Make sidekiq-cluster --dryrun emit the literal commands

This is useful if you want to expand queues using the query selector,
but don't want to actually start the process (perhaps because you have
your own process supervisor).

lib/gitlab/sidekiq_cluster.rb

 # frozen_string_literal: true
 
+require 'shellwords'
+
 module Gitlab
   module SidekiqCluster
     # The signals that should terminate both the master and workers.
@@ -73,9 +75,9 @@ module Gitlab
       counts = count_by_queue(queues)
 
       cmd = %w[bundle exec sidekiq]
-      cmd << "-c #{self.concurrency(queues, min_concurrency, max_concurrency)}"
+      cmd << "-c#{self.concurrency(queues, min_concurrency, max_concurrency)}"
       cmd << "-e#{env}"
-      cmd << "-gqueues: #{proc_details(counts)}"
+      cmd << "-gqueues:#{proc_details(counts)}"
       cmd << "-r#{directory}"
 
       counts.each do |queue, count|
@@ -83,7 +85,7 @@ module Gitlab
       end
 
       if dryrun
-        puts "Sidekiq command: #{cmd}" # rubocop:disable Rails/Output
+        puts Shellwords.join(cmd) # rubocop:disable Rails/Output
         return
       end
 
@@ -112,7 +114,7 @@ module Gitlab
         else
           "#{queue} (#{count})"
         end
-      end.join(', ')
+      end.join(',')
     end
 
     def self.concurrency(queues, min_concurrency, max_concurrency)

lib/gitlab/sidekiq_cluster/cli.rb

@@ -64,7 +64,9 @@ module Gitlab
             'No queues found, you must select at least one queue'
         end
 
-        @logger.info("Starting cluster with #{queue_groups.length} processes")
+        unless @dryrun
+          @logger.info("Starting cluster with #{queue_groups.length} processes")
+        end
 
         @processes = SidekiqCluster.start(
           queue_groups,

spec/bin/sidekiq_cluster_spec.rb

 # frozen_string_literal: true
 
 require 'spec_helper'
+require 'shellwords'
 
 describe 'bin/sidekiq-cluster' do
   using RSpec::Parameterized::TableSyntax
@@ -18,9 +19,9 @@ describe 'bin/sidekiq-cluster' do
         output, status = Gitlab::Popen.popen(cmd, Rails.root.to_s)
 
         expect(status).to be(0)
-        expect(output).to include('"bundle", "exec", "sidekiq"')
-        expect(output).to include(included)
-        expect(output).not_to include(excluded)
+        expect(output).to include('bundle exec sidekiq')
+        expect(Shellwords.split(output)).to include(included)
+        expect(Shellwords.split(output)).not_to include(excluded)
       end
     end
   end
@@ -36,9 +37,9 @@ describe 'bin/sidekiq-cluster' do
         output, status = Gitlab::Popen.popen(cmd, Rails.root.to_s)
 
         expect(status).to be(0)
-        expect(output).to include('"bundle", "exec", "sidekiq"')
-        expect(output).to include('-qdefault,1')
-        expect(output).to include('-qcronjob:ci_archive_traces_cron,1')
+        expect(output).to include('bundle exec sidekiq')
+        expect(Shellwords.split(output)).to include('-qdefault,1')
+        expect(Shellwords.split(output)).to include('-qcronjob:ci_archive_traces_cron,1')
       end
     end
   end