Clarify EmailsOnPushService options.

app/models/project_services/emails_on_push_service.rb

@@ -44,9 +44,12 @@ class EmailsOnPushService < Service
   end
 
   def fields
+    domains = Notify.allowed_email_domains.map { |domain| "user@#{domain}" }.join(", ")
     [
-      { type: 'checkbox', name: 'send_from_committer_email', title: "Send from committer email if domain matches" },
-      { type: 'checkbox', name: 'disable_diffs', title: "Disable code diffs" },
+      { type: 'checkbox', name: 'send_from_committer_email', title: "Send from committer", 
+        help: "Send notifications from the committer's email address if the domain is part of the domain GitLab is running on (e.g. #{domains})." },
+      { type: 'checkbox', name: 'disable_diffs', title: "Disable code diffs",
+        help: "Don't include possibly sensitive code diffs in notification body." },
       { type: 'textarea', name: 'recipients', placeholder: 'Emails separated by whitespace' },
     ]
   end

app/views/admin/services/_form.html.haml

@@ -22,6 +22,7 @@
     - placeholder = field[:placeholder]
     - choices = field[:choices]
     - default_choice = field[:default_choice]
+    - help = field[:help]
 
     .form-group
       = f.label name, title, class: "control-label"
@@ -36,6 +37,8 @@
           = f.select name, options_for_select(choices, value ? value : default_choice), {}, { class: "form-control" }
         - elsif type == 'password'
           = f.password_field name, class: 'form-control'
+        - if help
+          %span.help-block= help
 
   .form-actions
     = f.submit 'Save', class: 'btn btn-save'

app/views/projects/services/_form.html.haml

@@ -35,6 +35,7 @@
     - placeholder = field[:placeholder]
     - choices = field[:choices]
     - default_choice = field[:default_choice]
+    - help = field[:help]
 
     .form-group
       = f.label name, title, class: "control-label"
@@ -49,6 +50,8 @@
           = f.select name, options_for_select(choices, value ? value : default_choice), {}, { class: "form-control" }
         - elsif type == 'password'
           = f.password_field name, class: 'form-control'
+        - if help
+          %span.help-block= help
 
   .form-actions
     = f.submit 'Save', class: 'btn btn-save'