NS1: Single Value Records with no answer raises IndexError

So just dumping our zone, got this error. We had a PTR record in our forward zone in NS1, no idea why, but it also had no answers.

Response from NS1

PTR, {u'domain': u'asmith.net', u'short_answers': [], u'link': None, u'ttl': 3600, u'tier': 1, u'type': u'PTR', u'id': u'1b05cd7943dde9d3'}

Error

Traceback (most recent call last):
  File "/Users/asmith/as-octodns/venv/bin/octodns-dump", line 11, in <module>
    sys.exit(main())
  File "/Users/asmith/as-octodns/venv/lib/python2.7/site-packages/octodns/cmds/dump.py", line 31, in main
    manager.dump(args.zone, args.output_dir, args.lenient, *args.source)
  File "/Users/asmith/as-octodns/venv/lib/python2.7/site-packages/octodns/manager.py", line 362, in dump
    source.populate(zone, lenient=lenient)
  File "/Users/asmith/as-octodns/venv/lib/python2.7/site-packages/octodns/provider/ns1.py", line 156, in populate
    record = Record.new(zone, name, data_for(_type, record),
  File "/Users/asmith/as-octodns/venv/lib/python2.7/site-packages/octodns/provider/ns1.py", line 76, in _data_for_CNAME
    'value': record['short_answers'][0],
IndexError: list index out of range

The record doesn’t make sense, plus why have a record with no answers. I believe this should probably throw a ValidationError with a “No Records” reason.

Also at least for NSOne, it’s another convenience, you don’t have to put the . in, and it will still put it when you query for it.

[yzguy]

So after some poking around. I now realize/understand the change that would need to happen in the NS1 Provider.

Originally I had a PTR record with no answers, which is the same method for CNAME and ALIAS

So before even getting to the validate method of octodns/record.py inValueMixin, it’s failing with my original error

Traceback (most recent call last):
  File "/Users/yzguy/Projects/yzguy-octodns/venv/bin/octodns-dump", line 11, in <module>
    sys.exit(main())
  File "/Users/yzguy/Projects/yzguy-octodns/venv/lib/python2.7/site-packages/octodns/cmds/dump.py", line 31, in main
    manager.dump(args.zone, args.output_dir, args.lenient, *args.source)
  File "/Users/yzguy/Projects/yzguy-octodns/venv/lib/python2.7/site-packages/octodns/manager.py", line 362, in dump
    source.populate(zone, lenient=lenient)
  File "/Users/yzguy/Projects/yzguy-octodns/venv/lib/python2.7/site-packages/octodns/provider/ns1.py", line 155, in populate
    record = Record.new(zone, name, data_for(_type, record),
  File "/Users/yzguy/Projects/yzguy-octodns/venv/lib/python2.7/site-packages/octodns/provider/ns1.py", line 75, in _data_for_CNAME
    'value': record['short_answers'][0],
IndexError: list index out of range

So at least for NS1, when dumping/nooping it will give the error above if you have a CNAME, ALIAS, or PTR with no answers

I think _data_for_CNAME is the only method that needs this addition, the rest have a values = [] default, which would get caught during a length check in validation.

PR here: First PR here to handle the issues in NS1 Provider: https://github.com/github/octodns/pull/136

This fixes up NS1 to have a default value of None, and assign the answer if one exists in the API Response. This fixes the above issue, and validations will create a better user experience.

[yzguy]

All sounds good. I’m working on the change

I have it “working”, just need to fix up the tests/new ones

If you dump it without lenient you get

octodns.record.ValidationError: Invalid record test.yzguy.io.
  - missing value(s)

If you specify --lenient it will complete, giving the warning

2017-10-22T20:46:43  [140737049330624] WARNING Record Invalid record test.yzguy.io.
  - missing value(s)

and you’re YAML file will look like this

test:
  type: A

Which would be caught if you applied it with a

 octodns.record.ValidationError: Invalid record test.yzguy.io.
   - missing value(s)