Merge branch 'refactor/ci-config-move-job-entries' into 'master'

Move CI job config entries from legacy to new config

## What does this MR do?

This MR extracts jobs configuration logic from legacy CI config processor to the new code.

## What are the relevant issue numbers?

#15060

## Does this MR meet the acceptance criteria?

- Tests
  - [x] Added for this feature/bug
  - [x] All builds are passing
- [x] Conform by the [style guides](https://gitlab.com/gitlab-org/gitlab-ce/blob/master/CONTRIBUTING.md#style-guides)
- [x] Branch has no merge conflicts with `master` (if you do - rebase it please)

See merge request !5087

20 files changed, 524 insertions, 260 deletions

diff --git a/lib/ci/gitlab_ci_yaml_processor.rb b/lib/ci/gitlab_ci_yaml_processor.rb
index 83afed9f49f..a2e8bd22a52 100644
--- a/lib/ci/gitlab_ci_yaml_processor.rb
+++ b/lib/ci/gitlab_ci_yaml_processor.rb
@@ -4,21 +4,11 @@ module Ci
 
     include Gitlab::Ci::Config::Node::LegacyValidationHelpers
 
-    DEFAULT_STAGE = 'test'
-    ALLOWED_YAML_KEYS = [:before_script, :after_script, :image, :services, :types, :stages, :variables, :cache]
-    ALLOWED_JOB_KEYS = [:tags, :script, :only, :except, :type, :image, :services,
-                        :allow_failure, :type, :stage, :when, :artifacts, :cache,
-                        :dependencies, :before_script, :after_script, :variables,
-                        :environment]
-    ALLOWED_CACHE_KEYS = [:key, :untracked, :paths]
-    ALLOWED_ARTIFACTS_KEYS = [:name, :untracked, :paths, :when, :expire_in]
-
     attr_reader :path, :cache, :stages
 
     def initialize(config, path = nil)
       @ci_config = Gitlab::Ci::Config.new(config)
       @config = @ci_config.to_hash
-
       @path = path
 
       unless @ci_config.valid?
@@ -26,7 +16,6 @@ module Ci
       end
 
       initial_parsing
-      validate!
     rescue Gitlab::Ci::Config::Loader::FormatError => e
       raise ValidationError, e.message
     end
@@ -73,7 +62,7 @@ module Ci
         #  - before script should be a concatenated command
         commands: [job[:before_script] || @before_script, job[:script]].flatten.compact.join("\n"),
         tag_list: job[:tags] || [],
-        name: name,
+        name: job[:name],
         allow_failure: job[:allow_failure] || false,
         when: job[:when] || 'on_success',
         environment: job[:environment],
@@ -92,6 +81,9 @@ module Ci
     private
 
     def initial_parsing
+      ##
+      # Global config
+      #
       @before_script = @ci_config.before_script
       @image = @ci_config.image
       @after_script = @ci_config.after_script
@@ -100,34 +92,28 @@ module Ci
       @stages = @ci_config.stages
       @cache = @ci_config.cache
 
-      @jobs = {}
-
-      @config.except!(*ALLOWED_YAML_KEYS)
-      @config.each { |name, param| add_job(name, param) }
-
-      raise ValidationError, "Please define at least one job" if @jobs.none?
-    end
-
-    def add_job(name, job)
-      return if name.to_s.start_with?('.')
+      ##
+      # Jobs
+      #
+      @jobs = @ci_config.jobs
 
-      raise ValidationError, "Unknown parameter: #{name}" unless job.is_a?(Hash) && job.has_key?(:script)
+      @jobs.each do |name, job|
+        # logical validation for job
 
-      stage = job[:stage] || job[:type] || DEFAULT_STAGE
-      @jobs[name] = { stage: stage }.merge(job)
+        validate_job_stage!(name, job)
+        validate_job_dependencies!(name, job)
+      end
     end
 
     def yaml_variables(name)
-      variables = global_variables.merge(job_variables(name))
+      variables = (@variables || {})
+        .merge(job_variables(name))
+
       variables.map do |key, value|
         { key: key, value: value, public: true }
       end
     end
 
