Hi Techies!

Good day!

We are going to see how to troubleshoot issues in terraform(Alternate Ansible) script which will create VPC in AWS.

In my script the file name is main.tf and we need to execute “terraform init, terraform validate, terraform apply” commands one by one.

terraform init:   It will initialize the directory, which will contains the terraform configuration file(in our scenario main.tf)

terraform validate: It will to check the syntax and consistency of your Terraform configuration files without accessing remote services

terraform plan: It will help to create an execution plan and preview the changes to your infrastructure.

terraform apply: It will execute the proposed actions in a Terraform plan.

In our scenario I’m getting error while applying it (terraform apply)

Error:

Error: creating EC2 Instance: operation error EC2: RunInstances, https response error StatusCode: 400, RequestID: 5eea2384-64e8-4a57-ba1a-2ac955c799f9, api error InvalidSubnetID.NotFound: The subnet ID 'aws_subnet.pubsubnet.id' does not exist
│
│ with aws_instance.pub_instance,
│ on main.tf line 157, in resource "aws_instance" "pub_instance":
│ 157: resource "aws_instance" "pub_instance" {
│
╵
╷
│ Error: creating EC2 Instance: operation error EC2: RunInstances, https response error StatusCode: 400, RequestID: 64d5c412-e7db-49ad-a7aa-49b4f9345d89, api error InvalidSubnetID.NotFound: The subnet ID 'aws_subnet.pvtsubnet.id' does not exist
│
│ with aws_instance.pvt_instance,
│ on main.tf line 172, in resource "aws_instance" "pvt_instance":
│ 172: resource "aws_instance" "pvt_instance" {

Code in my script:

 resource "aws_instance" "pub_instance" {
ami                                     = "ami-033fabdd332044f06"
instance_type                           = "t2.micro"
availability_zone                       = "us-east-2a"
associate_public_ip_address             = "true"
vpc_security_group_ids                  = [aws_security_group.PUBSG.id]
subnet_id                               = "aws_subnet.PUBSUB.id"
key_name                                = "Terraform_Srv"

  tags = {
  Name = "WEBSERVER"
 }

}

resource "aws_instance" "pvt_instance" {
ami                                     = "ami-033fabdd332044f06"
instance_type                           = "t2.micro"
availability_zone                       = "us-east-2b"
associate_public_ip_address             = "true"
vpc_security_group_ids                  = [aws_security_group.PVTSG.id]
subnet_id                               = "aws_subnet.PVTSUB.id"
key_name                                = "Terraform_Srv"

  tags = {
  Name = "APPSERVER"
 }

}

Solution:

In may script I have used double quotes (“”) to mention subnet id. In my case I have removed double quotes and it fixed the issue.

resource "aws_instance" "pub_instance" {
ami                                    = "ami-033fabdd332044f06"
instance_type                          = "t2.micro"
availability_zone                      = "us-east-2a"
associate_public_ip_address            = "true"
vpc_security_group_ids                 = [aws_security_group.PUBSG.id]
subnet_id                              = aws_subnet.PUBSUB.id
key_name                               = "Terraform_Srv"

tags = {
Name = "WEBSERVER"
}

}

resource "aws_instance" "pvt_instance" {
ami                                    = "ami-033fabdd332044f06"
instance_type                          = "t2.micro"
availability_zone                      = "us-east-2b"
associate_public_ip_address            = "true"
vpc_security_group_ids                 = [aws_security_group.PVTSG.id]
subnet_id                              = aws_subnet.PVTSUB.id
key_name                               = "Terraform_Srv"

tags = {
Name = "APPSERVER"
}

}

Now while executing “terraform apply” it created ec2-instance along with VPC successfully.

Result:

#terraform apply

aws_instance.pvt_instance: Creating...
aws_instance.pub_instance: Creating...
aws_route_table.PVTRT: Modifying... [id=rtb-05ab30d4598210e59]
aws_route_table.PVTRT: Modifications complete after 0s [id=rtb-05ab30d4598210e59]
aws_instance.pub_instance: Still creating... [10s elapsed]
aws_instance.pvt_instance: Still creating... [10s elapsed]
aws_instance.pvt_instance: Still creating... [20s elapsed]
aws_instance.pub_instance: Still creating... [20s elapsed]
aws_instance.pub_instance: Still creating... [30s elapsed]
aws_instance.pvt_instance: Still creating... [30s elapsed]
aws_instance.pvt_instance: Creation complete after 31s [id=i-096c28fbbaeff8a42]
aws_instance.pub_instance: Creation complete after 31s [id=i-0f745c3aeca6327aa]
Apply complete! Resources: 2 added, 1 changed, 0 destroyed.
[root@ip-172-31-7-226 terraform]#