by XDK
18. September 2019 22:27
Explanation:
The user data is not executed due to the leading whitespaces in the following format
resource "aws_instance" "Terraform-Demo" {
ami = "${lookup(var.RegionToAmazonAMI, var.Region)}"
instance_type = "t2.micro"
key_name = "myaccountkey"
vpc_security_group_ids = ["${aws_security_group.webserver-sg-2.id}"]
user_data = <<EOF
#cloud-boothook
#! /bin/bash
sudo apt update
sudo apt install -y apache2
IP_ADDR=$(curl http://169.254.169.254/latest/meta-data/public-ipv4)
sudo chmod 777 /var/www/html
sudo echo "Terraform instance 2 with IP IP_ADDR" > /var/www/html/index.html
sudo echo "Terraform instance 2 with IP IP_ADDR -- OK" > /var/www/html/health.html
EOF
provisioner "local-exec" {
command = "echo ${aws_instance.Terraform-Demo.public_ip} > testP.txt"
}
tags = {
Name = "TerraformDemo"
}
}
Solution:
Either add hyphen in <<-EOF to trim the leading whitespaces or remove the whitespaces manually
by XDK
18. September 2019 22:09
Explanation:
EC2 instances launched in the subnet using Terraform or Cloudformation is missing public IPv4 address
Solution:
Add the following argument/property
CloudFormation:
MapPublicIpOnLaunch - Indicates whether instances launched in this subnet receive a public IPv4 address.
PubSubnetZoneA:
Type: 'AWS::EC2::Subnet'
Properties:
AvailabilityZone:
Fn::Select:
- '0'
- Fn::GetAZs:
Ref: 'AWS::Region'
CidrBlock: '10.0.10.0/24'
MapPublicIpOnLaunch: 'True'
VpcId:
Ref: 'VPC'
Tags:
- Key: 'Name'
Value:
'Fn::Join': [ ':', [ 'Public', 'Zone A', !Ref 'AWS::StackName' ] ]
Terraform:
map_public_ip_on_launch - (Optional) Specify true to indicate that instances launched into the subnet should be assigned a public IP address. Default is false.
resource "aws_subnet" "public-subnet-a" {
vpc_id = "${aws_vpc.vpc.id}"
map_public_ip_on_launch = true
cidr_block = "10.0.10.0/24"
availability_zone = "${data.aws_availability_zones.available.names[0]}"
tags = {
Name = "public-subnet-a:${var.labname}"
}
}
by XDK
18. September 2019 21:45
Exception:
Error: Reference to undeclared resource
on base.tf line 65, in resource "aws_subnet" "public-subnet-a":
65: availability_zone = "${data.aws_availability_zones.available.names[0]}"
A data resource "aws_availability_zones" "available" has not been declared in
the root module.
Explanation:
The exception occurred while assigning the availability zone for a region in the terraform template.
resource "aws_subnet" "public-subnet-a" {
vpc_id = "${aws_vpc.vpc.id}"
map_public_ip_on_launch = true
cidr_block = "10.0.10.0/24"
availability_zone = "${data.aws_availability_zones.available.names[0]}"
tags = {
Name = "public-subnet-a:${var.labname}"
}
}
Solution:
Add data module to get the availability zones for a region
data "aws_availability_zones" "available" {}
resource "aws_subnet" "public-subnet-a" {
vpc_id = "${aws_vpc.vpc.id}"
map_public_ip_on_launch = true
cidr_block = "10.0.10.0/24"
availability_zone = "${data.aws_availability_zones.available.names[0]}"
tags = {
Name = "public-subnet-a:${var.labname}"
}
}
Subscribe