dockerfile: create stub file with frontmatter

_config.yml

@@ -179,6 +179,6 @@ fetch-remote:
     default_branch: "master"
     ref: "master"
     paths:
-      - dest: "engine/reference/builder.md"
+      - dest: "_includes/dockerfile/reference.md"
         src:
           - "frontend/dockerfile/docs/reference.md"

_plugins/include_remote.rb

@@ -0,0 +1,54 @@
+module Jekyll
+  class IncludeRemoteTag < Liquid::Tag
+    def initialize(tag_name, params, tokens)
+      @page, @line_start, @line_end = params.split
+      @line_start, @line_end = resolve_line_numbers(@line_start, @line_end)
+      super
+    end
+
+    def render(context)
+      site = context.registers[:site]
+      page = context.registers[:page]
+
+      beginning_time = Time.now
+      Jekyll.logger.info "Starting plugin include_remote.rb..."
+
+      if context[@page.strip]
+        @page = context[@page.strip]
+      end
+
+      inc = File.join("_includes", @page)
+      Jekyll.logger.info "  Inject #{inc} to #{page['path']}"
+
+      lines = File.readlines(inc)[@line_start..@line_end]
+
+      site.config['defaults'].each do |default|
+        if default['scope']['path'] == inc
+          page['edit_url'] = default['values']['edit_url']
+          page['issue_url'] = default['values']['issue_url']
+          Jekyll.logger.info "    edit_url:  #{page['edit_url']}"
+          Jekyll.logger.info "    issue_url: #{page['issue_url']}"
+          break
+        end
+      end
+
+      end_time = Time.now
+      Jekyll.logger.info "done in #{(end_time - beginning_time)} seconds"
+
+      lines.join
+    end
+
+    def resolve_line_numbers(first, last)
+      if first.nil? && last.nil?
+        first = 0
+        last  = -1
+      elsif last.nil?
+        last = first
+      end
+      [first.to_i, last.to_i]
+    end
+  end
+
+end
+
+Liquid::Template.register_tag('include_remote', Jekyll::IncludeRemoteTag)

engine/reference/builder.md

@@ -0,0 +1,10 @@
+---
+title: Dockerfile reference
+description: "Dockerfiles use a simple DSL which allows you to automate the steps you would normally manually take to create an image."
+keywords: build, dockerfile, reference
+toc_max: 3
+redirect_from:
+- /reference/builder/
+---
+
+{% include_remote dockerfile/reference.md 2 -1 -%}