private-1.availability_zone}"   # prefered AZ
+  availability_zone         = aws_subnet.main-private-1.availability_zone # prefered AZ
   final_snapshot_identifier = "mariadb-final-snapshot"                    # final snapshot when executing terraform destroy
-  tags {
+  tags = {
     Name = "mariadb-instance"
   }
 }
+

demo-17/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "app-prod" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "application - production"
   description = "security group for my app"
   egress {
@@ -16,20 +16,20 @@ resource "aws_security_group" "app-prod" {
     cidr_blocks = ["0.0.0.0/0"]
   }
 
-
-  tags {
+  tags = {
     Name = "myinstance"
   }
 }
+
 resource "aws_security_group" "allow-mariadb" {
-  vpc_id = "${aws_vpc.main.id}"
+  vpc_id      = aws_vpc.main.id
   name        = "allow-mariadb"
   description = "allow-mariadb"
   ingress {
     from_port       = 3306
     to_port         = 3306
     protocol        = "tcp"
-      security_groups = ["${aws_security_group.app-prod.id}"]              # allowing access from our example instance
+    security_groups = [aws_security_group.app-prod.id] # allowing access from our example instance
   }
   egress {
     from_port   = 0
@@ -38,7 +38,8 @@ resource "aws_security_group" "allow-mariadb" {
     cidr_blocks = ["0.0.0.0/0"]
     self        = true
   }
-  tags {
+  tags = {
     Name = "allow-mariadb"
   }
 }
+

demo-17/vars.tf

@@ -1,10 +1,15 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
-variable "RDS_PASSWORD" {}
+
+variable "RDS_PASSWORD" {
+}
+

demo-17/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-17/vpc.tf

@@ -5,139 +5,152 @@ resource "aws_vpc" "main" {
   enable_dns_support   = "true"
   enable_dns_hostnames = "true"
   enable_classiclink   = "false"
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
-
 # Subnets
 resource "aws_subnet" "main-public-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.1.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
+
 resource "aws_subnet" "main-public-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.2.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-public-2"
   }
 }
+
 resource "aws_subnet" "main-public-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.3.0/24"
   map_public_ip_on_launch = "true"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-public-3"
   }
 }
+
 resource "aws_subnet" "main-private-1" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.4.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1a"
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 resource "aws_subnet" "main-private-2" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.5.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1b"
 
-    tags {
+  tags = {
     Name = "main-private-2"
   }
 }
+
 resource "aws_subnet" "main-private-3" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id                  = aws_vpc.main.id
   cidr_block              = "10.0.6.0/24"
   map_public_ip_on_launch = "false"
   availability_zone       = "eu-west-1c"
 
-    tags {
+  tags = {
     Name = "main-private-3"
   }
 }
 
 # Internet GW
 resource "aws_internet_gateway" "main-gw" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
 
-    tags {
+  tags = {
     Name = "main"
   }
 }
 
 # route tables
 resource "aws_route_table" "main-public" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block = "0.0.0.0/0"
-        gateway_id = "${aws_internet_gateway.main-gw.id}"
+    gateway_id = aws_internet_gateway.main-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-public-1"
   }
 }
 
 # route associations public
 resource "aws_route_table_association" "main-public-1-a" {
-    subnet_id = "${aws_subnet.main-public-1.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-1.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-2-a" {
-    subnet_id = "${aws_subnet.main-public-2.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-2.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table_association" "main-public-3-a" {
-    subnet_id = "${aws_subnet.main-public-3.id}"
-    route_table_id = "${aws_route_table.main-public.id}"
+  subnet_id      = aws_subnet.main-public-3.id
+  route_table_id = aws_route_table.main-public.id
 }
+
 resource "aws_route_table" "main-private" {
-    vpc_id = "${aws_vpc.main.id}"
+  vpc_id = aws_vpc.main.id
   route {
     cidr_block     = "0.0.0.0/0"
-        nat_gateway_id = "${aws_nat_gateway.nat-gw.id}"
+    nat_gateway_id = aws_nat_gateway.nat-gw.id
   }
 
