custom health check to verify mail password is set

config/initializers/okcomputer.rb

@@ -1,3 +1,5 @@
+require 'net/smtp'
+
 # frozen_string_literal: true
 
 # Health check configuration
@@ -6,7 +8,7 @@
 OkComputer.check_in_parallel = true
 
 class AlmaPatronCheck < OkComputer::Check
-  TEST_PATRON_ID = '[email protected]'
+  TEST_PATRON_ID = '[email protected]'.freeze
 
   def check
     Alma::User.find(TEST_PATRON_ID)
@@ -18,11 +20,47 @@ def check
   end
 end
 
+# rubocop:disable Metrics/MethodLength, Metrics/AbcSize
+class MailConnectivityCheck < OkComputer::Check
+  OkComputer::Registry.register 'mail-connectivity', MailConnectivityCheck.new if ActionMailer::Base.delivery_method == :smtp
+
+  # Check that the mail password is set
+  def check
+    settings = ActionMailer::Base.smtp_settings
+    begin
+      Net::SMTP.start(
+        settings[:address],
+        settings[:port],
+        settings[:domain],
+        settings[:user_name],
+        settings[:password],
+        settings[:authentication],
+        tls: true
+      ) { mark_message 'Connection for smtp successful' }
+    rescue Net::SMTPAuthenticationError => e
+      mark_failure
+      Rails.logger.warn "SMTP authentication error: #{e}"
+      mark_message 'SMTP Error: Authentication failed. Check logs for more details'
+    rescue Net::SMTPServerBusy, Net::SMTPSyntaxError, Net::SMTPFatalError, Net::SMTPUnknownError => e
+      mark_failure
+      Rails.logger.warn "SMTP Error: #{e}"
+      mark_message 'SMTP error. Check logs for more details'
+    rescue IOError, Net::ReadTimeout => e
+      mark_failure
+      Rails.logger.warn "SMTP Timeout: #{e}"
+      mark_message 'SMTP Connection error: Timeout. Check logs for more details'
+    rescue StandardError => e
+      # Catch any other unexpected errors
+      mark_failure
+      Rails.logger.warn "SMTP standard error: #{e}"
+      mark_message 'SMTP ERROR: Could not connect. Check logs for more details'
+    end
+  end
+end
+# rubocop:enable Metrics/MethodLength, Metrics/AbcSize
+
 # Ensure Alma API is working.
 OkComputer::Registry.register 'alma-patron-lookup', AlmaPatronCheck.new
 
 # Ensure database migrations have been run.
 OkComputer::Registry.register 'database-migrations', OkComputer::ActiveRecordMigrationsCheck.new
-
-# Ensure connectivity to the mail system.
-OkComputer::Registry.register 'action-mailer', OkComputer::ActionMailerCheck.new

spec/request/okcomputer_spec.rb

@@ -11,7 +11,7 @@
   it 'returns all checks to /health' do
     get '/health'
     expect(response.parsed_body.keys).to match_array %w[
-      action-mailer
+      mailer-connectivity 
       alma-patron-lookup
       default
       database