chore(ui): display branch in footer if present

app/helpers/application_helper.rb

@@ -100,4 +100,11 @@ module ApplicationHelper
     end.html_safe
   end
 
+  def postal_version_string
+    string = Postal.version
+    string += " (#{Postal.branch})" if Postal.branch &&
+                                       Postal.branch != "main"
+    string
+  end
+
 end

app/views/layouts/application.html.haml

@@ -55,6 +55,8 @@
         %footer.siteContent__footer
           %ul.footer__links
             %li.footer__name
-              Powered by #{link_to "Postal", "https://postalserver.io", target: '_blank'} #{Postal.version}.
+              Powered by
+              #{link_to "Postal", "https://postalserver.io", target: '_blank'}
+              #{postal_version_string}
             %li= link_to "Documentation", "https://docs.postalserver.io", target: '_blank'
             %li= link_to "Ask for help", "https://discussions.postalserver.io", target: '_blank'

lib/postal/config.rb

@@ -153,6 +153,18 @@ module Postal
       ActiveRecord::Base.establish_connection(config.merge(pool: new_size))
     end
 
+    # Return the branch name which created this release
+    #
+    # @return [String, nil]
+    def branch
+      return @branch if instance_variable_defined?("@branch")
+
+      @branch = begin
+        path = Rails.root.join("BRANCH")
+        File.read(path).strip if File.exist?(path)
+      end
+    end
+
   end
 
   Config = initialize_config