[sos-devel] [RFC] wrap commands in /usr/bin/timeout when available

[Adam Stokes]

On 03/20/2012 02:39 PM, Jesse Jaggars wrote:
> On Tue, Mar 20, 2012 at 06:32:25PM +0000, Bryn M. Reeves wrote:
>> On 03/20/2012 06:21 PM, Jesse Jaggars wrote:
>>> Using `timeout` is great for our situation since it allows us to offer a
>>> shell to plugins (for easy pipelines). Also, there isn't much extra overhead
>>> since we are forking from python anyways.
>> That's true actually - I'd not thought of that extra side effect but
>> it's neat.
>>
>>> The only major downside is that we will rely on the binary to implement
>>> the timeout mechanism for us. This means that we either have to
>>> implement alternative timeout methods for platforms that lack `timeout`
>>> or fail to supply a timeout on those platforms. This is no worse than we
>>> do today, so it's not much of a downside I don't suppose.
>> Also true.. I think the fallback approach sounds like a good idea. This
>> would also let us work on distributions that ship pre-7.x coreutils.
>> Although I'd like to get timeout backported into the older Red Hat stuff
>> we can still run into machines with outdated packages.
>>
>>> Given that we will likely want to try to provide an alternative timeout
>>> method we should probably plan to plug in different implementations
>>> somehow. Currently the method to fork a subprocess and do some work is
>>> just a thin wrapper around subprocess.Popen. It would make sense to
>>> allow a Policy object to override this implementation, though that might
>>> be overkill for now since we can see if `timeout` exists and use it or
>>> just do what we do now and hope for the best.
>> If we're going to allow falling back on Linux hosts too I reckon this
>> might be the way to go - policies can then look for a usable binary and
>> decide which way to go. Or maybe it's better in the general plugin
>> support code.. dunno - I think I'd need to see how it looked.
>>
>> Cheers,
>> Bryn.
>>
> I think, in the simplest form, this commit shows how we can do this:
>
> https://github.com/jhjaggars/sosreport/commit/2300c2e0d61ad6a241e82ffbcfcb72822f1f70ee
>
> This patch offers no policy-level customization, but that might not
> matter right away.
>
> Jesse
One thing, maybe add a default timeout param somewhere