Terraform Provisioning

• Provisioning in Terraform is majorly used to do Configuration Management
• Terraform supports many provisioners, some of them are
  • remote-exec
  • local-exec
  • Chef
• For Ansible based CM use remote-exec to install ansible and execute ansible-playbook with localhost in inventory
• To use provisioners, you should also use connection
• Provisioners are written in terraform resources

resource '<resource-type>' '<resource-name>' {


    connection {
        ...
    }

    provisioner 'p-type' {

    }
}

• Lets create a ec2 machine and install git & apache
• First create ec2 machine

resource "aws_instance" "apache" {
    ami = "ami-04590e7389a6e577c"
    instance_type = "t2.micro"
    key_name = "packer"
    security_groups = ["sshonly"]
}

• Now lets add the connection section for terraform to connect to ec2 machine

resource "aws_instance" "apache" {
    ami = "ami-04590e7389a6e577c"
    instance_type = "t2.micro"
    key_name = "packer"
    security_groups = ["sshonly"]

    connection {
        type = "ssh"
        user = "ec2-user"
        host = "${aws_instance.apache.public_ip}"
        private_key = "${file("./packer.pem")}"
    }

  
}      

• Now lets provision using remote-exec to install git & apache

resource "aws_instance" "apache" {
    ami = "ami-04590e7389a6e577c"
    instance_type = "t2.micro"
    key_name = "packer"
    security_groups = ["sshonly"]

    connection {
        type = "ssh"
        user = "ec2-user"
        host = "${aws_instance.apache.public_ip}"
        private_key = "${file("./packer.pem")}"
    }

    provisioner "remote-exec" {
        inline = ["sudo yum install git -y", "sudo yum install httpd -y"]
    }

  
}

Backends

• To use Azurerm Backend refer here

• To use Aws Backend Refer Here

Exercise

• Write a terraform template to create two vms (ec2 or azure vms) and install tomcat in one vm and mongo db (any database) in other vm