diff options
| -rw-r--r-- | TODO.md | 1 | ||||
| -rw-r--r-- | lib/dsl.rb | 2 | ||||
| -rw-r--r-- | lib/dslkeywords/file.rb | 23 | ||||
| -rw-r--r-- | lib/dslkeywords/keyword.rb | 2 | ||||
| -rw-r--r-- | lib/dslkeywords/notify.rb | 6 | ||||
| -rw-r--r-- | lib/dslkeywords/resource.rb | 63 | ||||
| -rw-r--r-- | playground/Rakefile | 2 | ||||
| -rw-r--r-- | test/lib/dslkeywords/dependency_test.rb | 50 |
8 files changed, 125 insertions, 24 deletions
@@ -16,7 +16,6 @@ * Binary installation support (file copy from source to dest) * Local file system * scp? git? http/s? -* Object dependencies / ensuring correct order of evaluation * Manage services (start, stop, restart (subscribe)) * Manage packages (install, update, deinstall) * Fedora @@ -25,7 +25,7 @@ module RCM def initialize(reset) DSL.reset! if reset - @id = "dsl[#{@@rcm_counter += 1}]" + @id = "dsl(#{@@rcm_counter += 1})" @conds_met = true @scheduled = [] yield self if block_given? diff --git a/lib/dslkeywords/file.rb b/lib/dslkeywords/file.rb index 501b7c8..e83906e 100644 --- a/lib/dslkeywords/file.rb +++ b/lib/dslkeywords/file.rb @@ -1,13 +1,32 @@ +require 'digest' require 'erb' require 'fileutils' require_relative 'resource' module RCM + # Backup the file on change + module FileBackup + def backup!(path) + return unless ::File.exist?(path) + + backup_dir = "#{::File.dirname(path)}/.rcm" + Dir.mkdir(backup_dir) unless ::File.directory?(backup_dir) + checksum = Digest::SHA256.file(path).hexdigest + backup_path = "#{backup_dir}/#{::File.basename(path)}.#{checksum}" + return if ::File.exist?(backup_path) + + info("Backing up #{path} -> #{backup_path}") + ::File.rename(path, backup_path) + end + end + # Managing files class File < Resource attr_reader :path + include FileBackup + def initialize(path) super(path) @path = path @@ -25,6 +44,7 @@ module RCM def ensure_line(line) = @ensure_line = line def evaluate! + return unless super return evaluate_ensure_line! unless @ensure_line.nil? write_content!(real_content) @@ -44,9 +64,10 @@ module RCM def write_content!(text) create_parent_directory! debug text if option :debug - info "Creating file #{@path}" + info "Managing file #{@path}" tmp_path = "#{@path}.tmp" ::File.write(tmp_path, text) + backup!(@path) ::File.rename(tmp_path, @path) end diff --git a/lib/dslkeywords/keyword.rb b/lib/dslkeywords/keyword.rb index 2696e41..2dfff91 100644 --- a/lib/dslkeywords/keyword.rb +++ b/lib/dslkeywords/keyword.rb @@ -9,7 +9,7 @@ module RCM include Options include Log - def initialize(name) = @id = "#{self.class.to_s.sub('RCM::', '').downcase}['#{name}']" + def initialize(name) = @id = "#{self.class.to_s.sub('RCM::', '').downcase}('#{name}')" def to_s = @id end end diff --git a/lib/dslkeywords/notify.rb b/lib/dslkeywords/notify.rb index 602d216..e1d8a3d 100644 --- a/lib/dslkeywords/notify.rb +++ b/lib/dslkeywords/notify.rb @@ -15,7 +15,11 @@ module RCM @message = msg unless msg.nil? end - def evaluate! = puts "#{id} => #{@message}" + def evaluate! + return unless super + + puts "#{id} => #{@message}" + end end # Add notify keyword to the DSL diff --git a/lib/dslkeywords/resource.rb b/lib/dslkeywords/resource.rb index c9098d4..f665a50 100644 --- a/lib/dslkeywords/resource.rb +++ b/lib/dslkeywords/resource.rb @@ -7,41 +7,80 @@ module RCM module ResourceDependencies def initialize(...) super(...) + @depends_on = Set.new @valid_resources = Set.new ObjectSpace.each_object(Class).each do |klass| @valid_resources << klass.to_s.sub('RCM::', '').downcase.to_sym if klass < Resource end end - # Only to have the resourcename[id] syntax available in the DSL - class SyntaxSugar - def initialize(name) = @name = name - def [](other) = "#{@name}['#{other}']" - end - class NoSuchResourceType < StandardError; end - def method_missing(method_name) + def method_missing(method_name, *args) raise NoSuchResourceType, "No such resource type: #{method_name}" unless @valid_resources.include?