We only use guid/ems_id, so pass those, not a hash

Don't break an interface for yet another option hash.

Change the tests to not care about the order of some of the CLI
arguments since awesome spawn builds them in hash insertion order and we
don't really care of the order of some of them anyway.

app/models/miq_worker.rb

@@ -359,14 +359,16 @@ def start_runner_via_fork
     pid
   end
 
-  def self.build_command_line(options)
-    require 'awesome_spawn'
-    raise ArgumentError, "expected options hash, received: #{options.class}" unless options.kind_of?(Hash)
-    raise ArgumentError, "missing :guid options key" unless options.key?(:guid)
+  def self.build_command_line(guid, ems_id = nil)
+    raise ArgumentError, "No guid provided" unless guid
 
+    require 'awesome_spawn'
     cmd = "#{Gem.ruby} #{runner_script}"
     cmd = "nice #{nice_increment} #{cmd}" if ENV["APPLIANCE"]
-    "#{AwesomeSpawn::CommandLineBuilder.new.build(cmd, options.merge(:heartbeat => nil))} #{name}"
+
+    options = {:guid => guid, :heartbeat => nil}
+    options[:ems_id] = ems_id if ems_id
+    "#{AwesomeSpawn::CommandLineBuilder.new.build(cmd, options)} #{name}"
   end
 
   def self.runner_script
@@ -376,7 +378,7 @@ def self.runner_script
   end
 
   def command_line
-    self.class.build_command_line(worker_options)
+    self.class.build_command_line(*worker_options.values_at(:guid, :ems_id))
   end
 
   def start_runner_via_spawn

spec/models/miq_worker_spec.rb

@@ -346,11 +346,6 @@ def check_has_required_role(worker_role_names, expected_result)
     end
 
     context "#command_line" do
-      it "with nil worker_options" do
-        allow(@worker).to receive(:worker_options).and_return(nil)
-        expect { @worker.command_line }.to raise_error(ArgumentError)
-      end
-
       it "without guid in worker_options" do
         allow(@worker).to receive(:worker_options).and_return({})
         expect { @worker.command_line }.to raise_error(ArgumentError)
@@ -369,7 +364,10 @@ def check_has_required_role(worker_role_names, expected_result)
           ENV['APPLIANCE'] = 'true'
           cmd = @worker.command_line
           expect(cmd).to start_with("nice +10")
-          expect(cmd).to end_with("--ems-id 1234 --guid #{@worker.guid} --heartbeat MiqWorker")
+          expect(cmd).to include("--ems-id 1234")
+          expect(cmd).to include("--guid #{@worker.guid}")
+          expect(cmd).to include("--heartbeat")
+          expect(cmd).to end_with("MiqWorker")
         ensure
           # ENV['x'] = nil deletes the key because ENV accepts only string values
           ENV['APPLIANCE'] = old_env