xesite: add rebuild metrics

Signed-off-by: Xe Iaso <me@xeiaso.net>

3 files changed, 34 insertions, 9 deletions

diff --git a/go.mod b/go.mod
index e7586ce..5826e97 100644
--- a/go.mod
+++ b/go.mod
@@ -7,7 +7,6 @@ require (
 	github.com/facebookgo/flagenv v0.0.0-20160425205200-fcd59fca7456
 	github.com/go-git/go-git/v5 v5.9.0
 	github.com/joho/godotenv v1.5.1
-	golang.org/x/exp v0.0.0-20230725093048-515e97ebf090
 	tailscale.com v1.48.2
 )
 
@@ -42,6 +41,7 @@ require (
 	go4.org/mem v0.0.0-20220726221520-4f986261bf13 // indirect
 	go4.org/netipx v0.0.0-20230728180743-ad4cb58a6516 // indirect
 	golang.org/x/crypto v0.13.0 // indirect
+	golang.org/x/exp v0.0.0-20230725093048-515e97ebf090 // indirect
 	golang.org/x/mod v0.12.0 // indirect
 	golang.org/x/net v0.15.0 // indirect
 	golang.org/x/sys v0.12.0 // indirect
diff --git a/internal/lume/lume.go b/internal/lume/lume.go
index f347d32..b58fed3 100644
--- a/internal/lume/lume.go
+++ b/internal/lume/lume.go
@@ -11,6 +11,7 @@ import (
 	"os/exec"
 	"path/filepath"
 	"sync"
+	"time"
 
 	"github.com/go-git/go-git/v5"
 	"github.com/go-git/go-git/v5/plumbing"
@@ -25,13 +26,13 @@ var (
 	_ fs.ReadFileFS = (*FS)(nil)
 	_ fs.ReadDirFS  = (*FS)(nil)
 
-	opens        = metrics.LabelMap{Label: "name"}
-	readFiles    = metrics.LabelMap{Label: "name"}
-	readDirs     = metrics.LabelMap{Label: "name"}
-	builds       = expvar.NewInt("gauge_xesite_builds")
-	buildErrors  = expvar.NewInt("gauge_xesite_build_errors")
-	updates      = expvar.NewInt("gauge_xesite_updates")
-	updateErrors = expvar.NewInt("gauge_xesite_update_errors")
+	opens         = metrics.LabelMap{Label: "name"}
+	readFiles     = metrics.LabelMap{Label: "name"}
+	readDirs      = metrics.LabelMap{Label: "name"}
+	builds        = expvar.NewInt("gauge_xesite_builds")
+	updates       = expvar.NewInt("gauge_xesite_updates")
+	updateErrors  = expvar.NewInt("gauge_xesite_update_errors")
+	lastBuildTime = expvar.NewInt("gauge_xesite_last_build_time_ms")
 )
 
 func init() {
@@ -199,6 +200,8 @@ func (f *FS) build(ctx context.Context) error {
 	builds.Add(1)
 	destDir := filepath.Join(f.repoDir, f.opt.StaticSiteDir, "_site")
 
+	begin := time.Now()
+
 	if err := f.writeConfig(); err != nil {
 		return err
 	}
@@ -210,13 +213,16 @@ func (f *FS) build(ctx context.Context) error {
 	cmd.Stderr = os.Stderr
 
 	if err := cmd.Run(); err != nil {
-		buildErrors.Add(1)
 		return err
 	}
 
 	slog.Debug("built site", "dir", destDir)
 
 	f.fs = os.DirFS(destDir)
+	dur := time.Since(begin)
+
+	lastBuildTime.Set(dur.Milliseconds())
+	slog.Info("built site", "time", dur.String())
 
 	return nil
 }
diff --git a/xesite/github.go b/xesite/github.go
index 9d3c484..d74bc0b 100644
--- a/xesite/github.go
+++ b/xesite/github.go
@@ -3,15 +3,27 @@ package main
 import (
 	"context"
 	"encoding/json"
+	"expvar"
+	"fmt"
 	"log/slog"
 	"net/http"
 	"time"
 
 	"github.com/go-git/go-git/v5"
+	"tailscale.com/metrics"
 	"xeiaso.net/v4/internal/github"
 	"xeiaso.net/v4/internal/lume"
 )
 
+var (
+	webhookCount = expvar.NewInt("gauge_xesite_webhook_ingress")
+	buildErrors  = metrics.LabelMap{Label: "err"}
+)
+
+func init() {
+	expvar.Publish("gauge_xesite_build_errors", &buildErrors)
+}
+
 type GitHubWebhook struct {
 	fs *lume.FS
 }
@@ -30,10 +42,17 @@ func (gh *GitHubWebhook) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 
 	slog.Info("push!", "ref", event.Ref, "author", event.Pusher.Login)
 
+	if event.Ref != "refs/heads/"+*gitBranch {
+		slog.Error("not the right branch", "branch", event.Ref)
+		fmt.Fprintln(w, "OK")
+		return
+	}
+
 	go func() {
 		ctx, cancel := context.WithTimeout(context.Background(), 10*time.Minute)
 		defer cancel()
 		if err := gh.fs.Update(ctx); err != nil {
+			buildErrors.Add(err.Error(), 1)
 			if err == git.NoErrAlreadyUpToDate {
 				slog.Info("already up to date")
 				return