Add file duration

main.go

@@ -3,9 +3,11 @@ package main
 import (
 	"crypto/rand"
 	"encoding/json"
+	"errors"
 	"fmt"
 	"html/template"
 	"io"
+	"io/fs"
 	"log"
 	"mime"
 	"net/http"
@@ -27,6 +29,17 @@ func main() {
 	if uploadDir == "" {
 		uploadDir = "/uploads"
 	}
+	var fileExpires time.Duration = 7 * 24 * time.Hour
+
+	dryRun := strings.ToLower(os.Getenv("DRYRUN_CLEAN")) != "false"
+	fileDuration := os.Getenv("FILE_DURATION")
+	if fileDuration != "" {
+		expires, err := time.ParseDuration(fileDuration)
+		if err != nil {
+			log.Fatalf("FILE_DURATION %s is invalid: %v", fileDuration, err)
+		}
+		fileExpires = expires
+	}
 
 	port := os.Getenv("PORT")
 	if port == "" {
@@ -40,6 +53,13 @@ func main() {
 	http.HandleFunc("/", handleRequest)
 
 	log.Printf("Starting server on port %s, upload directory: %s", port, uploadDir)
+	log.Printf("Files expires after: %v (DRYRUN_CLEAN=%v)", fileExpires, dryRun)
+	if fileExpires != 0 {
+		go cleanupProcedure(fileExpires, dryRun)
+	} else {
+		log.Print("Cleaning old files is disabled")
+	}
+
 	if err := http.ListenAndServe(":"+port, nil); err != nil {
 		log.Fatalf("Server failed: %v", err)
 	}
@@ -325,3 +345,95 @@ func serveFrontpage(w http.ResponseWriter, r *http.Request) {
 	w.Header().Set("Content-Type", "text/html; charset=utf-8")
 	indexHTML.Execute(w, pageData)
 }
+
+// Cleanup
+
+func isDirEmpty(name string) (bool, error) {
+	f, err := os.Open(name)
+	if err != nil {
+		return false, err
+	}
+	defer f.Close()
+
+	// Read exactly one entry.
+	_, err = f.ReadDir(1)
+	if errors.Is(err, io.EOF) {
+		// EOF means there are no entries, so the directory is empty.
+		return true, nil
+	}
+
+	// If err is nil, an entry was found (not empty).
+	// If err is something else, a real error occurred.
+	return false, err
+}
+
+func cleanupProcedure(duration time.Duration, dryRun bool) {
+	var oldFiles []string
+	var emptyDirs []string
+
+	deleteIfTooOld := func(path string, d fs.DirEntry, err error) error {
+		if err != nil {
+			return nil
+		}
+		if d.IsDir() {
+			return nil
+		}
+
+		info, err := d.Info()
+		if err != nil {
+			log.Printf("Error cleaning file '%s' : %v", d.Name(), err)
+			return nil
+		}
+		age := time.Since(info.ModTime())
+		if age >= duration {
+			oldFiles = append(oldFiles, path)
+		}
+		return nil
+	}
+
+	findEmptyDirs := func(path string, d fs.DirEntry, err error) error {
+		if !d.IsDir() {
+			return nil
+		}
+		empty, err := isDirEmpty(path)
+		if empty {
+			emptyDirs = append(emptyDirs, path)
+		} else if err != nil {
+			log.Printf("Error cleaning directory '%s' : %v", path, err)
+		}
+
+		return nil
+	}
+
+	for {
+
+		filepath.WalkDir(uploadDir, deleteIfTooOld)
+		for _, file := range oldFiles {
+			if !dryRun {
+				err := os.Remove(file)
+				if err != nil {
+					log.Printf("Failed to remove expired file '%s' : %v", file, err)
+				} else {
+					log.Printf("Removed expired file '%s'", file)
+				}
+			} else {
+				log.Printf("Dry run: Would remove expired file '%s'", file)
+			}
+		}
+
+		filepath.WalkDir(uploadDir, findEmptyDirs)
+		for _, file := range emptyDirs {
+			if !dryRun {
+				err := os.Remove(file)
+				if err != nil {
+					log.Printf("Failed to remove empty folder '%s' : %v", file, err)
+				} else {
+					log.Printf("Removed empty folder '%s'", file)
+				}
+			} else {
+				log.Printf("Dry run: Would remove empty folder '%s'", file)
+			}
+		}
+		time.Sleep(6 * time.Hour)
+	}
+}