-    def global_variables
-      @variables || {}
-    end
-
     def job_variables(name)
       job = @jobs[name.to_sym]
       return {} unless job
@@ -135,154 +121,16 @@ module Ci
       job[:variables] || {}
     end
 
-    def validate!
-      @jobs.each do |name, job|
-        validate_job!(name, job)
-      end
-
-      true
-    end
-
-    def validate_job!(name, job)
-      validate_job_name!(name)
-      validate_job_keys!(name, job)
-      validate_job_types!(name, job)
-      validate_job_script!(name, job)
-
-      validate_job_stage!(name, job) if job[:stage]
-      validate_job_variables!(name, job) if job[:variables]
-      validate_job_cache!(name, job) if job[:cache]
-      validate_job_artifacts!(name, job) if job[:artifacts]
-      validate_job_dependencies!(name, job) if job[:dependencies]
-    end
-
-    def validate_job_name!(name)
-      if name.blank? || !validate_string(name)
-        raise ValidationError, "job name should be non-empty string"
-      end
-    end
-
-    def validate_job_keys!(name, job)
-      job.keys.each do |key|
-        unless ALLOWED_JOB_KEYS.include? key
-          raise ValidationError, "#{name} job: unknown parameter #{key}"
-        end
-      end
-    end
-
-    def validate_job_types!(name, job)
-      if job[:image] && !validate_string(job[:image])
-        raise ValidationError, "#{name} job: image should be a string"
-      end
-
-      if job[:services] && !validate_array_of_strings(job[:services])
-        raise ValidationError, "#{name} job: services should be an array of strings"
-      end
-
-      if job[:tags] && !validate_array_of_strings(job[:tags])
-        raise ValidationError, "#{name} job: tags parameter should be an array of strings"
-      end
-
-      if job[:only] && !validate_array_of_strings_or_regexps(job[:only])
-        raise ValidationError, "#{name} job: only parameter should be an array of strings or regexps"
-      end
-
-      if job[:except] && !validate_array_of_strings_or_regexps(job[:except])
-        raise ValidationError, "#{name} job: except parameter should be an array of strings or regexps"
-      end
-
-      if job[:allow_failure] && !validate_boolean(job[:allow_failure])
-        raise ValidationError, "#{name} job: allow_failure parameter should be an boolean"
-      end
-
-      if job[:when] && !job[:when].in?(%w[on_success on_failure always manual])
-        raise ValidationError, "#{name} job: when parameter should be on_success, on_failure, always or manual"
-      end
-
-      if job[:environment] && !validate_environment(job[:environment])
-        raise ValidationError, "#{name} job: environment parameter #{Gitlab::Regex.environment_name_regex_message}"
-      end
-    end
-
-    def validate_job_script!(name, job)
-      if !validate_string(job[:script]) && !validate_array_of_strings(job[:script])
-        raise ValidationError, "#{name} job: script should be a string or an array of a strings"
-      end
-
-      if job[:before_script] && !validate_array_of_strings(job[:before_script])
-        raise ValidationError, "#{name} job: before_script should be an array of strings"
-      end
-
-      if job[:after_script] && !validate_array_of_strings(job[:after_script])
-        raise ValidationError, "#{name} job: after_script should be an array of strings"
-      end
-    end
-
     def validate_job_stage!(name, job)
+      return unless job[:stage]
+
       unless job[:stage].is_a?(String) && job[:stage].in?(@stages)
         raise ValidationError, "#{name} job: stage parameter should be #{@stages.join(", ")}"
       end
     end
 
