feat: Implement simple page metrics

internal/pages/metrics.go

@@ -0,0 +1,56 @@
+package pages
+
+import (
+	"encoding/json"
+	"net/http"
+	"strconv"
+	"strings"
+	"time"
+
+	log "github.com/sirupsen/logrus"
+)
+
+type LokiMetricConfig struct {
+	Url     string
+	Enabled bool
+}
+
+// Checks if we should send a metric ping to Loki based on the served path.
+func (c *LokiMetricConfig) shouldSendMetrics(path string) bool {
+	return strings.HasSuffix(path, ".html") && c.Enabled
+}
+
+func (c *LokiMetricConfig) sendMetricPing(domain, path string) {
+	data := map[string]interface{}{
+		"steams": []map[string]interface{}{
+			{
+				"stream": map[string]string{
+					// Labels
+					"service": "rio",
+					"domain":  domain,
+					"type":    "metric",
+				},
+				"values": [][]interface{}{
+					{
+						strconv.Itoa(int(time.Now().UnixNano())),
+						"path=" + path,
+					},
+				},
+			},
+		},
+	}
+	jsonData, err := json.Marshal(data)
+	if err != nil {
+		log.Errorf("Failed to send metric ping to Loki: %v", err)
+		return
+	}
+
+	// Send the ping to the Loki server
+	go func() {
+		http.Post(
+			c.Url,
+			"application/json",
+			strings.NewReader(string(jsonData)),
+		)
+	}()
+}

internal/pages/pages.go

@@ -45,7 +45,7 @@ func addHeaders(csp, contentType string, contentLength int, w http.ResponseWrite
 	}
 }
 
-func ServeFile(username, reponame, path, defaultCsp string, giteaClient *repo.GiteaClient, w http.ResponseWriter) {
+func ServeFile(username, reponame, path, defaultCsp, domain string, giteaClient *repo.GiteaClient, metricConfig *LokiMetricConfig, w http.ResponseWriter) {
 	// Strip away a starting / as it messes with Gitea
 	if path[:1] == "/" {
 		path = path[1:]
@@ -116,4 +116,9 @@ func ServeFile(username, reponame, path, defaultCsp string, giteaClient *repo.Gi
 	addHeaders(csp, mimeType, len(content), w)
 	w.WriteHeader(200)
 	w.Write(content)
+
+	// Tell Loki about if, if desired
+	if metricConfig.shouldSendMetrics(path) {
+		metricConfig.sendMetricPing(domain, path)
+	}
 }