(method_name) - SyntaxSugar.new(method_name) + args.map { |arg| "#{method_name}('#{arg}')" } end def respond_to_missing? = true def depends_on(*others) - @dependencies = {} if @dependencies.nil? - others.each do |other| + return @depends_on if others.empty? + + others.flatten.each do |other| info "Registered dependency on #{other}" - @dependencies[other] = {} + @depends_on << other end end - def dependencies = @dependencies.nil ? [] : @dependencies + def depends_on?(*others) = others.flatten.none? { |other| !@depends_on&.include?(other) } + end + + # To resolve dependencies + module DependencyEvaluator + attr_reader :evaluated + + class DependencyLoop < StandardError; end + class UnresolvedDependency < StandardError; end + + def evaluate! + return false if @evaluated + + raise DependencyLoop, "Dependency loop detected for #{id}" if @loop_detection + + @loop_detection = true + + # Try to evaluate all dependencies recursively. + @depends_on.each.map { Resource.find(_1) }.each(&:evaluate!) + + # Raise an exception when there are still unresolved dependencies. + unresolved = @depends_on.each.map { Resource.find(_1) }.reject(&:evaluated) + raise UnresolvedDependency, "Unresolved dependencies: #{unresolved.map(&:id)}" if unresolved.count.positive? + + @loop_detection = false + @evaluated = true + end end # A resource is something concrete to be managed, e.g. a file, or a CRON job. class Resource < Keyword + include DependencyEvaluator include ResourceDependencies + + class NoSuchResourceObject < StandardError; end + + # TODO: Detect duplicate resource definition + + @@resource_find_cache = {} + + def self.find(id) + return @@resource_find_cache[id] if @@resource_find_cache.key?(id) + + klass = Object.const_get("RCM::#{id.split('(').first.capitalize}") + resource = ObjectSpace.each_object(klass).find { _1.id == id } + raise NoSuchResourceObject, "Unable to find resource #{id}" if resource.nil? + + @@resource_find_cache[id] = resource + end end end diff --git a/playground/Rakefile b/playground/Rakefile index ef53d00..35ae811 100644 --- a/playground/Rakefile +++ b/playground/Rakefile @@ -37,7 +37,7 @@ task :foo do configure do file '/tmp/foo.txt' do ensure_line 'foo' - depends_on file['/tmp/bar.txt'] + depends_on file '/tmp/bar.txt' end file '/tmp/bar.txt' do diff --git a/test/lib/dslkeywords/dependency_test.rb b/test/lib/dslkeywords/dependency_test.rb index 324a756..aeb2790 100644 --- a/test/lib/dslkeywords/dependency_test.rb +++ b/test/lib/dslkeywords/dependency_test.rb @@ -5,25 +5,63 @@ require_relative '../../../lib/dsl' class RCMDependencyTest < Minitest::Test def test_depends_on + foo = nil + bar = nil + baz = nil + configure_from_scratch do - notify 'foo' do - depends_on notify['bar'], notify['baz'] + foo = notify 'foo' do + depends_on notify 'bar', 'baz' :foo_message end - notify 'bar' + bar = notify 'bar' - notify 'baz' do - depends_on notify['bar'] + baz = notify 'baz' do + depends_on notify 'bar' :baz_message end end + + assert_equal 2, foo.depends_on.count + assert foo.depends_on?("notify('bar')", "notify('baz')") + + assert_equal 0, bar.depends_on.count + refute bar.depends_on?('foo') + + assert_equal 1, baz.depends_on.count + assert baz.depends_on?("notify('bar')") end def test_depends_on_invalid_resource assert_raises(RCM::ResourceDependencies::NoSuchResourceType) do configure_from_scratch do - notify { depends_on invalid['baz'] } + notify { depends_on invalid('baz') } + end + end + end + + def test_depends_on_non_existant_dependency + assert_raises(RCM::Resource::NoSuchResourceObject) do + configure_from_scratch do + notify { depends_on notify('nonexistant') } + end + end + end + + def test_dependency_loop + assert_raises(RCM::DependencyEvaluator::DependencyLoop) do + configure_from_scratch do + notify('loop') { depends_on notify('loop') } + end + end + end + + def test_dependency_loop_indirect + assert_raises(RCM::DependencyEvaluator::DependencyLoop) do + configure_from_scratch do + notify('loop') { depends_on notify('pool') } + notify('pool') { depends_on notify('loop') } end end end |