KAFKA-2581: Run some existing ducktape tests with SSL

[rajinisivaram]

Parametrize console consumer sanity test, replication tests and benchmarks tests to run with both PLAINTEXT and SSL.

[ewencp]

Should these be added before or after the command line options? If we load them before, the default values for options would override custom settings from the consumer.config file even if the command line parameters were not specified.

[ijuma]

Interesting. Ideally, specified command-line settings would override the properties, but it seems like that would be a bigger change. Perhaps this should behave as the ConsoleConsumer until we can overhaul this. It looks like the change here does that, right?

[ewencp]

Agreed, ideally if they were specified they would override, but if unspecified it would use values from the file. Not sure how easy that is to get working with this options library. I could have sworn I checked one of the other tools and found it using the behavior I expected, but now can't find it. I don't think this is make-or-break. I was just raising it since the behavior is unintuitive to me and although the performance tools are less critical, we probably wouldn't want to change their behavior that significantly after releasing a version with support for the consumer.config option.

[rajinisivaram]

I do completely agree. However, I think all the tools currently do it this way and so I have kept it consistent. I will raise another JIRA to fix all the tools.

[ewencp]

@rajinisivaram This is looking good. I left a bunch of comments, but the core functionality that adds SSL test support seems solid. The changes I suggested are mostly targeted at code organization for the tests since the functionality seems ok.

[rajinisivaram]

@ewencp @ijuma Thank you for review comments. I will work on the changes tomorrow and submit an update soon.

[granders]

Minor but important - change these camel-case variables to snake_case for consistency

[rajinisivaram]

Test failure is unrelated to this PR.

Have addressed most of the issues raised. I didn't used mixin for security config, but have changed the code layout as suggested by @ewencp .

[granders]

self.test_context = test_context is not necessary

every subclass of Test has this assigned as long as you make the proper call to super(...).__init__(...) (which you did)

[granders]

@rajinisivaram
All tests passing: http://jenkins.confluent.io/job/kafka_system_tests_branch_builder/98/console

[granders]

I discussed this offline with @GuoZhang - to avoid having empty dummy files floating around, it may be better to delete this file and pass in empty string to in the SecurityConfig constructor in verifiable_producer (see comment below)