Merge pull request #6546 from pulibrary/cache_smtp

SMTP check should happen every 5 minutes.

app/monitors/smtp_status.rb

@@ -1,10 +1,19 @@
 # frozen_string_literal: true
 class SmtpStatus < HealthMonitor::Providers::Base
+  class << self
+    attr_writer :next_check_timestamp
+
+    def next_check_timestamp
+      @next_check_timestamp || 0
+    end
+  end
   def check!
+    return unless Time.current > self.class.next_check_timestamp
     settings = ActionMailer::Base.smtp_settings
     tls_setting = settings[:enable_starttls] == false ? false : :auto
     smtp = Net::SMTP.new(settings[:address], settings[:port], starttls: tls_setting)
     smtp.open_timeout = 1
     smtp.start
+    self.class.next_check_timestamp = Time.current + 5.minutes
   end
 end

spec/requests/health_monitor_spec.rb

@@ -27,11 +27,25 @@
     end
 
     it "errors when it can't contact the SMTP server" do
+      SmtpStatus.next_check_timestamp = 0
       get "/health.json?providers[]=smtpstatus"
 
       expect(response).not_to be_successful
     end
 
+    it "caches a success on SMTP and doesn't call it twice in a short window" do
+      smtp_double = instance_double(Net::SMTP)
+      allow(Net::SMTP).to receive(:new).and_return(smtp_double)
+      allow(smtp_double).to receive(:open_timeout=)
+      allow(smtp_double).to receive(:start)
+
+      get "/health.json?providers[]=smtpstatus"
+      expect(response).to be_successful
+      get "/health.json?providers[]=smtpstatus"
+
+      expect(Net::SMTP).to have_received(:new).exactly(1).times
+    end
+
     it "errors when solr is down" do
       allow(Blacklight.default_index.connection).to receive(:uri).and_return(URI("http://example.com/bla"))
       stub_request(:get, "http://example.com/solr/admin/cores?action=STATUS").to_return(body: { responseHeader: { status: 500 } }.to_json, headers: { "Content-Type" => "text/json" })