Adds new plan_outputs functionality to allow configuring what to do with plans

[ross]

• Plumbing for plan_output support, configurable from the config file
• Port existing logger output to a plan_output ^
• Create a Markdown plan_output
• Create a HTML plan_output

/cc @wrouesnel
/cc Fixes #155

[ross]

The config for these work just work like the providers, e.g.:

---
manager:
  include_meta: true
  max_workers: 4
  plan_outputs:
    logger:
      class: octodns.provider.plan.PlanLogger
      level: 'info'
    markdown:
      class: octodns.provider.plan.PlanMarkdown

And just like providers you can use arbitrary modules/classes you have on the python path so it's trivial to hook something custom in, e.g. PlanGitHubComment. If I was writing that I'd have it inherit from PlanMarkdown, override run, call super, and pass in a StringIO as fh. That'd give you the output which you could turn around and submit as a comment on the GitHub PR.

What follows is an example of where the markdown outout is right now. The main bit blocking it from being a real solution is that there's not a good/easy way to stringify the value/values of the various records types. The existing `repr stuff is what's currently used for the log output, but that a pretty specific setup targeted at the existing logging. Not ideal for markdown and other outputs. I will circle back and think about what makes sense to wrap that up.

Fwiw, HTML would probably be a better output format for GitHub comments as you could fancier tables. In general open to thoughts/suggestions on the best formatting for the output

githubtest.net.

powerdns

Name	Type	Existing TTL	New TTL	Existing Value	New Value	Source
	A	300	300	todo	todo	config
cname	CNAME	300	300	todo	todo	config

Summary: Creates=0, Updates=2, Deletes=0, Existing Records=17

[ross]

Pushed an update with the following format. I'm relatively happy with it. Seems to be about the best I can manage with markdown tables.

githubtest.net.

powerdns

Operation	Name	Type	TTL	Value	Source
Update		A	300	1.2.3.5; 1.2.3.6
			300	2.2.3.5; 2.2.3.6; NA-US: 5.5.5.5, 6.6.6.6	config
Delete	aaaa	AAAA	600	2601:644:500:e210:62f8:1dff:feb8:947a
Update	mx	MX	300	'10 smtp-4.githubtest.net.'; '20 smtp-2.githubtest.net.'; '30 smtp-3.githubtest.net.'; '40 smtp-1.githubtest.net.'
			300	'100 smtp-4.githubtest.net.'; '200 smtp-2.githubtest.net.'; '300 smtp-3.githubtest.net.'; '400 smtp-1.githubtest.net.'	config
Update	cname	CNAME	300	githubtest.net.
			600	githubtest.net.	config
Create	cx	A	3600	1.2.3.4	config

Summary: Creates=1, Updates=3, Deletes=1, Existing Records=17

[ross]

Added a PlanHtml that outputs the following. I think the values are a bit easier to read and the colspan support is nice.

githubtest.net.

powerdns

Operation	Name	Type	TTL	Value	Source
Update		A	300	1.2.3.5 1.2.3.6
			300	2.2.3.5 2.2.3.6 NA-US: 5.5.5.5, 6.6.6.6	config
Delete	aaaa	AAAA	600	2601:644:500:e210:62f8:1dff:feb8:947a
Update	mx	MX	300	'10 smtp-4.githubtest.net.' '20 smtp-2.githubtest.net.' '30 smtp-3.githubtest.net.' '40 smtp-1.githubtest.net.'
			300	'100 smtp-4.githubtest.net.' '200 smtp-2.githubtest.net.' '300 smtp-3.githubtest.net.' '400 smtp-1.githubtest.net.'	config
Update	cname	CNAME	300	githubtest.net.
			600	githubtest.net.	config
Create	cx	A	3600	1.2.3.4	config
Summary: Creates=1, Updates=3, Deletes=1, Existing Records=17

[wrouesnel]

These look reasonably nice - certainly an improvement over trying to pipe the summary into the GH comment.

The framework being extensible should allow enough customization - for our in-house application I would probably make it a lot simpler or a more paragraphing style, but it's not a fully formed thought yet.

I'm basically planning to deploy this branch Monday inhouse for us to see how it goes.

[ross]

octoDNS Plan for 12deadbeef34

githubtest.net.

powerdns

Operation	Name	Type	TTL	Value	Source
Update		A	300	2.2.3.5 2.2.3.6
			300	1.2.3.5 1.2.3.6	config
Summary: Creates=0, Updates=1, Deletes=0, Existing Records=17

Automatically generated by PlanGitHubPr

[ross]

Comment above was auto generated and attached to this issue with a wrapper around the html plan. I'll probably turn it into a standalone thing published separate from octoDNS.

[xt0rted]

@ross was PlanGitHubPr published anywhere? This looks to do exactly what I'm trying to setup right now.

[ross]

I haven't, but here's all the code that was involved in the quick test/POC.

#
#
#

from __future__ import absolute_import, division, print_function, \
    unicode_literals

from StringIO import StringIO
from github import Github
from logging import getLogger
from octodns.provider.plan import PlanHtml
from os import environ


class PlanGitHubPr(PlanHtml):
    NEEDLE = '<!--- octodns/plan --->'

    log = getLogger('PlanGitHubPr')

    def run(self, plans, *args, **kwargs):
        try:
            access_token = environ['OCTODNS_PLAN_ACCESS_TOKEN']
            repo_name = environ['OCTODNS_PLAN_REPO']
            pull_number = int(environ['OCTODNS_PLAN_PULL'])
            sha = environ['OCTODNS_PLAN_SHA']
        except KeyError as e:
            self.log.warn('missing required env var %s', e.args[0])
            return

        github = Github(access_token)
        repo = github.get_repo(repo_name, lazy=True)
        pull = repo.get_pull(pull_number)

        buf = StringIO()
        super(PlanGitHubPr, self).run(plans, fh=buf, *args, **kwargs)

        for comment in pull.get_issue_comments():
            if self.NEEDLE in comment.body:
                break

        body = '''{needle}

## octoDNS Plan for {sha}

{plan}

Automatically generated by {klass}
'''.format(needle=self.NEEDLE, sha=sha, plan=buf.getvalue(),
           klass=self.__class__.__name__)

        if comment and self.NEEDLE in comment.body:
            # update this one
            self.log.info('%s/pull/%d plan updated', repo_name, pull_number)
            comment.edit(body)
        else:
            # create a new one
            self.log.info('%s/pull/%d plan created', repo_name, pull_number)
            pull.create_issue_comment(body)

There'll likely be full/formal support in the future, but there's no timeline on that so I wouldn't recommend waiting if it's something you're looking for.