-    def validate_job_variables!(name, job)
-      unless validate_variables(job[:variables])
-        raise ValidationError,
-          "#{name} job: variables should be a map of key-value strings"
-      end
-    end
-
-    def validate_job_cache!(name, job)
-      job[:cache].keys.each do |key|
-        unless ALLOWED_CACHE_KEYS.include? key
-          raise ValidationError, "#{name} job: cache unknown parameter #{key}"
-        end
-      end
-
-      if job[:cache][:key] && !validate_string(job[:cache][:key])
-        raise ValidationError, "#{name} job: cache:key parameter should be a string"
-      end
-
-      if job[:cache][:untracked] && !validate_boolean(job[:cache][:untracked])
-        raise ValidationError, "#{name} job: cache:untracked parameter should be an boolean"
-      end
-
-      if job[:cache][:paths] && !validate_array_of_strings(job[:cache][:paths])
-        raise ValidationError, "#{name} job: cache:paths parameter should be an array of strings"
-      end
-    end
-
-    def validate_job_artifacts!(name, job)
-      job[:artifacts].keys.each do |key|
-        unless ALLOWED_ARTIFACTS_KEYS.include? key
-          raise ValidationError, "#{name} job: artifacts unknown parameter #{key}"
-        end
-      end
-
-      if job[:artifacts][:name] && !validate_string(job[:artifacts][:name])
-        raise ValidationError, "#{name} job: artifacts:name parameter should be a string"
-      end
-
-      if job[:artifacts][:untracked] && !validate_boolean(job[:artifacts][:untracked])
-        raise ValidationError, "#{name} job: artifacts:untracked parameter should be an boolean"
-      end
-
-      if job[:artifacts][:paths] && !validate_array_of_strings(job[:artifacts][:paths])
-        raise ValidationError, "#{name} job: artifacts:paths parameter should be an array of strings"
-      end
-
-      if job[:artifacts][:when] && !job[:artifacts][:when].in?(%w[on_success on_failure always])
-        raise ValidationError, "#{name} job: artifacts:when parameter should be on_success, on_failure or always"
-      end
-
-      if job[:artifacts][:expire_in] && !validate_duration(job[:artifacts][:expire_in])
-        raise ValidationError, "#{name} job: artifacts:expire_in parameter should be a duration"
-      end
-    end
-
     def validate_job_dependencies!(name, job)
-      unless validate_array_of_strings(job[:dependencies])
-        raise ValidationError, "#{name} job: dependencies parameter should be an array of strings"
-      end
+      return unless job[:dependencies]
 
       stage_index = @stages.index(job[:stage])
 
diff --git a/lib/gitlab/ci/config.rb b/lib/gitlab/ci/config.rb
index e6cc1529760..ae82c0db3f1 100644
--- a/lib/gitlab/ci/config.rb
+++ b/lib/gitlab/ci/config.rb
@@ -8,7 +8,7 @@ module Gitlab
       # Temporary delegations that should be removed after refactoring
       #
       delegate :before_script, :image, :services, :after_script, :variables,
-               :stages, :cache, to: :@global
+               :stages, :cache, :jobs, to: :@global
 
       def initialize(config)
         @config = Loader.new(config).load!
diff --git a/lib/gitlab/ci/config/node/artifacts.rb b/lib/gitlab/ci/config/node/artifacts.rb
new file mode 100644
index 00000000000..844bd2fe998
--- /dev/null
+++ b/lib/gitlab/ci/config/node/artifacts.rb
@@ -0,0 +1,35 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a configuration of job artifacts.
+        #
+        class Artifacts < Entry
+          include Validatable
+          include Attributable
+
+          ALLOWED_KEYS = %i[name untracked paths when expire_in]
+
+          attributes ALLOWED_KEYS
+
+          validations do
+            validates :config, type: Hash
+            validates :config, allowed_keys: ALLOWED_KEYS
+
+            with_options allow_nil: true do
+              validates :name, type: String
+              validates :untracked, boolean: true
+              validates :paths, array_of_strings: true
+              validates :when,
+                inclusion: { in: %w[on_success on_failure always],
+                             message: 'should be on_success, on_failure ' \
+                                      'or always' }
+              validates :expire_in, duration: true
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/attributable.rb b/lib/gitlab/ci/config/node/attributable.rb
new file mode 100644
index 00000000000..221b666f9f6
--- /dev/null
+++ b/lib/gitlab/ci/config/node/attributable.rb
@@ -0,0 +1,23 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        module Attributable
+          extend ActiveSupport::Concern
+
+          class_methods do
+            def attributes(*attributes)
+              attributes.flatten.each do |attribute|
+                define_method(attribute) do
+                  return unless config.is_a?(Hash)
+
+                  config[attribute]
+                end
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/cache.rb b/lib/gitlab/ci/config/node/cache.rb
index cdf8ba2e35d..b4bda2841ac 100644
--- a/lib/gitlab/ci/config/node/cache.rb
+++ b/lib/gitlab/ci/config/node/cache.rb
@@ -8,6 +8,12 @@ module Gitlab
         class Cache < Entry
           include Configurable
 
