implement linode_domain resources

[displague]

Goal should be TF configs that look like:

resource "linode_domain" "example-com" {
   # the default type = "master" .. call it domain_type?
   soa_email = "admin@example.com"
   ttl_sec = "30"
   expire_sec = "30"
   refresh_sec = "30"
   name = "example.com"
   # interesting that the bare address "@" could be set this way..
   # but terraform would have to do this behind the scenes
   # ip_address = "${linode_instance.haproxy-www.ipv4_address}"
}

resource "linode_record" "A-@" {
  domain = "${linode_domain.example.id}"
  type = "A"
  name = "@"
  values = ["${linode_nodebalancer.example-nb.ipv4}"]
}

resource "linode_record" "AAAA-@" {
  domain = "${linode_domain.example.id}"
  type = "A"
  name = "@"
  values = ["${linode_nodebalancer.example-nb.ipv6}"]
}

resource "linode_record" "CNAME-www" {
  domain = "${linode_domain.example.id}"
  type = "CNAME"
  name = "www"
  values = "@" # should get auto-upgraded to array, can "value" be an alias to values?
}
...

[displague]

14 differs from like the example provided in this issue description:

linode_domain

• domain_type is required for linode_domain
• no support for bare address assignment (as proposed in the "interesting" comment block)

linode_domain_record

• domain is domain_id
• linode_domain_record rather than linode_record
• record_typerather than type
• values is target and does not support lists

These changes were made to meet Hashicorp advice to make a Terraform provider match the provider API as closely as possible.

[paddycarver]

The only part of this that makes me o.O is "values is target and does not support lists", but if the API doesn't support lists, the provider shouldn't, either. :) Otherwise, that seems like a fair enough design to me, and mirrors how the Google provider does its DNS design, as far as I can tell.