Add service to clean up repository archive cache

Replace invocation of `find` with Ruby code that matches old cached
files in a better, and safe way to avoid data-integrity issues.

app/models/repository.rb

@@ -11,16 +11,6 @@ class Repository
 
   attr_accessor :path_with_namespace, :project
 
-  def self.clean_old_archives
-    Gitlab::Metrics.measure(:clean_old_archives) do
-      repository_downloads_path = Gitlab.config.gitlab.repository_downloads_path
-
-      return unless File.directory?(repository_downloads_path)
-
-      Gitlab::Popen.popen(%W(find #{repository_downloads_path} -not -path #{repository_downloads_path} -mmin +120 -delete))
-    end
-  end
-
   def initialize(path_with_namespace, project)
     @path_with_namespace = path_with_namespace
     @project = project

app/services/repository_archive_clean_up_service.rb

@@ -0,0 +1,42 @@
+class RepositoryArchiveCleanUpService
+  ALLOWED_ARCHIVE_EXTENSIONS = %w[tar tar.bz2 tar.gz zip].join(',').freeze
+  LAST_MODIFIED_TIME_IN_MINUTES = 120
+
+  def initialize(mmin = LAST_MODIFIED_TIME_IN_MINUTES)
+    @mmin = mmin
+    @path = Gitlab.config.gitlab.repository_downloads_path
+  end
+
+  def execute
+    Gitlab::Metrics.measure(:repository_archive_clean_up) do
+      return unless File.directory?(path)
+
+      clean_up_old_archives
+      clean_up_empty_directories
+    end
+  end
+
+  private
+
+  attr_reader :mmin, :path
+
+  def clean_up_old_archives
+    Dir.glob("#{path}/**.git/*{#{ALLOWED_ARCHIVE_EXTENSIONS}}") do |filename|
+      File.delete(filename) if older?(filename)
+    end
+  end
+
+  def older?(filename)
+    File.exist?(filename) && File.new(filename).mtime < (Time.now - mmin * 60)
+  end
+
+  def clean_up_empty_directories
+    Dir.glob("#{path}/**.git/").reverse_each do |dir|
+      Dir.rmdir(dir) if empty?(dir)
+    end
+  end
+
+  def empty?(dir)
+    (Dir.entries(dir) - %w[. ..]).empty?
+  end
+end

app/workers/repository_archive_cache_worker.rb

@@ -4,6 +4,6 @@ class RepositoryArchiveCacheWorker
   sidekiq_options queue: :default
 
   def perform
-    Repository.clean_old_archives
+    RepositoryArchiveCleanUpService.new.execute
   end
 end

spec/models/repository_spec.rb

@@ -1172,30 +1172,6 @@ describe Repository, models: true do
     end
   end
 
-  describe '.clean_old_archives' do
-    let(:path) { Gitlab.config.gitlab.repository_downloads_path }
-
-    context 'when the downloads directory does not exist' do
-      it 'does not remove any archives' do
-        expect(File).to receive(:directory?).with(path).and_return(false)
-
-        expect(Gitlab::Popen).not_to receive(:popen)
-
-        described_class.clean_old_archives
-      end
-    end
-
-    context 'when the downloads directory exists' do
-      it 'removes old archives' do
-        expect(File).to receive(:directory?).with(path).and_return(true)
-
-        expect(Gitlab::Popen).to receive(:popen)
-
-        described_class.clean_old_archives
-      end
-    end
-  end
-
   describe "#keep_around" do
     it "stores a reference to the specified commit sha so it isn't garbage collected" do
       repository.keep_around(sample_commit.id)

spec/services/repository_archive_clean_up_service_spec.rb

@@ -0,0 +1,31 @@
+require 'spec_helper'
+
+describe RepositoryArchiveCleanUpService, services: true do
+  describe '#execute' do
+    let(:path) { Gitlab.config.gitlab.repository_downloads_path }
+
+    subject(:service) { described_class.new }
+
+    context 'when the downloads directory does not exist' do
+      it 'does not remove any archives' do
+        expect(File).to receive(:directory?).with(path).and_return(false)
+
+        expect(service).not_to receive(:clean_up_old_archives)
+        expect(service).not_to receive(:clean_up_empty_directories)
+
+        service.execute
+      end
+    end
+
+    context 'when the downloads directory exists' do
+      it 'removes old archives' do
+        expect(File).to receive(:directory?).with(path).and_return(true)
+
+        expect(service).to receive(:clean_up_old_archives)
+        expect(service).to receive(:clean_up_empty_directories)
+
+        service.execute
+      end
+    end
+  end
+end