Terraform and Provisioner

Introduction

In this example, we will see how to deploy a VM and apply provisioner commands on it on the TFGrid.

Example

terraform {
  required_providers {
    grid = {
      source = "threefoldtech/grid"
    }
  }
}

provider "grid" {
}

locals {
  name = "myvm"
}

resource "grid_network" "net1" {
  nodes         = [1]
  ip_range      = "10.1.0.0/24"
  name          = local.name
  description   = "newer network"
  add_wg_access = true
}

resource "grid_deployment" "d1" {
  name         = local.name
  node         = 1
  network_name = grid_network.net1.name
  vms {
    name       = "vm1"
    flist      = "https://hub.grid.tf/tf-official-apps/grid3_ubuntu20.04-latest.flist"
    entrypoint = "/init.sh"
    cpu        = 2
    memory     = 1024
    env_vars = {
      SSH_KEY = file("~/.ssh/id_rsa.pub")
    }
    planetary = true
  }
  connection {
    type  = "ssh"
    user  = "root"
    agent = true
    host  = grid_deployment.d1.vms[0].planetary_ip
  }

  provisioner "remote-exec" {
    inline = [
      "echo 'Hello world!' > /root/readme.txt"
    ]
  }
}

Params docs

Requirements

• the machine should have ssh server running
• the machine should have scp installed

Connection Block

• defines how we will connect to the deployed machine

   connection {
    type     = "ssh"
    user     = "root"
    agent    = true
    host     = grid_deployment.d1.vms[0].planetary_ip
  }

type: defines the used service to connect to user: the connecting users agent: if used the provisoner will use the default key to connect to the remote machine host: the ip/host of the remote machine

Provisioner Block

• defines the actual provisioner behaviour

   provisioner "remote-exec" {
    inline = [
      "echo 'Hello world!' > /root/readme.txt"
    ]
  }

• remote-exec: the provisoner type we are willing to use can be remote, local or another type
• inline: This is a list of command strings. They are executed in the order they are provided. This cannot be provided with script or scripts.
• script: This is a path (relative or absolute) to a local script that will be copied to the remote resource and then executed. This cannot be provided with inline or scripts.
• scripts: This is a list of paths (relative or absolute) to local scripts that will be copied to the remote resource and then executed. They are executed in the order they are provided. This cannot be provided with inline or script.

More Info

A complete list of provisioner parameters can be found here.