Update styling and use Gitlab::Utils.to_boolean

app/helpers/page_layout_helper.rb

@@ -39,8 +39,9 @@ module PageLayoutHelper
   end
   def favicon
-    return 'favicon-yellow.ico' if ENV['CANARY'] == 'true'
+    return 'favicon-yellow.ico' if Gitlab::Utils.to_boolean(ENV['CANARY'])
     return 'favicon-blue.ico' if Rails.env.development?
+
     'favicon.ico'
   end

app/serializers/status_entity.rb

@@ -7,13 +7,14 @@ class StatusEntity < Grape::Entity
   expose :details_path
   expose :favicon do |status|
-    dir = 'ci_favicons'
-
-    if ENV['CANARY']
-      dir = File.join(dir, 'canary')
-    elsif Rails.env.development?
-      dir = File.join(dir, 'dev')
-    end
+    dir =
+      if Gitlab::Utils.to_boolean(ENV['CANARY'])
+        File.join('ci_favicons', 'canary')
+      elsif Rails.env.development?
+        File.join('ci_favicons', 'dev')
+      else
+        'ci_favicons'
+      end
     ActionController::Base.helpers.image_path(File.join(dir, "#{status.favicon}.ico"))
   end

changelogs/unreleased/add-canary-favicon.yml

+---
+title: Add yellow favicon to differientate canary environment
+merge_request: 12477
+author:
+type: changed

spec/helpers/page_layout_helper_spec.rb

@@ -50,6 +50,11 @@ describe PageLayoutHelper do
       allow(Rails).to receive(:env).and_return(ActiveSupport::StringInquirer.new('development'))
       expect(helper.favicon).to eq 'favicon-blue.ico'
     end
+
+    it 'has yellow favicon for canary' do
+      stub_env('CANARY', 'true')
+      expect(helper.favicon).to eq 'favicon-yellow.ico'
+    end
   end
   describe 'page_image' do

spec/serializers/status_entity_spec.rb

@@ -25,5 +25,10 @@ describe StatusEntity do
       allow(Rails.env).to receive(:development?) { true }
       expect(entity.as_json[:favicon]).to match_asset_path('/assets/ci_favicons/dev/favicon_status_success.ico')
     end
+
+    it 'contains a canavary namespaced favicon if canary env' do
+      stub_env('CANARY', 'true')
+      expect(entity.as_json[:favicon]).to match_asset_path('/assets/ci_favicons/canary/favicon_status_success.ico')
+    end
   end
 end

vendor/gitlab-ci-yml/autodeploy/Kubernetes-with-canary.gitlab-ci.yml

@@ -28,7 +28,7 @@ build:
 canary:
   stage: canary
   script:
-    - CANARY=true command canary
+    - command canary
   environment:
     name: production
     url: http://$CI_PROJECT_PATH_SLUG.$KUBE_DOMAIN