email-exporter: Count Pardot API errors encountered (#8175)

email/exporter.go

@@ -41,6 +41,7 @@ type ExporterImpl struct {
 	limiter               *rate.Limiter
 	client                PardotClient
 	emailsHandledCounter  prometheus.Counter
+	pardotErrorCounter    prometheus.Counter
 	log                   blog.Logger
 }
 
@@ -62,12 +63,19 @@ func NewExporterImpl(client PardotClient, perDayLimit float64, maxConcurrentRequ
 	})
 	scope.MustRegister(emailsHandledCounter)
 
+	pardotErrorCounter := prometheus.NewCounter(prometheus.CounterOpts{
+		Name: "email_exporter_errors",
+		Help: "Total number of Pardot API errors encountered by the email exporter",
+	})
+	scope.MustRegister(pardotErrorCounter)
+
 	impl := &ExporterImpl{
 		maxConcurrentRequests: maxConcurrentRequests,
 		limiter:               limiter,
 		toSend:                make([]string, 0, contactsQueueCap),
 		client:                client,
 		emailsHandledCounter:  emailsHandledCounter,
+		pardotErrorCounter:    pardotErrorCounter,
 		log:                   logger,
 	}
 	impl.wake = sync.NewCond(&impl.Mutex)
@@ -145,6 +153,7 @@ func (impl *ExporterImpl) Start(daemonCtx context.Context) {
 
 			err = impl.client.SendContact(email)
 			if err != nil {
+				impl.pardotErrorCounter.Inc()
 				impl.log.Errf("Sending Contact to Pardot: %s", err)
 			}
 			impl.emailsHandledCounter.Inc()

email/exporter_test.go

@@ -12,6 +12,8 @@ import (
 	blog "github.com/letsencrypt/boulder/log"
 	"github.com/letsencrypt/boulder/metrics"
 	"github.com/letsencrypt/boulder/test"
+
+	"github.com/prometheus/client_golang/prometheus"
 )
 
 var ctx = context.Background()
@@ -88,6 +90,9 @@ func TestSendContacts(t *testing.T) {
 	}
 	test.AssertSliceContains(t, gotContacts, wantContacts[0])
 	test.AssertSliceContains(t, gotContacts, wantContacts[1])
+
+	// Check that the error counter was not incremented.
+	test.AssertMetricWithLabelsEquals(t, exporter.pardotErrorCounter, prometheus.Labels{}, 0)
 }
 
 func TestSendContactsQueueFull(t *testing.T) {
@@ -130,3 +135,31 @@ func TestSendContactsQueueDrains(t *testing.T) {
 
 	test.AssertEquals(t, 100, len(clientImpl.getCreatedContacts()))
 }
+
+type mockAlwaysFailClient struct{}
+
+func (m *mockAlwaysFailClient) SendContact(email string) error {
+	return fmt.Errorf("simulated failure")
+}
+
+func TestSendContactsErrorMetrics(t *testing.T) {
+	t.Parallel()
+
+	mockClient := &mockAlwaysFailClient{}
+	exporter := NewExporterImpl(mockClient, 1000000, 5, metrics.NoopRegisterer, blog.NewMock())
+
+	daemonCtx, cancel := context.WithCancel(context.Background())
+	exporter.Start(daemonCtx)
+
+	_, err := exporter.SendContacts(ctx, &emailpb.SendContactsRequest{
+		Emails: []string{"test@example.com"},
+	})
+	test.AssertNotError(t, err, "Error creating contacts")
+
+	// Drain the queue.
+	cancel()
+	exporter.Drain()
+
+	// Check that the error counter was incremented.
+	test.AssertMetricWithLabelsEquals(t, exporter.pardotErrorCounter, prometheus.Labels{}, 1)
+}