Introduction

It’s been over a year since I’ve had my blog up without any new content, I figured now would be a good time to post a quick update on a “new” Terraform provisioner for Chef Habitat.

With the recent changes HashiCorp has announced with built-in Terraform provisioners, there exists a need to build a self-contained plugin to deploy Chef Habitat to VM instances.

The terraform-proivisioner-habitat project aims to achieve that goal, while expanding support of the plugin to provision Chef Habitat to Windows, bringing it up-to-date with Habitat supervisor feature parity, and providing

Installation

The installation process is a bit cumbersome, since provisioners can’t be downloaded as a plugin module from the Terraform registry.

• Download a pre-built binary release from GitHub Releases page
• Make sure the filename matches: terraform-provisioner-habitat_v<version>
• Place the file in ~/.terraform.d/plugins/ directory

Example

In the example below, we are going to create 4 virtual machines–3 x for the supervisor ring, and 1 x linux host which will join the supervisor ring.

For a more comprehensive example, review the Terraform integration tests from the GitHub Repo.

Supervisor Ring VMs

Create a supervisor-ring.tf file that looks something like this:

//
// Linux Habitat Dedicated Supervisor Ring
//
resource "vsphere_virtual_machine" "supervisor-ring" {
  count = 3

  //
  // Generic VM settings
  //
  num_cpus                    = 4
  memory                      = 4096
  name                        = format("sup-ring-%s", count.index+1)
  resource_pool_id            = data.vsphere_resource_pool.pool.id
  datastore_id                = data.vsphere_datastore.datastores[count.index].id
  folder                      = var.vsphere.folder
  guest_id                    = data.vsphere_virtual_machine.linux-template.guest_id
  scsi_type                   = data.vsphere_virtual_machine.linux-template.scsi_type
  host_system_id              = data.vsphere_host.hosts[count.index].id

  //
  // Primary VM disk
  //
  disk {
    label            = "disk0"
    eagerly_scrub    = data.vsphere_virtual_machine.linux-template.disks.0.eagerly_scrub
    thin_provisioned = data.vsphere_virtual_machine.linux-template.disks.0.thin_provisioned
    size             = data.vsphere_virtual_machine.linux-template.disks.0.size
    unit_number      = 0
  }

  //
  // NICs
  //
  network_interface {
    network_id = "..."
  }
}

//
// Provision Habitat Supervisor Ring--note that in the supervisor ring case, this is a on a separate null_resource so
// we can obtain the IP addresses for each sup-ring instance, and then provision Habitat to it
//
resource "null_resource" "habitat-provisioner" {
  depends_on = [vsphere_virtual_machine.supervisor-ring]
  count      = length(vsphere_virtual_machine.supervisor-ring[*])

  triggers = {
    cluster_instance_ids = join(",", vsphere_virtual_machine.supervisor-ring[*].id)
    user_toml_contents   = sha256(template_file.supervisor-ring-effortless_user_toml[index.count].rendered)
  }

  provisioner "habitat" {
    license            = "accept-no-persist"
    version            = "latest"
    peers              = vsphere_virtual_machine.supervisor-ring[*].default_ip_address
    use_sudo           = true
    permanent_peer     = true
    ring_key           = "my-ring-key"
    ring_key_content   = file("my-ring-key.sym.key")
    ctl_secret         = "dead-beef"
    
    service {
      name      = "klm/effortless"
      strategy  = "at-once"
      user_toml = template_file.supervisor-ring-effortless_user_toml[index.count].rendered
      channel   = "stable"
    }

    connection {
      type        = "ssh"
      host        = vsphere_virtual_machine.supervisor-ring[index.count].default_ip_address
      user        = var.habitat.hab_ssh_username
      password    = var.habitat.hab_ssh_password
      private_key = file("~/.ssh/id_rsa.pem")
    }
  }
}

//
// User toml for klm/effortless (supervisor-ring)
//
data "template_file" "supervisor-ring-effortless_user_toml" {
  count = 3
  template = file("effortless/user.tmpl.toml")

  vars = {
    machine_name   = vsphere_virtual_machine.supervisor-ring[count.index].name
    machine_domain = "klmh.co"
  }
}

Linux VM

Create a linux.tf file that looks something like this:

resource "vsphere_virtual_machine" "linux" {
  //
  // Generic VM settings
  //
  num_cpus                    = 4
  memory                      = 4096
  name                        = "linux"
  resource_pool_id            = data.vsphere_resource_pool.pool.id
  datastore_id                = data.vsphere_datastore.datastores[0].id
  folder                      = var.vsphere.folder
  guest_id                    = data.vsphere_virtual_machine.linux-template.guest_id
  scsi_type                   = data.vsphere_virtual_machine.linux-template.scsi_type
  host_system_id              = data.vsphere_host.hosts[0].id

  //
  // Primary VM disk
  //
  disk {
    label            = "disk0"
    eagerly_scrub    = data.vsphere_virtual_machine.linux-template.disks.0.eagerly_scrub
    thin_provisioned = data.vsphere_virtual_machine.linux-template.disks.0.thin_provisioned
    size             = data.vsphere_virtual_machine.linux-template.disks.0.size
    unit_number      = 0
  }

  //
  // NICs
  //
  network_interface {
    network_id = "..."
  }

  //
  // Provision Habitat
  //
  provisioner "habitat" {
    license            = "accept-no-persist"
    version            = "latest"
    peers              = vsphere_virtual_machine.supervisor-ring[*].default_ip_address
    use_sudo           = true
    permanent_peer     = false
    ring_key           = "my-ring-key"
    ring_key_content   = file("my-ring-key.sym.key")
    ctl_secret         = "dead-beef"
    
    service {
      name      = "klm/effortless"
      strategy  = "at-once"
      user_toml = template_file.linux-effortless_user_toml.rendered
      channel   = "stable"
    }

    connection {
      type        = "ssh"
      host        = self.default_ip_address
      user        = var.habitat.hab_ssh_username
      password    = var.habitat.hab_ssh_password
      private_key = file("~/.ssh/id_rsa.pem")
    }
  }
}

//
// User toml for klm/effortless (linux)
//
data "template_file" "linux-effortless_user_toml" {
  count = 3
  template = file("effortless/user.tmpl.toml")

  vars = {
    machine_name   = vsphere_virtual_machine.linux.name
    machine_domain = "klmh.co"
  }
}

Additional information

For more information, review the README.md.