1 files changed, 45 insertions, 7 deletions

diff --git a/lib/gitlab/ci/config/external/mapper.rb b/lib/gitlab/ci/config/external/mapper.rb
index def3563e505..74bd927da39 100644
--- a/lib/gitlab/ci/config/external/mapper.rb
+++ b/lib/gitlab/ci/config/external/mapper.rb
@@ -5,25 +5,63 @@ module Gitlab
     class Config
       module External
         class Mapper
-          def initialize(values, project, sha)
-            @locations = Array(values.fetch(:include, []))
+          include Gitlab::Utils::StrongMemoize
+
+          FILE_CLASSES = [
+            External::File::Remote,
+            External::File::Template,
+            External::File::Local
+          ].freeze
+
+          AmbigiousSpecificationError = Class.new(StandardError)
+
+          def initialize(values, project:, sha:)
+            @locations = Array.wrap(values.fetch(:include, []))
             @project = project
             @sha = sha
           end
 
           def process
-            locations.map { |location| build_external_file(location) }
+            locations
+              .compact
+              .map(&method(:normalize_location))
+              .map(&method(:select_first_matching))
           end
 
           private
 
-          attr_reader :locations, :project, :sha
+          attr_reader :locations, :project, :sha, :user
+
+          # convert location if String to canonical form
+          def normalize_location(location)
+            if location.is_a?(String)
+              normalize_location_string(location)
+            else
+              location.deep_symbolize_keys
+            end
+          end
 
-          def build_external_file(location)
+          def normalize_location_string(location)
             if ::Gitlab::UrlSanitizer.valid?(location)
-              External::File::Remote.new(location)
+              { remote: location }
             else
-              External::File::Local.new(location, project: project, sha: sha)
+              { local: location }
+            end
+          end
+
+          def select_first_matching(location)
+            matching = FILE_CLASSES.map do |file_class|
+              file_class.new(location, context)
+            end.select(&:matching?)
+
+            raise AmbigiousSpecificationError, "Include `#{location.to_json}` needs to match exactly one accessor!" unless matching.one?
+
+            matching.first
+          end
+
+          def context
+            strong_memoize(:context) do
+              External::File::Base::Context.new(project, sha)
             end
           end
         end