Add metrics tests for vectors

1 files changed, 60 insertions, 0 deletions

diff --git a/metrics/metrics_test.go b/metrics/metrics_test.go
new file mode 100644
index 00000000..c65aab3c
--- /dev/null
+++ b/metrics/metrics_test.go
@@ -0,0 +1,60 @@
+package metrics
+
+import (
+	"io/ioutil"
+	"net/http"
+	"net/http/httptest"
+	"testing"
+	"time"
+
+	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp"
+	"github.com/prometheus/client_golang/prometheus/testutil"
+	"github.com/stretchr/testify/require"
+)
+
+func TestMetricsVectorsCanBeScraped(t *testing.T) {
+	reg := prometheus.NewRegistry()
+
+	// vectors will only be available in /metrics after a label has been set/incremented so we can't test these in
+	// TestPrometheusMetricsCanBeScraped as part of the acceptance tests
+	reg.MustRegister(
+		DomainsSourceAPIReqTotal,
+		DomainsSourceAPICallDuration,
+		ZipFileServingReqTotal,
+		ZipFileServingReqDuration,
+	)
+
+	handler := promhttp.HandlerFor(reg, promhttp.HandlerOpts{})
+	testServer := httptest.NewServer(handler)
+	defer testServer.Close()
+
+	DomainsSourceAPICallDuration.WithLabelValues("200").Set(float64(20 * time.Millisecond))
+	DomainsSourceAPIReqTotal.WithLabelValues("200").Inc()
+
+	c, err := DomainsSourceAPIReqTotal.GetMetricWithLabelValues("200")
+	require.NoError(t, err)
+	require.Equal(t, float64(1), testutil.ToFloat64(c))
+
+	ZipFileServingReqDuration.WithLabelValues("200").Set(float64(20 * time.Millisecond))
+	ZipFileServingReqTotal.WithLabelValues("200").Inc()
+
+	c, err = ZipFileServingReqTotal.GetMetricWithLabelValues("200")
+	require.NoError(t, err)
+	require.Equal(t, float64(1), testutil.ToFloat64(c))
+
+	metricFamilies, err := reg.Gather()
+	require.NoError(t, err)
+
+	require.Len(t, metricFamilies, 4)
+
+	res, err := http.Get(testServer.URL + "/metrics")
+	require.NoError(t, err)
+	defer res.Body.Close()
+	body, _ := ioutil.ReadAll(res.Body)
+
+	require.Contains(t, string(body), `gitlab_pages_domains_source_api_requests_total{status_code="200"}`)
+	require.Contains(t, string(body), `gitlab_pages_domains_source_api_call_duration{status_code="200"}`)
+	require.Contains(t, string(body), `gitlab_pages_httprange_zip_reader_requests_total{status_code="200"}`)
+	require.Contains(t, string(body), `gitlab_pages_httprange_zip_reader_requests_duration{status_code="200"}`)
+}