Pass an environment variable into SBT to use in a Specs2 test? - sbt

Question

What is the correct way of passing in an environment variable into SBT so that it can be accessed using Specs2? (And then retrieving the value in Specs2.) The environment variable will contain an API key to use for testing.
It needs to be an environment variable to work with Travis CI's encrypted environment variable functionality[1]
My setup:
SBT 0.13.0
Specs2 2.3.4
Travis CI
Edit: bonus points if somebody can link to an open-source repo that does this. There must be a few!
[1] Using secret api keys on travis-ci

Answer 1

I guess that you can encrypt your key with the travis api and get:
xxxEncryptedxxx
Then you can use the CommandLineArguments trait to pass arguments from the command-line in SBT to your specification.
In .travis.yml
sbt ++$TRAVIS_SCALA_VERSION testOnly *MySpec* -- key xxxEncryptedxxx
In MySpec.scala
class MySpec extends mutable.Specification with CommandLineArguments {
"this is an API test" >> {
arguments.commandLine.value("key").map { k =>
callApi(k) must beOk
}.getOrElse(ko("you need to pass a key on the command line"))
}
}

Answer 2

From you questions, I presume you're looking to pass secure environment variables using Travis's built-in support for encryption?
If so the environment variable is set before SBT is run, so it should be available to all processes. I don't use Specs, but the standard JVM way to get environment variable is to use System.getenv(String). It's possible that sbt deletes the environment variables before running Specs; if that's true then fixing that has to be done in your build.sbt somehow, and isn't specific to Travis.