-    tags {
+  tags = {
     Name = "main-private-1"
   }
 }
+
 # route associations private
 resource "aws_route_table_association" "main-private-1-a" {
-    subnet_id = "${aws_subnet.main-private-1.id}"
-    route_table_id = "${aws_route_table.main-private.id}"
+  subnet_id      = aws_subnet.main-private-1.id
+  route_table_id = aws_route_table.main-private.id
 }
+
 resource "aws_route_table_association" "main-private-2-a" {
-    subnet_id = "${aws_subnet.main-private-2.id}"
-    route_table_id = "${aws_route_table.main-private.id}"
+  subnet_id      = aws_subnet.main-private-2.id
+  route_table_id = aws_route_table.main-private.id
 }
+
 resource "aws_route_table_association" "main-private-3-a" {
-    subnet_id = "${aws_subnet.main-private-3.id}"
-    route_table_id = "${aws_route_table.main-private.id}"
+  subnet_id      = aws_subnet.main-private-3.id
+  route_table_id = aws_route_table.main-private.id
 }
+
 # nat gw
 resource "aws_eip" "nat" {
   vpc = true
 }
+
 resource "aws_nat_gateway" "nat-gw" {
-  allocation_id = "${aws_eip.nat.id}"
-  subnet_id = "${aws_subnet.main-public-1.id}"
-  depends_on = ["aws_internet_gateway.main-gw"]
+  allocation_id = aws_eip.nat.id
+  subnet_id     = aws_subnet.main-public-1.id
+  depends_on    = [aws_internet_gateway.main-gw]
 }
+

demo-18/instance.tf

@@ -15,15 +15,16 @@ data "aws_ami" "ubuntu" {
 }
 
 resource "aws_instance" "example" {
-  ami           = "${data.aws_ami.ubuntu.id}"
+  ami           = data.aws_ami.ubuntu.id
   instance_type = "t2.micro"
 
   # the VPC subnet
-  subnet_id = "${var.ENV == "prod" ? module.vpc-prod.public_subnets[0] : module.vpc-dev.public_subnets[0] }"
+  subnet_id = var.ENV == "prod" ? module.vpc-prod.public_subnets[0] : module.vpc-dev.public_subnets[0]
 
   # the security group
-  vpc_security_group_ids = ["${var.ENV == "prod" ? aws_security_group.allow-ssh-prod.id : aws_security_group.allow-ssh-dev.id }"]
+  vpc_security_group_ids = [var.ENV == "prod" ? aws_security_group.allow-ssh-prod.id : aws_security_group.allow-ssh-dev.id]
 
   # the public SSH key
-  key_name = "${aws_key_pair.mykeypair.key_name}"
+  key_name = aws_key_pair.mykeypair.key_name
 }
+

demo-18/key.tf

@@ -1,4 +1,5 @@
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
+

demo-18/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-  region  = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-18/securitygroup.tf

@@ -1,5 +1,5 @@
 resource "aws_security_group" "allow-ssh-prod" {
-  vpc_id      = "${module.vpc-prod.vpc_id}"
+  vpc_id      = module.vpc-prod.vpc_id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
 
@@ -17,13 +17,13 @@ resource "aws_security_group" "allow-ssh-prod" {
     cidr_blocks = ["0.0.0.0/0"]
   }
 
-  tags {
+  tags = {
     Name = "allow-ssh"
   }
 }
 
 resource "aws_security_group" "allow-ssh-dev" {
-  vpc_id      = "${module.vpc-dev.vpc_id}"
+  vpc_id      = module.vpc-dev.vpc_id
   name        = "allow-ssh"
   description = "security group that allows ssh and all egress traffic"
 
@@ -41,7 +41,8 @@ resource "aws_security_group" "allow-ssh-dev" {
     cidr_blocks = ["0.0.0.0/0"]
   }
 
