Home DNS Refresh

Looks up the current external IP, and updates an Azure Zone A Record to that IP if its different.

The A Record must be resolvable, so that it may check if its the same or different.

Setup on Nomad as a periodic job

```hcl job "homednsrefresh" { datacenters = ["dc1"] type = "batch"

periodic { cron = "*/5 * * * * *" prohibit_overlap = false }

group "homednsrefresh" { count = 1 task "homednsrefresh" { driver = "docker"

  config {
    image = "ghcr.io/haribo256/haribo256/home-dns-refresh:<version>"

    args = [
      "--tenant-id", "<tenant-id>",
      "--subscription-id", "<subscription-id>",
      "--resource-group", "<resouce-group>",
      "--zone-name", "<azure-zone>",
      "--sub-domain", "<subdomain-on-azure-zone-to-update>",
      "--client-id", "<azure-client-id>",
      "--client-secret", "<azure-client-secret>"
    ]
  }

  restart {
    attempts = 0
    mode = fail
  }

  resources {
    cpu    = 100
    memory = 20
  }
}

} } ```