From b59e44f0b11917a1e796a82f6ae487aa63c4c102 Mon Sep 17 00:00:00 2001
From: Gabriel Mazetto <gabriel@gitlab.com>
Date: Wed, 14 Feb 2024 06:02:13 +0100
Subject: [PATCH] Introduce Shell::Pipeline
---
.../lib/gitlab/backup/cli/shell.rb | 1 +
.../lib/gitlab/backup/cli/shell/pipeline.rb | 58 +++++++++++++
.../gitlab/backup/cli/shell/pipeline_spec.rb | 83 +++++++++++++++++++
3 files changed, 142 insertions(+)
create mode 100644 gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell/pipeline.rb
create mode 100644 gems/gitlab-backup-cli/spec/gitlab/backup/cli/shell/pipeline_spec.rb
diff --git a/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell.rb b/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell.rb
index 23d63ca90ae58..6107e14333f07 100644
--- a/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell.rb
+++ b/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell.rb
@@ -7,6 +7,7 @@ module Backup
module Cli
module Shell
autoload :Command, 'gitlab/backup/cli/shell/command'
+ autoload :Pipeline, 'gitlab/backup/cli/shell/pipeline'
end
end
end
diff --git a/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell/pipeline.rb b/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell/pipeline.rb
new file mode 100644
index 0000000000000..6a18c54ff5932
--- /dev/null
+++ b/gems/gitlab-backup-cli/lib/gitlab/backup/cli/shell/pipeline.rb
@@ -0,0 +1,58 @@
+# frozen_string_literal: true
+
+module Gitlab
+ module Backup
+ module Cli
+ module Shell
+ class Pipeline
+ # Result data structure from running a pipeline
+ #
+ # @attr [String] stderr
+ # @attr [Array<Process::Status>] status
+ # @attr [Float] duration
+ Result = Struct.new(:stderr, :status_list, :duration, keyword_init: true)
+
+ attr_reader :shell_commands
+
+ # @param [Array<Shell::Command>] shell_commands
+ def initialize(*shell_commands)
+ @shell_commands = shell_commands
+ end
+
+ # Run commands in pipeline with optional input or output redirection
+ #
+ # @param [IO|String|Array] input stdin redirection
+ # @param [IO|String|Array] output stdout redirection
+ # @return [Pipeline::Result]
+ def run_pipeline!(input: nil, output: nil)
+ start = Time.now
+ # Open3 writes on `err_write` and we receive from `err_read`
+ err_read, err_write = IO.pipe
+
+ # Pipeline accepts custom {Process.spawn} options
+ # stderr capture is always performed, stdin and stdout redirection
+ # are performed only when either `input` or `output` are present
+ options = { err: err_write } # redirect stderr to IO pipe
+ options[:in] = input if input # redirect stdin
+ options[:out] = output if output # redirect stdout
+
+ status_list = Open3.pipeline(*build_command_list, **options)
+ duration = Time.now - start
+
+ err_write.close # close the pipe before reading
+ stderr = err_read.read
+ err_read.close # close after reading to avoid leaking file descriptors
+
+ Result.new(stderr: stderr, status_list: status_list, duration: duration)
+ end
+
+ private
+
+ def build_command_list
+ @shell_commands.map(&:cmd_args)
+ end
+ end
+ end
+ end
+ end
+end
diff --git a/gems/gitlab-backup-cli/spec/gitlab/backup/cli/shell/pipeline_spec.rb b/gems/gitlab-backup-cli/spec/gitlab/backup/cli/shell/pipeline_spec.rb
new file mode 100644
index 0000000000000..ad2837af557c7
--- /dev/null
+++ b/gems/gitlab-backup-cli/spec/gitlab/backup/cli/shell/pipeline_spec.rb
@@ -0,0 +1,83 @@
+# frozen_string_literal: true
+
+require 'spec_helper'
+
+RSpec.describe Gitlab::Backup::Cli::Shell::Pipeline do
+ let(:command) { Gitlab::Backup::Cli::Shell::Command }
+ let(:printf_command) { command.new('printf "3\n2\n1"') }
+ let(:sort_command) { command.new('sort') }
+
+ subject(:pipeline) { described_class }
+
+ it { respond_to :shell_commands }
+
+ describe '#initialize' do
+ it 'accept single argument' do
+ expect { pipeline.new(printf_command) }.not_to raise_exception
+ end
+
+ it 'accepts multiple arguments' do
+ expect { pipeline.new(printf_command, sort_command) }.not_to raise_exception
+ end
+ end
+
+ describe '#run_pipeline!' do
+ it 'returns a Pipeline::Status' do
+ true_command = command.new('true')
+
+ result = pipeline.new(true_command, true_command).run_pipeline!
+
+ expect(result).to be_a(Gitlab::Backup::Cli::Shell::Pipeline::Result)
+ end
+
+ context 'with Pipeline::Status' do
+ it 'includes stderr from the executed pipeline' do
+ expected_output = 'my custom error content'
+ err_command = command.new("echo #{expected_output} > /dev/stderr")
+
+ result = pipeline.new(err_command).run_pipeline!
+
+ expect(result.stderr.chomp).to eq(expected_output)
+ end
+
+ it 'includes a list of Process::Status from the executed pipeline' do
+ true_command = command.new('true')
+
+ result = pipeline.new(true_command, true_command).run_pipeline!
+
+ expect(result.status_list).to all be_a(Process::Status)
+ expect(result.status_list).to all respond_to(:exited?, :termsig, :stopsig, :exitstatus, :success?, :pid)
+ end
+
+ it 'includes a list of Process::Status that handles exit signals' do
+ false_command = command.new('false')
+
+ result = pipeline.new(false_command, false_command).run_pipeline!
+
+ expect(result.status_list).to all satisfy { |status| !status.success? }
+ expect(result.status_list).to all satisfy { |status| status.exitstatus == 1 }
+ end
+ end
+
+ it 'accepts stdin and stdout redirection' do
+ echo_command = command.new(%(ruby -e "print 'stdin is : ' + STDIN.readline"))
+ input_r, input_w = IO.pipe
+ input_w.sync = true
+ input_w.print 'my custom content'
+ input_w.close
+
+ output_r, output_w = IO.pipe
+
+ result = pipeline.new(echo_command).run_pipeline!(input: input_r, output: output_w)
+
+ input_r.close
+ output_w.close
+ output = output_r.read
+ output_r.close
+
+ expect(result.status_list.size).to eq(1)
+ expect(result.status_list[0]).to be_success
+ expect(output).to match(/stdin is : my custom content/)
+ end
+ end
+end
--
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