Read stored certificate file, or use the data in the ENV var as fallback

[kreeger]

I really miss the ability to feed a certificate's .pem data into an ENV var, since this is (at least) how we've got it setup on a few of our Heroku instances, but this was taken away as of v2.2.3 (I think). This adds that functionality back, but also retains the new functionality of providing the file path (and makes that a first-attempt priority).

[kaneda]

Why not use the dotenv gem?

[kreeger]

If we used the dotenv gem, we'd still need to work with a path to a local file somewhere, right? And we would rather not have our cert file sitting as a file somewhere (in order to get read in), and that includes not having it checked into our git repo.

Unless I'm misunderstanding the purpose of dotenv? I haven't used it that extensively.

[kaneda]

@kreeger I guess I'm confused as to the intention: where do you want to store the PEM file?

[kreeger]

@kaneda We're storing the already-read-in contents of the PEM file in the ENV setting itself. So instead of APN_CERTIFICATE containing a file path, it contains the entire contents of the file.

[kaneda]

@kreeger gotcha, so dotenv probably won't help with this. You could submit a patch to https://github.com/nomad/houston/blob/master/lib/houston/client.rb#L30 that allows it to take in a File obj or IO obj instead then read from it.

[kreeger]

@kaneda that's what this PR is for! :D

[kaneda]

@kreeger see comments.

[kreeger]

@kaneda Pull request updated; there wasn't a prior README section for adding configuration details, so I added one.

[kaneda]

Looks good to me, you've got my :shipit:

[courtsimas]

:+1:

[kattrali]

Thanks, @kreeger!