Use histogram without labels

Register ServingTime.
Rename DiskServingFileSize so that it's a histogram without
needing labels

4 files changed, 12 insertions, 9 deletions

diff --git a/acceptance_test.go b/acceptance_test.go
index 1cd854d3..7cd2d52d 100644
--- a/acceptance_test.go
+++ b/acceptance_test.go
@@ -405,6 +405,8 @@ func TestPrometheusMetricsCanBeScraped(t *testing.T) {
 	require.Contains(t, string(body), "gitlab_pages_domains_source_failures_total 0")
 	require.Contains(t, string(body), "gitlab_pages_serverless_requests 0")
 	require.Contains(t, string(body), "gitlab_pages_serverless_latency_sum 0")
+	require.Contains(t, string(body), "gitlab_pages_disk_serving_file_size_sum 0")
+	require.Contains(t, string(body), "gitlab_pages_serving_time_sum 0")
 }
 
 func TestStatusPage(t *testing.T) {
diff --git a/internal/serving/disk/reader.go b/internal/serving/disk/reader.go
index 83fe3378..b8dce542 100644
--- a/internal/serving/disk/reader.go
+++ b/internal/serving/disk/reader.go
@@ -17,7 +17,7 @@ import (
 
 // Reader is a disk access driver
 type Reader struct {
-	fileSizeMetric *prometheus.HistogramVec
+	fileSizeMetric prometheus.Histogram
 }
 
 func (reader *Reader) tryFile(h serving.Handler) error {
@@ -144,7 +144,7 @@ func (reader *Reader) serveFile(w http.ResponseWriter, r *http.Request, origPath
 		return err
 	}
 
-	reader.fileSizeMetric.With(prometheus.Labels{"serving_type": "disk", "content_type": contentType}).Observe(float64(fi.Size()))
+	reader.fileSizeMetric.Observe(float64(fi.Size()))
 
 	w.Header().Set("Content-Type", contentType)
 	http.ServeContent(w, r, origPath, fi.ModTime(), file)
@@ -172,7 +172,7 @@ func (reader *Reader) serveCustomFile(w http.ResponseWriter, r *http.Request, co
 		return err
 	}
 
-	reader.fileSizeMetric.With(prometheus.Labels{"serving_type": "disk", "content_type": contentType}).Observe(float64(fi.Size()))
+	reader.fileSizeMetric.Observe(float64(fi.Size()))
 
 	w.Header().Set("Content-Type", contentType)
 	w.Header().Set("Content-Length", strconv.FormatInt(fi.Size(), 10))
diff --git a/internal/serving/disk/serving.go b/internal/serving/disk/serving.go
index 94a6d001..f5ec0d78 100644
--- a/internal/serving/disk/serving.go
+++ b/internal/serving/disk/serving.go
@@ -8,7 +8,7 @@ import (
 
 var disk = &Disk{
 	reader: Reader{
-		fileSizeMetric: metrics.ServingFileSize,
+		fileSizeMetric: metrics.DiskServingFileSize,
 	},
 }
 
diff --git a/metrics/metrics.go b/metrics/metrics.go
index 7e6d72e1..1266a3aa 100644
--- a/metrics/metrics.go
+++ b/metrics/metrics.go
@@ -77,11 +77,11 @@ var (
 		Help: "The time (in seconds) it takes to get a response from the GitLab domains API",
 	}, []string{"status_code"})
 
-	// ServingFileSize metric for file size serving. serving_types: disk and object_storage
-	ServingFileSize = prometheus.NewHistogramVec(prometheus.HistogramOpts{
-		Name: "gitlab_pages_serving_file_size",
+	// DiskServingFileSize metric for file size serving. serving_types: disk and object_storage
+	DiskServingFileSize = prometheus.NewHistogram(prometheus.HistogramOpts{
+		Name: "gitlab_pages_disk_serving_file_size",
 		Help: "The size in bytes for each file that has been served",
-	}, []string{"serving_type", "content_type"})
+	})
 
 	// ServingTime metric for time taken to find a file serving it or not found.
 	ServingTime = prometheus.NewHistogram(prometheus.HistogramOpts{
@@ -105,6 +105,7 @@ func MustRegister() {
 		DomainsSourceFailures,
 		ServerlessRequests,
 		ServerlessLatency,
-		ServingFileSize,
+		DiskServingFileSize,
+		ServingTime,
 	)
 }