Introduce a BackupExecutor and SourceContext

gems/gitlab-backup-cli/lib/gitlab/backup/cli.rb

@@ -7,11 +7,13 @@ module Gitlab
   module Backup
     # GitLab Backup CLI
     module Cli
+      autoload :BackupExecutor, 'gitlab/backup/cli/backup_executor'
       autoload :Commands, 'gitlab/backup/cli/commands'
       autoload :Dependencies, 'gitlab/backup/cli/dependencies'
       autoload :BackupMetadata, 'gitlab/backup/cli/backup_metadata'
       autoload :Output, 'gitlab/backup/cli/output'
       autoload :Runner, 'gitlab/backup/cli/runner'
+      autoload :SourceContext, 'gitlab/backup/cli/source_context'
       autoload :Shell, 'gitlab/backup/cli/shell'
       autoload :Tasks, 'gitlab/backup/cli/tasks'
       autoload :Utils, 'gitlab/backup/cli/utils'

gems/gitlab-backup-cli/lib/gitlab/backup/cli/backup_executor.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Backup
+    module Cli
+      # This is responsible for executing a Backup operation
+      #
+      # A Backup Executor handles the creation and deletion of
+      # temporary environment necessary for a backup to happen
+      #
+      # It also allows for multiple backups to happen in parallel
+      # without one overwriting data from another
+      class BackupExecutor
+        attr_reader :context, :metadata, :workdir, :archive_directory
+
+        # @param [Gitlab::Backup::Cli::SourceContext] context
+        def initialize(context:)
+          @context = context
+          @metadata = build_metadata
+          @workdir = create_temporary_workdir!
+          @archive_directory = context.backup_basedir.join(metadata.backup_id)
+        end
+
+        def execute
+          execute_all_tasks
+
+          archive!
+        end
+
+        # At the end of a successful backup, call this to release temporary resources
+        def release!
+          FileUtils.rm_rf(workdir)
+        end
+
+        private
+
+        def build_metadata
+          @metadata = Gitlab::Backup::Cli::BackupMetadata.build(gitlab_version: context.gitlab_version)
+        end
+
+        def execute_all_tasks
+          # TODO: when we migrate targets to the new codebase, recreate options to have only what we need here
+          # https://gitlab.com/gitlab-org/gitlab/-/issues/454906
+          options = ::Backup::Options.new
+
+          Gitlab::Backup::Cli::Tasks.all.each do |t|
+            task = t.new(context: context, options: options)
+            Gitlab::Backup::Cli::Output.info("Executing Backup of #{task.human_name}...")
+
+            duration = measure_duration do
+              task.backup!(workdir, metadata.backup_id)
+            end
+
+            Gitlab::Backup::Cli::Output.success("Finished Backup of #{task.human_name}! (#{duration.in_seconds}s)")
+          end
+        end
+
+        def archive!
+          # TODO: create a single-file archive instead of moving everything to a directory
+          # https://gitlab.com/gitlab-org/gitlab/-/issues/454832
+          FileUtils.mkdir(archive_directory)
+          workdir.glob('*').each { |entry| FileUtils.mv(entry, archive_directory) }
+        end
+
+        # @return [Pathname] temporary directory
+        def create_temporary_workdir!
+          # Ensure base directory exists
+          FileUtils.mkdir_p(context.backup_basedir)
+
+          Pathname(Dir.mktmpdir('backup', context.backup_basedir))
+        end
+
+        def measure_duration
+          start = Time.now
+          yield
+
+          ActiveSupport::Duration.build(Time.now - start)
+        end
+      end
+    end
+  end
+end

gems/gitlab-backup-cli/lib/gitlab/backup/cli/source_context.rb

+# frozen_string_literal: true
+
+module Gitlab
+  module Backup
+    module Cli
+      # This context is equivalent to a Source Install or GDK instance
+      #
+      # Any specific information from the GitLab installation will be
+      # automatically discovered from the current machine
+      class SourceContext
+        def gitlab_version
+          # TODO: decouple from Rails codebase
+          Gitlab::VERSION
+        end
+
+        def backup_basedir
+          # TODO: decouple from Rails codebase, load from gitlab.yml file
+          Rails.root.join('tmp/backups')
+        end
+      end
+    end
+  end
+end

gems/gitlab-backup-cli/spec/gitlab/backup/cli/backup_executor_spec.rb

+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Backup::Cli::BackupExecutor do
+  let(:context) { build_fake_context }
+
+  subject(:executor) { described_class.new(context: context) }
+
+  after do
+    executor.release!
+  end
+
+  describe '#initialize' do
+    it 'creates a workdir' do
+      expect(executor.workdir).to be_a(Pathname)
+      expect(executor.workdir).to be_directory
+    end
+
+    it 'initializes metadata' do
+      expect(executor.metadata).to be_a(Gitlab::Backup::Cli::BackupMetadata)
+    end
+  end
+
+  describe '#release!' do
+    it 'removes the workdir' do
+      expect { executor.release! }.to change { executor.workdir.exist? }.from(true).to(false)
+    end
+  end
+end

gems/gitlab-backup-cli/spec/support/helpers.rb

 # frozen_string_literal: true
 
+FakeContext = Struct.new(:gitlab_version, :backup_basedir, keyword_init: true)
+
 def spec_path
   Pathname.new(__dir__).join('..').expand_path
 end
@@ -11,3 +13,7 @@ def temp_path
 def stub_env(var, return_value)
   stub_const('ENV', ENV.to_hash.merge(var => return_value))
 end
+
+def build_fake_context
+  FakeContext.new(gitlab_version: '16.10', backup_basedir: temp_path.join('backups'))
+end