feat(metrics): wire instrumentation through queue, handlers, middleware

internal/updater/queue_test.go

@@ -7,7 +7,10 @@ import (
 	"testing"
 	"time"
 
+	dto "github.com/prometheus/client_model/go"
+	"github.com/prometheus/client_golang/prometheus"
 	"github.com/shcizo/package-updater/internal/discovery"
+	"github.com/shcizo/package-updater/internal/metrics"
 	"github.com/shcizo/package-updater/internal/updater"
 	"github.com/stretchr/testify/require"
 )
@@ -44,7 +47,7 @@ func (f *fakeExec) callsCopy() []discovery.Job {
 
 func TestQueue_ProcessesFIFO(t *testing.T) {
 	exec := &fakeExec{delay: 20 * time.Millisecond}
-	q := updater.NewQueue(exec)
+	q := updater.NewQueue(exec, nil)
 	q.Start(context.Background())
 	defer q.Stop()
 
@@ -69,7 +72,7 @@ func TestQueue_ProcessesFIFO(t *testing.T) {
 
 func TestQueue_ReturnsPerJobResults(t *testing.T) {
 	exec := &fakeExec{errForSvc: map[string]error{"failing": errors.New("boom")}}
-	q := updater.NewQueue(exec)
+	q := updater.NewQueue(exec, nil)
 	q.Start(context.Background())
 	defer q.Stop()
 
@@ -90,7 +93,7 @@ func TestQueue_ReturnsPerJobResults(t *testing.T) {
 
 func TestQueue_Timeout(t *testing.T) {
 	exec := &fakeExec{delay: 200 * time.Millisecond}
-	q := updater.NewQueue(exec)
+	q := updater.NewQueue(exec, nil)
 	q.Start(context.Background())
 	defer q.Stop()
 
@@ -103,3 +106,24 @@ func TestQueue_Timeout(t *testing.T) {
 	require.Len(t, results, 1)
 	require.Equal(t, updater.StatusTimeout, results[0].Status)
 }
+
+func TestQueue_RecordsMetrics(t *testing.T) {
+	reg := prometheus.NewRegistry()
+	m := metrics.New(reg)
+	exec := &fakeExec{}
+	q := updater.NewQueue(exec, m)
+	q.Start(context.Background())
+	defer q.Stop()
+
+	q.Submit(context.Background(), []discovery.Job{{Project: "p", Service: "s"}})
+
+	// Verify UpdateJobs counter was incremented for the successful job.
+	metric := &dto.Metric{}
+	require.NoError(t, m.UpdateJobs.WithLabelValues("p", "s", "updated").Write(metric))
+	require.Equal(t, 1.0, metric.GetCounter().GetValue())
+
+	// Verify LastUpdateTime was set (non-zero).
+	tsMetric := &dto.Metric{}
+	require.NoError(t, m.LastUpdateTime.WithLabelValues("p", "s").Write(tsMetric))
+	require.Greater(t, tsMetric.GetGauge().GetValue(), 0.0)
+}