+          ALLOWED_KEYS = %i[key untracked paths]
+
+          validations do
+            validates :config, allowed_keys: ALLOWED_KEYS
+          end
+
           node :key, Node::Key,
             description: 'Cache key used to define a cache affinity.'
 
@@ -16,10 +22,6 @@ module Gitlab
 
           node :paths, Node::Paths,
             description: 'Specify which paths should be cached across builds.'
-
-          validations do
-            validates :config, allowed_keys: true
-          end
         end
       end
     end
diff --git a/lib/gitlab/ci/config/node/commands.rb b/lib/gitlab/ci/config/node/commands.rb
new file mode 100644
index 00000000000..d7657ae314b
--- /dev/null
+++ b/lib/gitlab/ci/config/node/commands.rb
@@ -0,0 +1,33 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a job script.
+        #
+        class Commands < Entry
+          include Validatable
+
+          validations do
+            include LegacyValidationHelpers
+
+            validate do
+              unless string_or_array_of_strings?(config)
+                errors.add(:config,
+                           'should be a string or an array of strings')
+              end
+            end
+
+            def string_or_array_of_strings?(field)
+              validate_string(field) || validate_array_of_strings(field)
+            end
+          end
+
+          def value
+            Array(@config)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/configurable.rb b/lib/gitlab/ci/config/node/configurable.rb
index 37936fc8242..aedc28fe1d0 100644
--- a/lib/gitlab/ci/config/node/configurable.rb
+++ b/lib/gitlab/ci/config/node/configurable.rb
@@ -25,10 +25,14 @@ module Gitlab
 
           private
 
-          def create_node(key, factory)
-            factory.with(value: @config[key], key: key, parent: self)
+          def compose!
+            self.class.nodes.each do |key, factory|
+              factory
+                .value(@config[key])
+                .with(key: key, parent: self)
 
-            factory.create!
+              @entries[key] = factory.create!
+            end
           end
 
           class_methods do
@@ -38,22 +42,23 @@ module Gitlab
 
             private
 
-            def node(symbol, entry_class, metadata)
-              factory = Node::Factory.new(entry_class)
+            def node(key, node, metadata)
+              factory = Node::Factory.new(node)
                 .with(description: metadata[:description])
 
-              (@nodes ||= {}).merge!(symbol.to_sym => factory)
+              (@nodes ||= {}).merge!(key.to_sym => factory)
             end
 
             def helpers(*nodes)
               nodes.each do |symbol|
                 define_method("#{symbol}_defined?") do
-                  @nodes[symbol].try(:defined?)
+                  @entries[symbol].specified? if @entries[symbol]
                 end
 
                 define_method("#{symbol}_value") do
-                  raise Entry::InvalidError unless valid?
-                  @nodes[symbol].try(:value)
+                  return unless @entries[symbol] && @entries[symbol].valid?
+
+                  @entries[symbol].value
                 end
 
                 alias_method symbol.to_sym, "#{symbol}_value".to_sym
diff --git a/lib/gitlab/ci/config/node/entry.rb b/lib/gitlab/ci/config/node/entry.rb
index 9e79e170a4f..0c782c422b5 100644
--- a/lib/gitlab/ci/config/node/entry.rb
+++ b/lib/gitlab/ci/config/node/entry.rb
@@ -8,30 +8,31 @@ module Gitlab
         class Entry
           class InvalidError < StandardError; end
 
