Add support to custom xlogdir parameter

[mnencia]

Having a custom xlogdir location is desiderable for performances in many production environments

[kbarber-jenkins-bot]

Can one of the admins verify this patch?

[kbarber]

@mnecia I think the code itself looks good, but I would add an rspec-system test to ensure things still work when the xlog dir is provided. Its just too easy for this stuff not to work or be fragile esp. on older OS distros, so its not worth leaving it out of coverage.

[kbarber]

Also, this lacks any update to the README.md, can you ensure the parameter is documented there @mnencia?

[mnencia]

There isn't any test nor documentation also for the datadir parameter. I'll add both.

[kbarber]

@mnencia hey perfect, yes no coverage for datadir - adding that would be awesome. We do need to get better at adding those tests, my fault this time as I had a chance to do it - but yeah - we should be harder on ourselves. For example: I bet you a dollar putting in a test for xlogdir and/or datadir brings something to light :-).

[kbarber]

@mnencia hows it going?

[mnencia]

I'm sorry, but in the last two weeks I've been ultra-busy, and so I'll be until the end of PgConf.EU (1st November).

[kbarber]

@mnencia there is another user trying to solve the datadir problem. If you want, just try and solve the xlogdir problem for now so at least we can get this part solved - you don't have to boil the ocean. We can always get the custom datadir solved later.

[blewa]

Sent @mnencia a PR here (https://github.com/mnencia/puppetlabs-postgresql/pull/1). Let me know if that isn't everything that we need and I'll get it added.

[mnencia]

I've jut modified the system rspec. It should now work correctly.

[mnencia]

It's failing in Travis CI, but it passes both spec and spec:system target on my local system. I suspect that the failure is not related to this feature.