Backport(v6): Add gemfile:update task to bump version in Gemfile (#950)

fluent-package/Rakefile

@@ -366,6 +366,22 @@ class UpdateLockfileTask
         end
       end
     end
+
+    namespace :gemfile do
+      desc "Update Gemfile"
+      task :update do
+        require_relative '../lib/update-gems'
+        cd gemfile_dir do
+          options = {
+            lts: !!ENV['LTS'],
+            replace: true,
+            gemfile: 'Gemfile'
+          }
+          checker = GemfileUpdateChecker.new(options)
+          checker.run
+        end
+      end
+    end
   end
 end
 

lib/update-gems.rb

@@ -0,0 +1,104 @@
+#
+# Utility to update fluent-package-builder/fluent-package/Gemfile
+#
+
+require 'optparse'
+require 'open-uri'
+require 'json'
+require 'fileutils'
+begin
+  require 'pastel'
+rescue LoadError
+  puts "Prerequisite:\n\tgem install pastel"
+  exit 1
+end
+
+options = {
+  lts: false,
+  replace: true,
+  gemfile: "Gemfile"
+}
+
+class GemfileUpdateChecker
+  def initialize(options)
+    @options = options
+    @gemfile_path = options[:gemfile]
+    @new_gemfile_path = @gemfile_path + ".new"
+    @pastel = Pastel.new
+    @freeze_in_lts = %w(oj)
+  end
+
+  def fetch_latest_version(gem, version)
+    base_version = version.split(".")[0..-2].join(".")
+    latest_version = version
+    message = ""
+    URI.open("https://rubygems.org/api/v1/gems/#{gem}.json") do |request|
+      fetched_version = JSON.parse(request.read)["version"]
+      if @options[:lts]
+        if Gem::Version.new(fetched_version) < Gem::Version.new("#{base_version.succ}")
+          if @freeze_in_lts.include?(gem)
+            message = @pastel.red.on_black ( "WARN: skip even though teeny update #{gem} #{fetched_version} for LTS" )
+          else
+            latest_version = fetched_version
+          end
+        else
+          message = @pastel.yellow.on_black ( "WARN: skip #{gem} #{fetched_version} for LTS" )
+        end
+      else
+        latest_version = fetched_version
+      end
+    end
+    [latest_version, message]
+  end
+
+  def show_latest_version(gem, version, latest_version, appendix = "")
+    if version != latest_version
+      puts "GEM: #{gem} #{version} => #{@pastel.magenta.on_black( latest_version )} #{appendix}"
+    else
+      puts "GEM: #{gem} #{latest_version} #{appendix}"
+    end
+  end
+
+  def generate_updated_gemfile
+    contents = ""
+    File.open(@gemfile_path, "r") do |gemfile|
+      gemfile.readlines.each do |line|
+        if line.start_with?("gem")
+          if line =~ /^gem "(.+)", "(.+)"(.*)/
+            plugin=$1
+            version=$2
+            rest=$3
+            latest_version, warning = fetch_latest_version(plugin, version)
+            show_latest_version(plugin, version, latest_version, warning)
+            contents << "gem \"#{plugin}\", \"#{latest_version}\"#{rest}\n"
+          elsif line =~ /^gem "(.+)", '(.+)'/
+            plugin=$1
+            version=$2
+            latest_version, warning = fetch_latest_version(plugin, version)
+            show_latest_version(plugin, version, latest_version, warning)
+            contents << "gem \"#{plugin}\", \"#{latest_version}\"\n"
+          else
+            contents << line
+          end
+        else
+          contents << line
+        end
+      end
+    end
+    contents
+  end
+
+  def run
+    File.open(@new_gemfile_path, "w+") do |gemfile|
+      contents = generate_updated_gemfile
+      gemfile.puts(contents)
+      puts "#{@new_gemfile_path} was generated successfully"
+    end
+    if @options[:replace]
+      FileUtils.cp(@new_gemfile_path, @gemfile_path)
+      puts "#{@gemfile_path} was replaced with #{@new_gemfile_path} successfully"
+    else
+      puts "#{@gemfile_path} was not replaced with #{@new_gemfile_path}"
+    end
+  end
+end