Remove PowerDNS

[aramprice]

What is this change about?

Remove PowerDNS

Please provide contextual information.

The PowerDNS package has not been updated since 2016. This commit removes:

• package
• job
• all config values under dns except domain_name
• models under src/bosh-director/lib/bosh/director/models/dns/
  • all mention or use of dns_db which was a separate database configuration for these models

What tests have you run against this PR?

✅ rake fly:unit ✅ rake fly:integration ✅ DB=mysql rake fly:integration

How should this change be described in bosh release notes?

PowerDNS job and associated code is removed.

Does this PR introduce a breaking change?

Yes, operators who use PowerDNS will need to migrate to an alternative before upgrading to this release.

---

• PR to remove bosh-deployment's misc/powerdns.yml
  • https://github.com/cloudfoundry/bosh-deployment/pull/459
• PR to remove PowerDNS from docs-bosh
  • https://github.com/cloudfoundry/docs-bosh/pull/829
• PR to remove --dns flag and functionality from bosh CLI
  • https://github.com/cloudfoundry/bosh-cli/pull/644
• PR to remove usage in Openstack CPI
  • https://github.com/cloudfoundry/bosh-openstack-cpi-release/pull/270

[aramprice]

Question from https://github.com/cloudfoundry/bosh-cli/pull/644#discussion_r1535886899

What happens when a director w/o PowerDNS receives a --dns flag on the instances or vms command?

cc @ystros

[aramprice]

Question from cloudfoundry/bosh-cli#644 (comment)

What happens when a director w/o PowerDNS receives a --dns flag on the instances or vms command?

cc @ystros

The director code returning a dns response currently always returns this field in the JSON, however it is only ever populated PowerDNS is enabled. see bosh-director/lib/bosh/director/jobs/vm_state.rb:49-56

Added an explicit test in the CLI to validate that PowerDNS-having-director responses are still handled: bosh-cli/director/vms_test.go:143-144

[beyhan]

Let's wait for another approval on this because the change is quite large.