-  tags {
+  tags = {
     Name = "allow-ssh"
   }
 }
+

demo-18/vars.tf

@@ -13,3 +13,4 @@ variable "PATH_TO_PUBLIC_KEY" {
 variable "ENV" {
   default = "prod"
 }
+

demo-18/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-18/vpc.tf

@@ -1,5 +1,6 @@
 module "vpc-prod" {
   source  = "terraform-aws-modules/vpc/aws"
+  version = "2.5.0"
 
   name = "vpc-prod"
   cidr = "10.0.0.0/16"
@@ -19,6 +20,7 @@ module "vpc-prod" {
 
 module "vpc-dev" {
   source  = "terraform-aws-modules/vpc/aws"
+  version = "2.5.0"
 
   name = "vpc-dev"
   cidr = "10.0.0.0/16"
@@ -35,3 +37,4 @@ module "vpc-dev" {
     Environment = "dev"
   }
 }
+

demo-18b/dev/dev.tf

@@ -1,12 +1,13 @@
 module "main-vpc" {
   source     = "../modules/vpc"
   ENV        = "dev"
-  AWS_REGION = "${var.AWS_REGION}"
+  AWS_REGION = var.AWS_REGION
 }
 
 module "instances" {
   source         = "../modules/instances"
   ENV            = "dev"
-  VPC_ID = "${module.main-vpc.vpc_id}"
-  PUBLIC_SUBNETS = ["${module.main-vpc.public_subnets}"]
+  VPC_ID         = module.main-vpc.vpc_id
+  PUBLIC_SUBNETS = module.main-vpc.public_subnets
 }
+

demo-18b/dev/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-  region  = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-18b/dev/vars.tf

@@ -1,3 +1,4 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+

demo-18b/dev/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-18b/modules/instances/instance.tf

@@ -1,14 +1,16 @@
-variable "ENV" {}
+variable "ENV" {
+}
 
 variable "INSTANCE_TYPE" {
   default = "t2.micro"
 }
 
 variable "PUBLIC_SUBNETS" {
-  type = "list"
+  type = list
 }
 
-variable "VPC_ID" {}
+variable "VPC_ID" {
+}
 
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
@@ -31,26 +33,26 @@ data "aws_ami" "ubuntu" {
 }
 
 resource "aws_instance" "instance" {
-  ami           = "${data.aws_ami.ubuntu.id}"
-  instance_type = "${var.INSTANCE_TYPE}"
+  ami           = data.aws_ami.ubuntu.id
+  instance_type = var.INSTANCE_TYPE
 
   # the VPC subnet
-  subnet_id = "${var.PUBLIC_SUBNETS[0]}"
+  subnet_id = element(var.PUBLIC_SUBNETS, 0)
 
   # the security group
-  vpc_security_group_ids = ["${aws_security_group.allow-ssh.id}"]
+  vpc_security_group_ids = [aws_security_group.allow-ssh.id]
 
   # the public SSH key
-  key_name = "${aws_key_pair.mykeypair.key_name}"
+  key_name = aws_key_pair.mykeypair.key_name
 
-  tags {
+  tags = {
     Name         = "instance-${var.ENV}"
-    Environmnent = "${var.ENV}"
+    Environmnent = var.ENV
   }
 }
 
 resource "aws_security_group" "allow-ssh" {
-  vpc_id      = "${var.VPC_ID}"
+  vpc_id      = var.VPC_ID
   name        = "allow-ssh-${var.ENV}"
   description = "security group that allows ssh and all egress traffic"
 
@@ -68,13 +70,14 @@ resource "aws_security_group" "allow-ssh" {
     cidr_blocks = ["0.0.0.0/0"]
   }
 
-  tags {
+  tags = {
     Name         = "allow-ssh"
-    Environmnent = "${var.ENV}"
+    Environmnent = var.ENV
   }
 }
 
 resource "aws_key_pair" "mykeypair" {
   key_name   = "mykeypair-${var.ENV}"
-  public_key = "${file("${path.root}/${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file("${path.root}/${var.PATH_TO_PUBLIC_KEY}")
 }
+

demo-18b/modules/instances/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-18b/modules/vpc/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-18b/modules/vpc/vpc.tf