-          attr_reader :config
+          attr_reader :config, :metadata
           attr_accessor :key, :parent, :description
 
-          def initialize(config)
+          def initialize(config, **metadata)
             @config = config
-            @nodes = {}
+            @metadata = metadata
+            @entries = {}
+
             @validator = self.class.validator.new(self)
-            @validator.validate
+            @validator.validate(:new)
           end
 
           def process!
-            return if leaf?
             return unless valid?
 
             compose!
-            process_nodes!
+            descendants.each(&:process!)
           end
 
-          def nodes
-            @nodes.values
+          def leaf?
+            @entries.none?
           end
 
-          def leaf?
-            self.class.nodes.none?
+          def descendants
+            @entries.values
           end
 
           def ancestors
@@ -43,27 +44,30 @@ module Gitlab
           end
 
           def errors
-            @validator.messages + nodes.flat_map(&:errors)
+            @validator.messages + descendants.flat_map(&:errors)
           end
 
           def value
             if leaf?
               @config
             else
-              defined = @nodes.select { |_key, value| value.defined? }
-              Hash[defined.map { |key, node| [key, node.value] }]
+              meaningful = @entries.select do |_key, value|
+                value.specified? && value.relevant?
+              end
+
+              Hash[meaningful.map { |key, entry| [key, entry.value] }]
             end
           end
 
-          def defined?
+          def specified?
             true
           end
 
-          def self.default
+          def relevant?
+            true
           end
 
-          def self.nodes
-            {}
+          def self.default
           end
 
           def self.validator
@@ -73,17 +77,6 @@ module Gitlab
           private
 
           def compose!
-            self.class.nodes.each do |key, essence|
-              @nodes[key] = create_node(key, essence)
-            end
-          end
-
-          def process_nodes!
-            nodes.each(&:process!)
-          end
-
-          def create_node(key, essence)
-            raise NotImplementedError
           end
         end
       end
diff --git a/lib/gitlab/ci/config/node/factory.rb b/lib/gitlab/ci/config/node/factory.rb
index 5919a283283..707b052e6a8 100644
--- a/lib/gitlab/ci/config/node/factory.rb
+++ b/lib/gitlab/ci/config/node/factory.rb
@@ -10,35 +10,60 @@ module Gitlab
 
           def initialize(node)
             @node = node
+            @metadata = {}
             @attributes = {}
           end
 
+          def value(value)
+            @value = value
+            self
+          end
+
+          def metadata(metadata)
+            @metadata.merge!(metadata)
+            self
+          end
+
           def with(attributes)
             @attributes.merge!(attributes)
             self
           end
 
           def create!
-            raise InvalidFactory unless @attributes.has_key?(:value)
+            raise InvalidFactory unless defined?(@value)
 
-            fabricate.tap do |entry|
-              entry.key = @attributes[:key]
-              entry.parent = @attributes[:parent]
-              entry.description = @attributes[:description]
+            ##
+            # We assume that unspecified entry is undefined.
+            # See issue #18775.
+            #
+            if @value.nil?
+              Node::Undefined.new(
+                fabricate_undefined
+              )
+            else
+              fabricate(@node, @value)
             end
           end
 
           private
 
-          def fabricate
+          def fabricate_undefined
             ##
-            # We assume that unspecified entry is undefined.
-            # See issue #18775.
+            # If node has a default value we fabricate concrete node
+            # with default value.
             #
-            if @attributes[:value].nil?
-              Node::Undefined.new(@node)
+            if @node.default.nil?
+              fabricate(Node::Null)
             else
-              @node.new(@attributes[:value])
+              fabricate(@node, @node.default)
+            end
+          end
+
+          def fabricate(node, value = nil)
+            node.new(value, @metadata).tap do |entry|
+              entry.key = @attributes[:key]
+              entry.parent = @attributes[:parent]
+              entry.description = @attributes[:description]
             end
           end
         end
diff --git a/lib/gitlab/ci/config/node/global.rb b/lib/gitlab/ci/config/node/global.rb
index f92e1eccbcf..ccd539fb003 100644
--- a/lib/gitlab/ci/config/node/global.rb
+++ b/lib/gitlab/ci/config/node/global.rb
@@ -34,10 +34,36 @@ module Gitlab
             description: 'Configure caching between build jobs.'
 
