Add scripts/snabb_doc.sh

[eugeneia]

I added a new cron job “SnabbDoctor” to davos that will render and publish HTML renderings of our documentation.

1. the current release's documentation can be found at http://snabbco.github.io/
2. a tags documentation can be found at tag/<tag>.html, e.g. http://snabbco.github.io/tag/v2016.03.html
3. Pull Requests have a new status that points to the documentation for that PR at sha1/<sha1>.html

[eugeneia]

Or so I thought, bear with me to figure out why SnabbDoctor failed on this PR.

[wingo]

Very nice work! LGTM; I guess you are the upstream for this though?

[lukego]

@eugeneia Great work!

Can you please make a plan with @domenkozar to migrate all of this infrastructure into the nixops-managed snabblab universe? I would like to phase out running infrastructure on single-point-of-failure servers and with out-of-tree scripts e.g. cron jobs. This is fragile and we are lucky to have gotten away with it for as long as we have.

I would then see what solution you guys cook up and adopt that for the little script that mirrors registered branches on the SnabbCo repo :).

[domenkozar]

@eugeneia @lukego I can add this cronjob to https://github.com/snabblab/snabblab-nixos/ repository and configure it to run on eiger.

@eugeneia

What credentials are you using for github?
Can you paste me the cronjob line currently on davos?

Thanks!

[lukego]

@domenkozar @eugeneia I believe we have a dependency here on snabblab/snabblab-nixos#13. That issue is closed but I am not sure if we have verified it working.

I also think we need to be conscious of which Github credentials we install on a shared machine like eiger. This should not include write access to the Snabb repository for example. We should either lock down the Github permissions to a safe level or host them somewhere more locked-down.

Relatedly: is it a good or a bad idea to make Hydra execute the builds and tests and for SnabbBot to check the results and report to Github? (Why?)