feat: Implement simple page metrics

cmd/rio/main.go

@@ -24,7 +24,7 @@ import (
 	"github.com/urfave/cli/v2"
 )
 
-func handleSubdomain(pagesDomain, domain, cname, path, giteaUrl, defaultCsp string, giteaClient *repo.GiteaClient, w http.ResponseWriter) {
+func handleSubdomain(pagesDomain, domain, cname, path, giteaUrl, defaultCsp string, giteaClient *repo.GiteaClient, lokiConfig *pages.LokiMetricConfig, w http.ResponseWriter) {
 	username := ""
 	if cname != "" {
 		// If we are accessed via a CNAME, then CNAME contains our <user>.<pages domain> value.
@@ -60,10 +60,10 @@ func handleSubdomain(pagesDomain, domain, cname, path, giteaUrl, defaultCsp stri
 		return
 	}
 
-	pages.ServeFile(username, repo.Name, path, defaultCsp, giteaClient, w)
+	pages.ServeFile(username, repo.Name, path, defaultCsp, domain, giteaClient, lokiConfig, w)
 }
 
-func Handler(pagesDomain, giteaUrl, defaultCsp string, giteaClient *repo.GiteaClient) http.HandlerFunc {
+func Handler(pagesDomain, giteaUrl, defaultCsp string, giteaClient *repo.GiteaClient, lokiConfig *pages.LokiMetricConfig) http.HandlerFunc {
 	return func(w http.ResponseWriter, req *http.Request) {
 		w.Header().Set("Server", "rio")
 
@@ -79,7 +79,7 @@ func Handler(pagesDomain, giteaUrl, defaultCsp string, giteaClient *repo.GiteaCl
 		// Is a direct subdomain requested?
 		if strings.HasSuffix(req.Host, pagesDomain) {
 			log.Debug("Domain can be directly handled")
-			handleSubdomain(pagesDomain, req.Host, "", req.URL.Path, giteaUrl, defaultCsp, giteaClient, w)
+			handleSubdomain(pagesDomain, req.Host, "", req.URL.Path, giteaUrl, defaultCsp, giteaClient, lokiConfig, w)
 			return
 		}
 
@@ -96,7 +96,7 @@ func Handler(pagesDomain, giteaUrl, defaultCsp string, giteaClient *repo.GiteaCl
 		//       pages domain makes no sense.
 		if strings.HasSuffix(cname, "."+pagesDomain) {
 			log.Debugf("%s is alias of %s and can be handled after a CNAME query", req.Host, cname)
-			handleSubdomain(pagesDomain, req.Host, cname, req.URL.Path, giteaUrl, defaultCsp, giteaClient, w)
+			handleSubdomain(pagesDomain, req.Host, cname, req.URL.Path, giteaUrl, defaultCsp, giteaClient, lokiConfig, w)
 			return
 		}
 
@@ -131,6 +131,7 @@ func runServer(ctx *cli.Context) error {
 	acmeDnsProvider := ctx.String("acme-dns-provider")
 	acmeDisable := ctx.Bool("acme-disable")
 	defaultCsp := ctx.String("default-csp")
+	lokiUrl := ctx.String("loki-url")
 
 	// Init Logging
 	if ctx.Bool("debug") {
@@ -139,6 +140,19 @@ func runServer(ctx *cli.Context) error {
 		log.SetLevel(log.InfoLevel)
 	}
 
+	// Set up the Loki metrics
+	var lokiConfig pages.LokiMetricConfig
+	if lokiUrl == "" {
+		lokiConfig = pages.LokiMetricConfig{
+			Enabled: false,
+		}
+	} else {
+		lokiConfig = pages.LokiMetricConfig{
+			Enabled: true,
+			Url:     lokiUrl,
+		}
+	}
+
 	// Setup the Gitea stuff
 	httpClient := http.Client{Timeout: 10 * time.Second}
 	giteaApiClient, err := gitea.NewClient(
@@ -240,7 +254,7 @@ func runServer(ctx *cli.Context) error {
 		defer waitGroup.Done()
 
 		log.Debug("Listening on main HTTP server")
-		if err := http.Serve(listener, Handler(domain, giteaUrl, defaultCsp, &giteaClient)); err != nil {
+		if err := http.Serve(listener, Handler(domain, giteaUrl, defaultCsp, &giteaClient, &lokiConfig)); err != nil {
 			log.Fatal(fmt.Errorf("Listening failed: %v", err))
 		}
 		log.Debug("Listening on main HTTP server done!")
@@ -350,6 +364,12 @@ func main() {
 				Value:   "",
 				EnvVars: []string{"DEFAULT_CSP"},
 			},
+			&cli.StringFlag{
+				Name:    "loki-url",
+				Usage:   "The URL for Loki metric pings",
+				Value:   "",
+				EnvVars: []string{"LOKI_URL"},
+			},
 		},
 	}
 

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)
+	}
 }