short-cycle: check for presence of media playlists in the master

[iameli]

So we had a region down for a number of hours last night - specifically, RTMP ingest worked, but the appropriate playback routes weren't getting added to Consul. So any time playback was attempted, an HTTP 200 was returned along with this playlist:

▶ curl https://region-cdn.livepeer.com/hls/doesnotexist/index.m3u8
#EXTM3U
#EXT-X-ERROR: Stream open failed
#EXT-X-ENDLIST

The short cycle streams apparently did not treat this as an error condition — I assume it was determining that all 0 of the 0 media playlists were returning data correctly or some such. This should throw an error.

[thedeeno]

I'll update the short-cycle to check for this and send a page.

[wohlner]

Is this done?

[thedeeno]

@wohlner yup! Sorry for not closing right away.