Add license FAQ link to license expired message

Add a FAQ link to the license we display to users when their license is
expired, or is about to expire.

finishes:
https://gitlab.com/gitlab-org/gitlab/issues/7681

changelogs/unreleased/jswain_add_renewal_link_to_expiration_banner.yml

+---
+title: Add license FAQ link to license expired message
+merge_request:
+author:
+type: added

ee/app/helpers/license_helper.rb

@@ -48,6 +48,13 @@ module LicenseHelper
       message << 'service.'
     end
 
+    unless is_trial
+      renewal_faq_url = 'https://about.gitlab.com/pricing/licensing-faq/#self-managed-gitlab'
+      renewal_faq_link_start = "<a href='#{renewal_faq_url}' target='_blank'>".html_safe
+      link_end = '</a>'.html_safe
+      message << _('For renewal instructions %{link_start}view our Licensing FAQ.%{link_end}') % { link_start: renewal_faq_link_start, link_end: link_end }
+    end
+
     message.join(' ').html_safe
   end
 

ee/spec/helpers/license_helper_spec.rb

@@ -9,6 +9,32 @@ describe LicenseHelper do
   end
 
   describe '#license_message' do
+    context 'license installed' do
+      subject { license_message(signed_in: true, is_admin: false) }
+
+      let(:license) { double('License') }
+      let(:faq_link_regex) { /For renewal instructions <a href.*>view our Licensing FAQ\.<\/a>/ }
+
+      before do
+        allow(License).to receive(:current).and_return(license)
+        allow(license).to receive(:notify_users?).and_return(true)
+        allow(license).to receive(:expired?).and_return(false)
+        allow(license).to receive(:remaining_days).and_return(4)
+      end
+
+      it 'does NOT have a license faq link if license is a trial' do
+        allow(license).to receive(:trial?).and_return(true)
+
+        expect(subject).not_to match(faq_link_regex)
+      end
+
+      it 'has license faq link if license is not a trial' do
+        allow(license).to receive(:trial?).and_return(false)
+
+        expect(subject).to match(faq_link_regex)
+      end
+    end
+
     context 'no license installed' do
       before do
         allow(License).to receive(:current).and_return(nil)

locale/gitlab.pot

@@ -8450,6 +8450,9 @@ msgstr ""
 msgid "For public projects, anyone can view pipelines and access job details (output logs and artifacts)"
 msgstr ""
 
+msgid "For renewal instructions %{link_start}view our Licensing FAQ.%{link_end}"
+msgstr ""
+
 msgid "Forgot your password?"
 msgstr ""