           helpers :before_script, :image, :services, :after_script,
-                  :variables, :stages, :types, :cache
+                  :variables, :stages, :types, :cache, :jobs
 
-          def stages
-            stages_defined? ? stages_value : types_value
+          private
+
+          def compose!
+            super
+
+            compose_jobs!
+            compose_deprecated_entries!
+          end
+
+          def compose_jobs!
+            factory = Node::Factory.new(Node::Jobs)
+              .value(@config.except(*self.class.nodes.keys))
+              .with(key: :jobs, parent: self,
+                    description: 'Jobs definition for this pipeline')
+
+            @entries[:jobs] = factory.create!
+          end
+
+          def compose_deprecated_entries!
+            ##
+            # Deprecated `:types` key workaround - if types are defined and
+            # stages are not defined we use types definition as stages.
+            #
+            if types_defined? && !stages_defined?
+              @entries[:stages] = @entries[:types]
+            end
+
+            @entries.delete(:types)
           end
         end
       end
diff --git a/lib/gitlab/ci/config/node/hidden_job.rb b/lib/gitlab/ci/config/node/hidden_job.rb
new file mode 100644
index 00000000000..073044b66f8
--- /dev/null
+++ b/lib/gitlab/ci/config/node/hidden_job.rb
@@ -0,0 +1,23 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a hidden CI/CD job.
+        #
+        class HiddenJob < Entry
+          include Validatable
+
+          validations do
+            validates :config, type: Hash
+            validates :config, presence: true
+          end
+
+          def relevant?
+            false
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/job.rb b/lib/gitlab/ci/config/node/job.rb
new file mode 100644
index 00000000000..e84737acbb9
--- /dev/null
+++ b/lib/gitlab/ci/config/node/job.rb
@@ -0,0 +1,123 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a concrete CI/CD job.
+        #
+        class Job < Entry
+          include Configurable
+          include Attributable
+
+          ALLOWED_KEYS = %i[tags script only except type image services allow_failure
+                            type stage when artifacts cache dependencies before_script
+                            after_script variables environment]
+
+          attributes :tags, :allow_failure, :when, :environment, :dependencies
+
+          validations do
+            validates :config, allowed_keys: ALLOWED_KEYS
+
+            validates :config, presence: true
+            validates :name, presence: true
+            validates :name, type: Symbol
+
+            with_options allow_nil: true do
+              validates :tags, array_of_strings: true
+              validates :allow_failure, boolean: true
+              validates :when,
+                inclusion: { in: %w[on_success on_failure always manual],
+                             message: 'should be on_success, on_failure, ' \
+                                      'always or manual' }
+              validates :environment,
+                type: {
+                  with: String,
+                  message: Gitlab::Regex.environment_name_regex_message }
+              validates :environment,
+                format: {
+                  with: Gitlab::Regex.environment_name_regex,
+                  message: Gitlab::Regex.environment_name_regex_message }
+
+              validates :dependencies, array_of_strings: true
+            end
+          end
+
+          node :before_script, Script,
+            description: 'Global before script overridden in this job.'
+
+          node :script, Commands,
+            description: 'Commands that will be executed in this job.'
+
+          node :stage, Stage,
+            description: 'Pipeline stage this job will be executed into.'
+
+          node :type, Stage,
+            description: 'Deprecated: stage this job will be executed into.'
+
+          node :after_script, Script,
+            description: 'Commands that will be executed when finishing job.'
+
+          node :cache, Cache,
+            description: 'Cache definition for this job.'
+
+          node :image, Image,
+            description: 'Image that will be used to execute this job.'
+
+          node :services, Services,
+            description: 'Services that will be used to execute this job.'
+
+          node :only, Trigger,
+            description: 'Refs policy this job will be executed for.'
+
+          node :except, Trigger,
+            description: 'Refs policy this job will be executed for.'
+
+          node :variables, Variables,
+            description: 'Environment variables available for this job.'
+
+          node :artifacts, Artifacts,
+            description: 'Artifacts configuration for this job.'
+
+          helpers :before_script, :script, :stage, :type, :after_script,
+                  :cache, :image, :services, :only, :except, :variables,
+                  :artifacts
+
+          def name
+            @metadata[:name]
+          end
+
+          def value
+            @config.merge(to_hash.compact)
+          end
+
+          private
+
+          def to_hash
+            { name: name,
+              before_script: before_script,
+              script: script,
+              image: image,
+              services: services,
+              stage: stage,
+              cache: cache,
+              only: only,
+              except: except,
+              variables: variables_defined? ? variables : nil,
+              artifacts: artifacts,
+              after_script: after_script }
+          end
+
+          def compose!
+            super
+
+            if type_defined? && !stage_defined?
+              @entries[:stage] = @entries[:type]
+            end
+
+            @entries.delete(:type)
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/jobs.rb b/lib/gitlab/ci/config/node/jobs.rb
new file mode 100644
index 00000000000..51683c82ceb
--- /dev/null
+++ b/lib/gitlab/ci/config/node/jobs.rb
@@ -0,0 +1,48 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a set of jobs.
+        #
+        class Jobs < Entry
+          include Validatable
+
+          validations do
+            validates :config, type: Hash
+
+            validate do
+              unless has_visible_job?
+                errors.add(:config, 'should contain at least one visible job')
+              end
+            end
+
+            def has_visible_job?
+              config.any? { |name, _| !hidden?(name) }
+            end
+          end
+
+          def hidden?(name)
+            name.to_s.start_with?('.')
+          end
+
+          private
+
+          def compose!
+            @config.each do |name, config|
+              node = hidden?(name) ? Node::HiddenJob : Node::Job
+
+              factory = Node::Factory.new(node)
+                .value(config || {})
+                .metadata(name: name)
+                .with(key: name, parent: self,
+                      description: "#{name} job definition.")
+
+              @entries[name] = factory.create!
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/legacy_validation_helpers.rb b/lib/gitlab/ci/config/node/legacy_validation_helpers.rb
index 4d9a508796a..0c291efe6a5 100644
--- a/lib/gitlab/ci/config/node/legacy_validation_helpers.rb
+++ b/lib/gitlab/ci/config/node/legacy_validation_helpers.rb
@@ -41,10 +41,6 @@ module Gitlab
             false
           end
 
