Terraforming the clouds

Terraform is an infrastructure configuration manager by HashiCorp (Vagrant) like CloudFormation or Heat, supporting
various infrastructure providers including Amazon, VirtuaBox, …

Terraform reads *.tf and creates an execution plan containing all resources:

– instances
– volumes
– networks
– ..

You can check an example configuration here on github:

Unfortunately, it uses a custom but readable format instead of yaml.

# Create a 75GB volume on openstack
resource "openstack_blockstorage_volume_v1" "master-docker-vol" {
  name = "mastervol"
  size = 75
}

# Create a nova vm with the given colume attached
resource "openstack_compute_instance_v2" "machine" {
  name = "test"
  region = "${var.openstack_region}"
  image_id = "${var.master_image_id}"
  flavor_name = "${var.master_instance_size}"
  availability_zone = "${var.openstack_availability_zone}"
  key_pair = "${var.openstack_keypair}"
  security_groups = ["default"]
  metadata {
    ssh_user = "cloud-user"
  }
  volume {
    volume_id = "${openstack_blockstorage_volume_v1.master-docker-vol.id}"
  }
}


Further resources (eg. openstack volumes|floating_ip, digitalocean droplets, docker containers, ..)
can be defined via plugins.

At the end of every deployment cycle, terraform updates the `terraform.tstate` state file (which may
be stored on s3 or on shared storage) describing the actual infrastructure.

Upon configuration changes, terraform creates and shows a new execution plan,
that you can eventually apply.

As there’s no ansible provisioner, a terraform.py script can be used to extract an inventory file from a `terraform.tstate`.

Provisioning openstack on vmware infrastructure.

As I didn’t found extensive docs about provisioning Red Hat Openstack on a vmware infrastructure, I browsed the python code.

Python is a very expressive and clear language and you can get to the point in a moment!

I then was able to create the following instack.json to power-management a set of vmware machines.

Despite the many ways to pass ssh_* variables via ironic, the right way of running it via the instack.json is to:

– use the `pm_virt_type` instead of `ssh_virt_type`;
– express the ssh_key_content in the pm_password parameter like shown in the docs;
– set capabilities like profile and boot_option directly.

The key should be json-serialized on one line, replacing CR with ‘\n’.


{
    "nodes":[
        {
            "mac":[
                "00:0c:29:00:00:01"
            ],
            "capabilities": "profile:control,boot_option:local"
            "cpu":"8",
            "memory":"16384",
            "disk":"60",
            "arch":"x86_64",
            "pm_type":"pxe_ssh",
            "pm_virt_type": "vmware",
            "pm_addr":"172.18.0.1",
            "pm_user":"vmadmin",
            "pm_password":"-----BEGIN RSA PRIVATE KEY-----\nMY\nRSA\nKEY\n-----END RSA PRIVATE KEY-----"
        },
{..other nodes..}