Resolve "Add "What's new" menu item in top navigation"

3 files changed, 88 insertions, 8 deletions

diff --git a/lib/gitlab.rb b/lib/gitlab.rb
index 2ef54658a11..074d04fc32a 100644
--- a/lib/gitlab.rb
+++ b/lib/gitlab.rb
@@ -27,12 +27,52 @@ module Gitlab
     end
   end
 
+  def self.version_info
+    Gitlab::VersionInfo.parse(Gitlab::VERSION)
+  end
+
   COM_URL = 'https://gitlab.com'.freeze
   APP_DIRS_PATTERN = %r{^/?(app|config|ee|lib|spec|\(\w*\))}
   SUBDOMAIN_REGEX = %r{\Ahttps://[a-z0-9]+\.gitlab\.com\z}
   VERSION = File.read(root.join("VERSION")).strip.freeze
   INSTALLATION_TYPE = File.read(root.join("INSTALLATION_TYPE")).strip.freeze
 
+  def self.pre_release?
+    VERSION.include?('pre')
+  end
+
+  def self.final_release?
+    !VERSION.include?('rc') && !pre_release?
+  end
+
+  def self.minor_release
+    "#{version_info.major}.#{version_info.minor}"
+  end
+
+  def self.prev_minor_release
+    "#{version_info.major}.#{version_info.minor - 1}"
+  end
+
+  def self.prev_major_release
+    "#{version_info.major.to_i - 1}"
+  end
+
+  def self.new_major_release?
+    version_info.minor.to_i.zero?
+  end
+
+  def self.previous_release
+    if version_info.minor_version?
+      if version_info.patch_version?
+        minor_release
+      else
+        prev_minor_release
+      end
+    else
+      prev_major_release
+    end
+  end
+
   def self.com?
     # Check `gl_subdomain?` as well to keep parity with gitlab.com
     Gitlab.config.gitlab.url == COM_URL || gl_subdomain?
@@ -49,12 +89,4 @@ module Gitlab
   def self.dev_env_or_com?
     Rails.env.development? || org? || com?
   end
-
-  def self.pre_release?
-    VERSION.include?('pre')
-  end
-
-  def self.version_info
-    Gitlab::VersionInfo.parse(Gitlab::VERSION)
-  end
 end
diff --git a/lib/gitlab/release_blog_post.rb b/lib/gitlab/release_blog_post.rb
new file mode 100644
index 00000000000..639aee61464
--- /dev/null
+++ b/lib/gitlab/release_blog_post.rb
@@ -0,0 +1,40 @@
+# frozen_string_literal: true
+require 'singleton'
+
+module Gitlab
+  class ReleaseBlogPost
+    include Singleton
+
+    RELEASE_RSS_URL = 'https://about.gitlab.com/releases.xml'
+
+    def blog_post_url
+      @url ||= fetch_blog_post_url
+    end
+
+    private
+
+    def fetch_blog_post_url
+      installed_version = Gitlab.final_release? ? Gitlab.minor_release : Gitlab.previous_release
+      response = Gitlab::HTTP.get(RELEASE_RSS_URL, verify: false)
+
+      return unless response.code == 200
+
+      blog_entry = find_installed_blog_entry(response, installed_version)
+      blog_entry['id'] if blog_entry
+    end
+
+    def find_installed_blog_entry(response, installed_version)
+      response['feed']['entry'].find do |entry|
+        entry['release'] == installed_version || matches_previous_release_post(entry['release'], installed_version)
+      end
+    end
+
+    def should_match_previous_release_post?
+      Gitlab.new_major_release? && !Gitlab.final_release?
+    end
+
+    def matches_previous_release_post(rss_release_version, installed_version)
+      should_match_previous_release_post? && rss_release_version[/\d+/] == installed_version
+    end
+  end
+end
diff --git a/lib/gitlab/version_info.rb b/lib/gitlab/version_info.rb
index aa6d5310161..142ead12c08 100644
--- a/lib/gitlab/version_info.rb
+++ b/lib/gitlab/version_info.rb
@@ -20,6 +20,14 @@ module Gitlab
       @patch = patch
     end
 
+    def minor_version?
+      minor.to_i > 0
+    end
+
+    def patch_version?
+      patch.to_i > 0
+    end
+
     def <=>(other)
       return unless other.is_a? VersionInfo
       return unless valid? && other.valid?