Redis authentication support

[davidwadden]

Inspired by #187

I'm interested in deploying Conductor to an environment that mandates Redis authentication. I've followed a similar pattern as #187 for adding a password field to Host.java which then in turn is passed through the HostsUpdater.java and set at the construction of the JedisConnectionFactory.java.

Interestings / questions:

• I only added a single constructor overload to Host.java. Do you want any additional overloads that accept the password?.
• The RedisAuthenticationIntegrationTest.java that was added to cover Redis authentication introduces a testCompile dependency on embedded-redis
  • This dependency does not work on Windows, prefer not to have this test at all?
• Host#toString masks the contents of the password field. Just a little non-standard
• Any additional test coverage I may have missed?

Also, noticed constructing a Host to be getting a bit complicated with the overloads. Would you entertain another PR to introduce a HostBuilder to simplify this?

[kishorekasi]

It will be useful to also add another testcase showing failure to connect to redisServer (with Auth) and client (no auth).

[davidwadden]

I had to drop from the DynoJedisClient down to the JedisConnectionFactory to get any kind of valuable unhappy path tests. I've added test methods to cover these cases from a lower layer, with the following cases added:

• Connect failed
• Password required
• Invalid password

[kishorekasi]

If embedded-redis doesn't work on Windows, use conditional ignore (https://junit.org/junit4/javadoc/4.12/org/junit/Assume.html) to ignore such tests

[kishorekasi]

Also I am curious to know why embedded-redis doesn't work on windows

[davidwadden]

It looks like a change introduced on the Spinnaker fork of kstyrc/embedded-redis (which smelled abandoned to me). I saw it noted on the README of the Spinnaker fork.

The reason is the library actually embeds OS-specific executables that are executed as separate processes.

I will follow your recommendation to conditionally ignore this test and make sure things are green on Windows.

[davidwadden]

This change is reflected here. Checked the tests are skipped on Windows

@Before
public void setUp() throws Exception {
	// skip tests on windows due to https://github.com/spinnaker/embedded-redis#redis-version
	Assume.assumeFalse(System.getProperty("os.name").toLowerCase().startsWith("win"));
}