-          def validate_environment(value)
-            value.is_a?(String) && value =~ Gitlab::Regex.environment_name_regex
-          end
-
           def validate_boolean(value)
             value.in?([true, false])
           end
diff --git a/lib/gitlab/ci/config/node/null.rb b/lib/gitlab/ci/config/node/null.rb
new file mode 100644
index 00000000000..88a5f53f13c
--- /dev/null
+++ b/lib/gitlab/ci/config/node/null.rb
@@ -0,0 +1,34 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # This class represents an undefined node.
+        #
+        # Implements the Null Object pattern.
+        #
+        class Null < Entry
+          def value
+            nil
+          end
+
+          def valid?
+            true
+          end
+
+          def errors
+            []
+          end
+
+          def specified?
+            false
+          end
+
+          def relevant?
+            false
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/stage.rb b/lib/gitlab/ci/config/node/stage.rb
new file mode 100644
index 00000000000..cbc97641f5a
--- /dev/null
+++ b/lib/gitlab/ci/config/node/stage.rb
@@ -0,0 +1,22 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a stage for a job.
+        #
+        class Stage < Entry
+          include Validatable
+
+          validations do
+            validates :config, type: String
+          end
+
+          def self.default
+            'test'
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/trigger.rb b/lib/gitlab/ci/config/node/trigger.rb
new file mode 100644
index 00000000000..d8b31975088
--- /dev/null
+++ b/lib/gitlab/ci/config/node/trigger.rb
@@ -0,0 +1,26 @@
+module Gitlab
+  module Ci
+    class Config
+      module Node
+        ##
+        # Entry that represents a trigger policy for the job.
+        #
+        class Trigger < Entry
+          include Validatable
+
+          validations do
+            include LegacyValidationHelpers
+
+            validate :array_of_strings_or_regexps
+
+            def array_of_strings_or_regexps
+              unless validate_array_of_strings_or_regexps(config)
+                errors.add(:config, 'should be an array of strings or regexps')
+              end
+            end
+          end
+        end
+      end
+    end
+  end
+end
diff --git a/lib/gitlab/ci/config/node/undefined.rb b/lib/gitlab/ci/config/node/undefined.rb
index 699605e1e3a..45fef8c3ae5 100644
--- a/lib/gitlab/ci/config/node/undefined.rb
+++ b/lib/gitlab/ci/config/node/undefined.rb
@@ -3,24 +3,13 @@ module Gitlab
     class Config
       module Node
         ##
-        # This class represents an undefined entry node.
+        # This class represents an unspecified entry node.
         #
-        # It takes original entry class as configuration and returns default
-        # value of original entry as self value.
+        # It decorates original entry adding method that indicates it is
+        # unspecified.
         #
-        #
-        class Undefined < Entry
-          include Validatable
-
-          validations do
-            validates :config, type: Class
-          end
-
-          def value
-            @config.default
-          end
-
-          def defined?
+        class Undefined < SimpleDelegator
+          def specified?
             false
           end
         end
diff --git a/lib/gitlab/ci/config/node/validator.rb b/lib/gitlab/ci/config/node/validator.rb
index 758a6cf4356..43c7e102b50 100644
--- a/lib/gitlab/ci/config/node/validator.rb
+++ b/lib/gitlab/ci/config/node/validator.rb
@@ -21,18 +21,19 @@ module Gitlab
             'Validator'
           end
 
