Refactor gen log throttle

[jcantrill]

blocked on #350

[jcantrill]

[merge]

[jcantrill]

[merge] ansible dependency is fixed.

[jcantrill]

[merge] test flake?

[openshift-bot]

Evaluated for aggregated logging merge up to 73c2ea7

[openshift-bot]

Aggregated Logging Merge Results: FAILURE (https://ci.openshift.redhat.com/jenkins/job/test-origin-aggregated-logging/1230/) (Base Commit: c13ad15)

[richm]

@jcantrill The problem is that YAML.load_file() will return false if the file has no yaml in it. map is not a valid method for the false class. The default file /etc/fluent/configs.d/user/throttle-config.yaml contains only comments.

$ pwd
~/origin-aggregated-logging
$ irb
irb(main):001:0> require 'yaml'
=> true
irb(main):002:0> YAML.load_file("fluentd/configs.d/user/throttle-conf.yaml")
=> false
irb(main):003:0> YAML.load_file("fluentd/configs.d/user/throttle-conf.yaml").map
NoMethodError: undefined method `map' for false:FalseClass
Did you mean?  tap
	from (irb):3
	from /usr/bin/irb:11:in `<main>'

This is the error from https://ci.openshift.redhat.com/jenkins/job/test-origin-aggregated-logging/1230/s3/download/logs/containers/k8s_fluentd-elasticsearch.1fb423d7_logging-fluentd-cgslb_logging_ec2283af-1583-11e7-a65a-0ecf144b3860_828d9bc5.log

generate_throttle_configs.rb:222:in `<main>': undefined method `map' for false:FalseClass (NoMethodError)

[openshift-bot]

Evaluated for origin aggregated logging merge up to 73c2ea7

[openshift-bot]

Origin Aggregated Logging Merge Results: SUCCESS (https://ci.openshift.redhat.com/jenkins/job/merge_pull_request_origin_aggregated_logging/10/) (Base Commit: 6f90060)