Move file system archive code into backup package

system/admin/upload/backup.go

@@ -1,15 +1,15 @@
 package upload
 
 import (
-	"archive/tar"
-	"compress/gzip"
 	"context"
 	"fmt"
 	"io"
 	"net/http"
 	"os"
 	"path/filepath"
 	"time"
+
+	"github.com/ponzu-cms/ponzu/system/backup"
 )
 
 // Backup creates an archive of a project's uploads and writes it
@@ -18,105 +18,28 @@ func Backup(ctx context.Context, res http.ResponseWriter) error {
 	ts := time.Now().Unix()
 	filename := fmt.Sprintf("uploads-%d.bak.tar.gz", ts)
 	tmp := os.TempDir()
-	backup := filepath.Join(tmp, filename)
+	bk := filepath.Join(tmp, filename)
 
 	// create uploads-{stamp}.bak.tar.gz
-	f, err := os.Create(backup)
+	f, err := os.Create(bk)
 	if err != nil {
 		return err
 	}
 
-	// loop through directory and gzip files
-	// add all to uploads.bak.tar.gz tarball
-	gz := gzip.NewWriter(f)
-	tarball := tar.NewWriter(gz)
-
-	errChan := make(chan error, 1)
-	walkFn := func(path string, info os.FileInfo, err error) error {
-		if err != nil {
-			return err
-		}
-
-		hdr, err := tar.FileInfoHeader(info, "")
-		if err != nil {
-			return err
-		}
-
-		hdr.Name = path
-
-		err = tarball.WriteHeader(hdr)
-		if err != nil {
-			return err
-		}
-
-		if !info.IsDir() {
-			src, err := os.Open(path)
-			if err != nil {
-				return err
-			}
-			defer src.Close()
-
-			_, err = io.Copy(tarball, src)
-			if err != nil {
-				return err
-			}
-
-			err = tarball.Flush()
-			if err != nil {
-				return err
-			}
-
-			err = gz.Flush()
-			if err != nil {
-				return err
-			}
-		}
-
-		return nil
-	}
-
-	// stop processing if we get a cancellation signal
-	err = filepath.Walk("uploads", func(path string, info os.FileInfo, err error) error {
-		go func() { errChan <- walkFn(path, info, err) }()
+	err = backup.ArchiveFS(ctx, "uploads", f)
 
-		select {
-		case <-ctx.Done():
-			if err := ctx.Err(); err != nil {
-				return err
-			}
-		case err := <-errChan:
-			if err != nil {
-				return err
-			}
-		}
-
-		return nil
-	})
-	if err != nil {
-		fmt.Println(err)
-		return err
-	}
-
-	err = gz.Close()
-	if err != nil {
-		return err
-	}
-	err = tarball.Close()
-	if err != nil {
-		return err
-	}
 	err = f.Close()
 	if err != nil {
 		return err
 	}
 
 	// write data to response
-	data, err := os.Open(backup)
+	data, err := os.Open(bk)
 	if err != nil {
 		return err
 	}
 	defer data.Close()
-	defer os.Remove(backup)
+	defer os.Remove(bk)
 
 	disposition := `attachment; filename=%s`
 	info, err := data.Stat()

system/backup/archive.go

@@ -0,0 +1,95 @@
+package backup
+
+import (
+	"archive/tar"
+	"compress/gzip"
+	"context"
+	"fmt"
+	"io"
+	"os"
+	"path/filepath"
+)
+
+// ArchiveFS walks the filesystem starting from basedir writing files encountered
+// tarred and gzipped to the provided writer
+func ArchiveFS(ctx context.Context, basedir string, w io.Writer) error {
+	gz := gzip.NewWriter(w)
+	tarball := tar.NewWriter(gz)
+
+	errChan := make(chan error, 1)
+	walkFn := func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		hdr, err := tar.FileInfoHeader(info, "")
+		if err != nil {
+			return err
+		}
+
+		hdr.Name = path
+
+		err = tarball.WriteHeader(hdr)
+		if err != nil {
+			return err
+		}
+
+		if !info.IsDir() {
+			src, err := os.Open(path)
+			if err != nil {
+				return err
+			}
+			defer src.Close()
+
+			_, err = io.Copy(tarball, src)
+			if err != nil {
+				return err
+			}
+
+			err = tarball.Flush()
+			if err != nil {
+				return err
+			}
+
+			err = gz.Flush()
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	}
+
+	// stop processing if we get a cancellation signal
+	err := filepath.Walk(basedir, func(path string, info os.FileInfo, err error) error {
+		go func() { errChan <- walkFn(path, info, err) }()
+
+		select {
+		case <-ctx.Done():
+			if err := ctx.Err(); err != nil {
+				return err
+			}
+		case err := <-errChan:
+			if err != nil {
+				return err
+			}
+		}
+
+		return nil
+	})
+	if err != nil {
+		fmt.Println(err)
+		return err
+	}
+
+	err = gz.Close()
+	if err != nil {
+		return err
+	}
+	err = tarball.Close()
+	if err != nil {
+		return err
+	}
+
+	return nil
+}