Fix MulticastLogger DEBUG mode

When passing the config/settings data to the `.apply_config_value`
method of Vmdb::Loggers, if the value was set to `DEBUG` the level
wouldn't be changed in the lower level logger to reflect that.

This is because the MulticastLogger is instantiated and defaulted at
DEBUG, but the logger it casts to (normally an instance of VMDBLogger)
would have it's level defaulted to `info`.  When `.apply_config_value`
is then called, it would compare the old value to the new one, and see
it as the same, even though it was different under the covers.

This means when a user attempts to do a `$log.debug "my message"`, the
message would then not be applied.

The fix here effectively makes sure we are defaulting the lower level
logger to the same log level as the parent, or the MulticastLogger.
When `.apply_config_value` is then eventually called, if the setting is
set to `DEBUG`, nothing will change, but the level will be set properly
for the lower level logger.  Anything level set higher than DEBUG will
function as it has.

* * *

There was also some additional tests added to the new test file,
`spec/lib/vmdb/loggers_spec.rb`, that covered some of the quirks of log
levels in a container config.  Since `$container_log` is set to use the
`lib/vmdb/loggers/container_logger.rb`, this means it's `#level=` method
is set to override the default and always set itself to "DEBUG".  This
is a bit confusing at first glace if you are trying to grok what is
happening in `lib/vmdb/loggers.rb`, as it can seem like the whole thing
wouldn't work as expected, and the level for the $container_log would be
overwritten with each log type.

lib/vmdb/loggers.rb

@@ -130,7 +130,10 @@ def self.create_loggers
     private_class_method :create_loggers
 
     def self.create_multicast_logger(log_file_path, logger_class = VMDBLogger)
-      MulticastLogger.new(logger_class.new(log_file_path)).tap do |l|
+      logger_instance = logger_class.new(log_file_path).tap do |logger|
+        logger.level = Logger::DEBUG
+      end
+      MulticastLogger.new(logger_instance).tap do |l|
         l.loggers << $container_log if ENV["CONTAINER"]
       end
     end

spec/lib/vmdb/loggers_spec.rb

@@ -0,0 +1,54 @@
+describe Vmdb::Loggers do
+  let(:log_file) { Rails.root.join("log", "foo.log").to_s }
+
+  def in_container_env(example)
+    old_env = ENV.delete('CONTAINER')
+    ENV['CONTAINER'] = 'true'
+    example.run
+  ensure
+    # ENV['x'] = nil deletes the key because ENV accepts only string values
+    ENV['CONTAINER'] = old_env
+  end
+
+  describe "#create_multicast_logger (private)" do
+    it "defaults the lower level loggers to `DEBUG`" do
+      log = described_class.send(:create_multicast_logger, log_file)
+
+      expect(log.loggers.first.level).to eq(Logger::DEBUG)
+      expect(log.loggers.to_a.size).to   eq(1)
+    end
+
+    context "in a container environment" do
+      around { |example| in_container_env(example) }
+
+      it "sets logger_instance and $container_log to debug" do
+        log = described_class.send(:create_multicast_logger, log_file)
+
+        expect(log.loggers.first.level).to     eq(Logger::DEBUG)
+        expect(log.loggers.to_a.last.level).to eq(Logger::DEBUG)
+      end
+    end
+  end
+
+  describe "#apply_config_value (private)" do
+    it "will update the main lower level logger instance" do
+      log = described_class.send(:create_multicast_logger, log_file)
+      described_class.send(:apply_config_value, {:foo => :info}, log, :foo)
+
+      expect(log.loggers.first.level).to eq(Logger::INFO)
+      expect(log.loggers.to_a.size).to   eq(1)
+    end
+
+    context "in a container environment" do
+      around { |example| in_container_env(example) }
+
+      it "will always keep $container_log as DEBUG" do
+        log = described_class.send(:create_multicast_logger, log_file)
+        described_class.send(:apply_config_value, {:foo => :info}, log, :foo)
+
+        expect(log.loggers.first.level).to     eq(Logger::INFO)
+        expect(log.loggers.to_a.last.level).to eq(Logger::DEBUG)
+      end
+    end
+  end
+end