-          def unknown_keys
-            return [] unless config.is_a?(Hash)
-
-            config.keys - @node.class.nodes.keys
-          end
-
           private
 
           def location
             predecessors = ancestors.map(&:key).compact
-            current = key || @node.class.name.demodulize.underscore
-            predecessors.append(current).join(':')
+            predecessors.append(key_name).join(':')
+          end
+
+          def key_name
+            if key.blank?
+              @node.class.name.demodulize.underscore.humanize
+            else
+              key
+            end
           end
         end
       end
diff --git a/lib/gitlab/ci/config/node/validators.rb b/lib/gitlab/ci/config/node/validators.rb
index 7b2f57990b5..e20908ad3cb 100644
--- a/lib/gitlab/ci/config/node/validators.rb
+++ b/lib/gitlab/ci/config/node/validators.rb
@@ -5,10 +5,11 @@ module Gitlab
         module Validators
           class AllowedKeysValidator < ActiveModel::EachValidator
             def validate_each(record, attribute, value)
-              if record.unknown_keys.any?
-                unknown_list = record.unknown_keys.join(', ')
-                record.errors.add(:config,
-                                  "contains unknown keys: #{unknown_list}")
+              unknown_keys = record.config.try(:keys).to_a - options[:in]
+
+              if unknown_keys.any?
+                record.errors.add(:config, 'contains unknown keys: ' +
+                                            unknown_keys.join(', '))
               end
             end
           end
@@ -33,6 +34,16 @@ module Gitlab
             end
           end
 
+          class DurationValidator < ActiveModel::EachValidator
+            include LegacyValidationHelpers
+
+            def validate_each(record, attribute, value)
+              unless validate_duration(value)
+                record.errors.add(attribute, 'should be a duration')
+              end
+            end
+          end
+
           class KeyValidator < ActiveModel::EachValidator
             include LegacyValidationHelpers
 
@@ -49,7 +60,8 @@ module Gitlab
               raise unless type.is_a?(Class)
 
               unless value.is_a?(type)
-                record.errors.add(attribute, "should be a #{type.name}")
+                message = options[:message] || "should be a #{type.name}"
+                record.errors.add(attribute, message)
               end
             end
           end