Re: container restart on logout


Graham Bleach
 

On 23 December 2016 at 09:21, Daniel Jones
<daniel.jones(a)engineerbetter.com> wrote:
Hmm, here's an idea that I haven't through and so is probably rubbish...

How about an immutability enforcer? Recursively checksum the expanded
contents of a droplet, and kill-with-fire anything that doesn't match it.
It'd need to be optional for folks storing ephemeral data on their ephemeral
disk, and a non-invasive (ie no changes to CF components) implementation
would depend on `cf ssh` or a chained buildpack, but maybe that's a nice
compromise that could be quicker to develop than waiting for mainline code
changes to CF?
An idea we've been kicking around is to ensure that app instance
containers never live longer than a certain time (eg. 3, 6, 12 or 24
hours).

This would ensure that we'd catch cases where apps weren't able to
cope with being rescheduled to different cells. It'd also strongly
discourage manual tweaks via ssh. It'd probably be useful for people
deploying apps to be able to initiate an aggressive version of this
behaviour to run in their testing pipelines, prior to production
deployment, to catch regressions in keeping state in app instances.

There's a naive implementation in my head that would work fine on
smaller installations by looping through app instances returned by the
API and restarting them.

Cheers,
Graham

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