Store and display container logs in Postgres database

[sebastian]

Telefonica has requested that it should be possible to view the container logs in the web interface. To satisfy this we must:

• persist Air logs in the Postgres database
• ship logs from the Cloak containers to the Air and persist these too

I suggest:

• We tag each log entry we store with their origin in a separate column so we can filter them by source
• We rotate logs after a month(?) to put a bound on the storage requirements

In terms of interface. In another ongoing pull-request I am slightly rejigging parts of the interface by renaming the activities monitor into system status. I moved the active queries section which used to be part of the activity monitor page to the queries page. Going forward I plan to make the system status page have tabs (like the queries page). These would be: "Overview", "Warnings", and "System logs" or something to that effect. The logs collected as a result of this issue would go into the latter tab.

I also suggest it's a live view that supports tailing the log on demand. Filtering would also be good!

[sebastian]

If this is done before my systems status pull-request, then I suggest making the interface but holding off of merging until the other change has been completed.

[sebastian]

@cristianberneanu I have assigned the system status page pull to you. It contains what I envision to be the page with tabs where the logs are to be displayed as well.

[cristianberneanu]

Filtering would also be good!

I think filtering is overkill. We can show today's logs in realtime, in separate tabs for each source, and provide a button to download a compressed archive of the logs for offline storage and searching.