@@ -1,5 +1,8 @@
-variable "ENV" {}
-variable "AWS_REGION" {}
+variable "ENV" {
+}
+
+variable "AWS_REGION" {
+}
 
 module "main-vpc" {
   source = "terraform-aws-modules/vpc/aws"
@@ -16,21 +19,22 @@ module "main-vpc" {
 
   tags = {
     Terraform   = "true"
-    Environment = "${var.ENV}"
+    Environment = var.ENV
   }
 }
 
 output "vpc_id" {
   description = "The ID of the VPC"
-  value       = "${module.main-vpc.vpc_id}"
+  value       = module.main-vpc.vpc_id
 }
 
 output "private_subnets" {
   description = "List of IDs of private subnets"
-  value       = ["${module.main-vpc.private_subnets}"]
+  value       = module.main-vpc.private_subnets
 }
 
 output "public_subnets" {
   description = "List of IDs of public subnets"
-  value       = ["${module.main-vpc.public_subnets}"]
+  value       = module.main-vpc.public_subnets
 }
+

demo-18b/prod/prod.tf

@@ -1,12 +1,13 @@
 module "main-vpc" {
   source     = "../modules/vpc"
   ENV        = "prod"
-  AWS_REGION = "${var.AWS_REGION}"
+  AWS_REGION = var.AWS_REGION
 }
 
 module "instances" {
   source         = "../modules/instances"
   ENV            = "prod"
-  VPC_ID = "${module.main-vpc.vpc_id}"
-  PUBLIC_SUBNETS = ["${module.main-vpc.public_subnets}"]
+  VPC_ID         = module.main-vpc.vpc_id
+  PUBLIC_SUBNETS = module.main-vpc.public_subnets
 }
+

demo-18b/prod/provider.tf

@@ -1,3 +1,4 @@
 provider "aws" {
-  region  = "${var.AWS_REGION}"
+  region = var.AWS_REGION
 }
+

demo-18b/prod/vars.tf

@@ -1,3 +1,4 @@
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+

demo-18b/prod/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-2/instance.tf

@@ -1,12 +1,12 @@
 resource "aws_key_pair" "mykey" {
   key_name   = "mykey"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
 
 resource "aws_instance" "example" {
-  ami = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
-  key_name = "${aws_key_pair.mykey.key_name}"
+  key_name      = aws_key_pair.mykey.key_name
 
   provisioner "file" {
     source      = "script.sh"
@@ -15,12 +15,14 @@ resource "aws_instance" "example" {
   provisioner "remote-exec" {
     inline = [
       "chmod +x /tmp/script.sh",
-      "sudo /tmp/script.sh"
+      "sudo /tmp/script.sh",
     ]
   }
   connection {
-    host = "${self.public_ip}"
-    user = "${var.INSTANCE_USERNAME}"
-    private_key = "${file("${var.PATH_TO_PRIVATE_KEY}")}"
+    host        = coalesce(self.public_ip, self.private_ip)
+    type        = "ssh"
+    user        = var.INSTANCE_USERNAME
+    private_key = file(var.PATH_TO_PRIVATE_KEY)
   }
 }
+

demo-2/provider.tf

@@ -1,6 +1,6 @@
 provider "aws" {
-    access_key = "${var.AWS_ACCESS_KEY}"
-    secret_key = "${var.AWS_SECRET_KEY}"
-    region = "${var.AWS_REGION}"
+  access_key = var.AWS_ACCESS_KEY
+  secret_key = var.AWS_SECRET_KEY
+  region     = var.AWS_REGION
 }
 

demo-2/vars.tf

@@ -1,10 +1,15 @@
-variable "AWS_ACCESS_KEY" {}
-variable "AWS_SECRET_KEY" {}
+variable "AWS_ACCESS_KEY" {
+}
+
+variable "AWS_SECRET_KEY" {
+}
+
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
@@ -15,9 +20,12 @@ variable "AMIS" {
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "INSTANCE_USERNAME" {
   default = "ubuntu"
 }
+

demo-2/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-2b/provider.tf

@@ -1,6 +1,6 @@
 provider "aws" {
-    access_key = "${var.AWS_ACCESS_KEY}"
-    secret_key = "${var.AWS_SECRET_KEY}"
-    region = "${var.AWS_REGION}"
+  access_key = var.AWS_ACCESS_KEY
+  secret_key = var.AWS_SECRET_KEY
+  region     = var.AWS_REGION
 }
 

