Protect changing in parallel using HTTP 412 precondition failed

2025-11-26 21:58:39 +02:00
parent 90d896e1cc
commit 9dce53eded
5 changed files with 80 additions and 102 deletions
@@ -4,128 +4,70 @@ import (
 	"log"
 	"net/http"
 	"os"
-	"path/filepath"

 	"github.com/pocketbase/pocketbase"
 	"github.com/pocketbase/pocketbase/apis"
 	"github.com/pocketbase/pocketbase/core"
-	"github.com/pocketbase/pocketbase/plugins/ghupdate"
-	"github.com/pocketbase/pocketbase/plugins/jsvm"
-	"github.com/pocketbase/pocketbase/plugins/migratecmd"
-	"github.com/pocketbase/pocketbase/tools/hook"
-	"github.com/pocketbase/pocketbase/tools/osutils"
+	"github.com/pocketbase/pocketbase/lubinas"
 )

 func main() {
 	app := pocketbase.New()

-	// ---------------------------------------------------------------
-	// Optional plugin flags:
-	// ---------------------------------------------------------------
-
-	var hooksDir string
-	app.RootCmd.PersistentFlags().StringVar(
-		&hooksDir,
-		"hooksDir",
-		"",
-		"the directory with the JS app hooks",
-	)
-
-	var hooksWatch bool
-	app.RootCmd.PersistentFlags().BoolVar(
-		&hooksWatch,
-		"hooksWatch",
-		true,
-		"auto restart the app on pb_hooks file change; it has no effect on Windows",
-	)
-
-	var hooksPool int
-	app.RootCmd.PersistentFlags().IntVar(
-		&hooksPool,
-		"hooksPool",
-		15,
-		"the total prewarm goja.Runtime instances for the JS app hooks execution",
-	)
-
-	var migrationsDir string
-	app.RootCmd.PersistentFlags().StringVar(
-		&migrationsDir,
-		"migrationsDir",
-		"",
-		"the directory with the user defined migrations",
-	)
-
-	var automigrate bool
-	app.RootCmd.PersistentFlags().BoolVar(
-		&automigrate,
-		"automigrate",
-		true,
-		"enable/disable auto migrations",
-	)
-
-	var publicDir string
-	app.RootCmd.PersistentFlags().StringVar(
-		&publicDir,
-		"publicDir",
-		defaultPublicDir(),
-		"the directory to serve static files",
-	)
-
-	var indexFallback bool
-	app.RootCmd.PersistentFlags().BoolVar(
-		&indexFallback,
-		"indexFallback",
-		true,
-		"fallback the request to index.html on missing static path, e.g. when pretty urls are used with SPA",
-	)
-
 	app.RootCmd.ParseFlags(os.Args[1:])

-	// ---------------------------------------------------------------
-	// Plugins and hooks:
-	// ---------------------------------------------------------------
+	app.OnServe().BindFunc(func(se *core.ServeEvent) error {
+		se.Router.GET("/{path...}", apis.Static(lubinas.DistDirFS, true)).
+			BindFunc(func(e *core.RequestEvent) error {
+				// ignore root path
+				if e.Request.PathValue(apis.StaticWildcardParam) != "" {
+					e.Response.Header().Set("Cache-Control", "max-age=1209600, stale-while-revalidate=86400")
+				}

-	// load jsvm (pb_hooks and pb_migrations)
-	jsvm.MustRegister(app, jsvm.Config{
-		MigrationsDir: migrationsDir,
-		HooksDir:      hooksDir,
-		HooksWatch:    hooksWatch,
-		HooksPoolSize: hooksPool,
+				return e.Next()
+			}).
+			Bind(apis.Gzip())
+
+		return se.Next()
 	})

-	// migrate command (with js templates)
-	migratecmd.MustRegister(app, app.RootCmd, migratecmd.Config{
-		TemplateLang: migratecmd.TemplateLangJS,
-		Automigrate:  automigrate,
-		Dir:          migrationsDir,
-	})
+	app.OnRecordViewRequest().BindFunc(addLastModified)

-	// GitHub selfupdate
-	ghupdate.MustRegister(app, app.RootCmd, ghupdate.Config{})
+	app.OnRecordUpdateRequest().BindFunc(ifUnmodifiedSince)

-	// static route to serves files from the provided public dir
-	// (if publicDir exists and the route path is not already defined)
-	app.OnServe().Bind(&hook.Handler[*core.ServeEvent]{
-		Func: func(e *core.ServeEvent) error {
-			if !e.Router.HasRoute(http.MethodGet, "/{path...}") {
-				e.Router.GET("/{path...}", apis.Static(os.DirFS(publicDir), indexFallback))
-			}
-
-			return e.Next()
-		},
-		Priority: 999, // execute as latest as possible to allow users to provide their own route
-	})
+	app.OnRecordDeleteRequest().BindFunc(ifUnmodifiedSince)

 	if err := app.Start(); err != nil {
 		log.Fatal(err)
 	}
 }

-// the default pb_public dir location is relative to the executable
-func defaultPublicDir() string {
-	if osutils.IsProbablyGoRun() {
-		return "./pb_public"
+func addLastModified(e *core.RecordRequestEvent) error {
+	updated := e.Record.GetString("updated")
+
+	if updated != "" {
+		e.Response.Header().Add("Last-Modified", updated)
 	}

-	return filepath.Join(os.Args[0], "../pb_public")
+	return e.Next()
+}
+
+func ifUnmodifiedSince(e *core.RecordRequestEvent) error {
+	updated := e.Record.GetString("updated")
+
+	if updated != "" {
+		header := e.Request.Header.Get("If-Unmodified-Since")
+
+		if header == "" || header != updated {
+			e.Response.Header().Add("Last-Modified", updated)
+
+			if header == "" {
+				return e.Error(http.StatusPreconditionRequired, "Header If-Unmodified-Since is required", nil)
+			} else if header != updated {
+				return e.Error(http.StatusPreconditionFailed, "Record was modified after retrieval", nil)
+			}
+		}
+	}
+
+	return e.Next()
 }