demo-2b/vars.tf

@@ -1,10 +1,15 @@
-variable "AWS_ACCESS_KEY" {}
-variable "AWS_SECRET_KEY" {}
+variable "AWS_ACCESS_KEY" {
+}
+
+variable "AWS_SECRET_KEY" {
+}
+
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "WIN_AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-30540427"
     us-west-2 = "ami-9f5efbff"
@@ -15,10 +20,15 @@ variable "WIN_AMIS" {
 variable "PATH_TO_PRIVATE_KEY" {
   default = "mykey"
 }
+
 variable "PATH_TO_PUBLIC_KEY" {
   default = "mykey.pub"
 }
+
 variable "INSTANCE_USERNAME" {
   default = "Terraform"
 }
-variable "INSTANCE_PASSWORD" { }
+
+variable "INSTANCE_PASSWORD" {
+}
+

demo-2b/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-2b/windows-instance.tf

@@ -1,12 +1,12 @@
 resource "aws_key_pair" "mykey" {
   key_name   = "mykey"
-  public_key = "${file("${var.PATH_TO_PUBLIC_KEY}")}"
+  public_key = file(var.PATH_TO_PUBLIC_KEY)
 }
 
 resource "aws_instance" "win-example" {
-  ami = "${lookup(var.WIN_AMIS, var.AWS_REGION)}"
+  ami           = var.WIN_AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
-  key_name = "${aws_key_pair.mykey.key_name}"
+  key_name      = aws_key_pair.mykey.key_name
   user_data     = <<EOF
 <powershell>
 net user ${var.INSTANCE_USERNAME} '${var.INSTANCE_PASSWORD}' /add /y
@@ -27,6 +27,7 @@ net start winrm
 </powershell>
 EOF
 
+
   provisioner "file" {
     source = "test.txt"
     destination = "C:/test.txt"
@@ -35,7 +36,8 @@ EOF
     host = coalesce(self.public_ip, self.private_ip)
     type = "winrm"
     timeout = "10m"
-    user = "${var.INSTANCE_USERNAME}"
-    password = "${var.INSTANCE_PASSWORD}"
+    user = var.INSTANCE_USERNAME
+    password = var.INSTANCE_PASSWORD
   }
 }
+

demo-3/instance.tf

@@ -1,10 +1,12 @@
 resource "aws_instance" "example" {
-  ami = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
   provisioner "local-exec" {
     command = "echo ${aws_instance.example.private_ip} >> private_ips.txt"
   }
 }
+
 output "ip" {
-    value = "${aws_instance.example.public_ip}"
+  value = aws_instance.example.public_ip
 }
+

demo-3/provider.tf

@@ -1,6 +1,6 @@
 provider "aws" {
-    access_key = "${var.AWS_ACCESS_KEY}"
-    secret_key = "${var.AWS_SECRET_KEY}"
-    region = "${var.AWS_REGION}"
+  access_key = var.AWS_ACCESS_KEY
+  secret_key = var.AWS_SECRET_KEY
+  region     = var.AWS_REGION
 }
 

demo-3/vars.tf

@@ -1,13 +1,19 @@
-variable "AWS_ACCESS_KEY" {}
-variable "AWS_SECRET_KEY" {}
+variable "AWS_ACCESS_KEY" {
+}
+
+variable "AWS_SECRET_KEY" {
+}
+
 variable "AWS_REGION" {
   default = "eu-west-1"
 }
+
 variable "AMIS" {
-  type = "map"
+  type = map(string)
   default = {
     us-east-1 = "ami-13be557e"
     us-west-2 = "ami-06b94666"
     eu-west-1 = "ami-844e0bf7"
   }
 }
+

demo-3/versions.tf

@@ -0,0 +1,4 @@
+
+terraform {
+  required_version = ">= 0.12"
+}

demo-4/instance.tf

@@ -1,10 +1,12 @@
 resource "aws_instance" "example" {
-  ami = "${lookup(var.AMIS, var.AWS_REGION)}"
+  ami           = var.AMIS[var.AWS_REGION]
   instance_type = "t2.micro"
   provisioner "local-exec" {
     command = "echo ${aws_instance.example.private_ip} >> private_ips.txt"
   }
 }
+
 output "ip" {
-    value = "${aws_instance.example.public_ip}"
+  value = aws_instance.example.public_ip
 }
+