allows for mode with 1 to 4 digital octal values

Allows for chmod compatible octal values specification in configuration.

modules/logging/filewriter.go

@@ -15,6 +15,7 @@
 package logging
 
 import (
+	"encoding/json"
 	"fmt"
 	"io"
 	"math"
@@ -33,6 +34,43 @@ func init() {
 	caddy.RegisterModule(FileWriter{})
 }
 
+// FileMode is a string made of 1 to 4 octal digits representing
+// a numeric mode as specified with the `chmod` unix command.
+// `"0777"` and `"777"` are thus equivalent values.
+type FileMode os.FileMode
+
+// UnmarshalJSON satisfies json.Unmarshaler.
+func (m *FileMode) UnmarshalJSON(b []byte) error {
+	if len(b) == 0 {
+		return io.EOF
+	}
+
+	var s string
+	if err := json.Unmarshal(b, &s); err != nil {
+		return err
+	}
+
+	mode, err := ParseFileMode(s)
+	if err != nil {
+		return err
+	}
+
+	*m = FileMode(mode)
+	return err
+}
+
+// ParseFileMode parses a file mode string,
+// adding support for `chmod` unix command like
+// 1 to 4 digital octal values.
+func ParseFileMode(s string) (os.FileMode, error) {
+	modeStr := fmt.Sprintf("%04s", s)
+	mode, err := strconv.ParseUint(modeStr, 8, 32)
+	if err != nil {
+		return 0, err
+	}
+	return os.FileMode(mode), nil
+}
+
 // FileWriter can write logs to files. By default, log files
 // are rotated ("rolled") when they get large, and old log
 // files get deleted, to ensure that the process does not
@@ -43,7 +81,7 @@ type FileWriter struct {
 
 	// The file permissions mode.
 	// 0600 by default.
-	Mode os.FileMode `json:"mode,omitempty"`
+	Mode FileMode `json:"mode,omitempty"`
 
 	// Roll toggles log rolling or rotation, which is
 	// enabled by default.
@@ -124,7 +162,7 @@ func (fw FileWriter) OpenWriter() (io.WriteCloser, error) {
 			fw.RollKeepDays = 90
 		}
 
-		f_tmp, _ := os.OpenFile(fw.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, fw.Mode)
+		f_tmp, _ := os.OpenFile(fw.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, os.FileMode(fw.Mode))
 		f_tmp.Close()
 
 		return &lumberjack.Logger{
@@ -138,7 +176,7 @@ func (fw FileWriter) OpenWriter() (io.WriteCloser, error) {
 	}
 
 	// otherwise just open a regular file
-	return os.OpenFile(fw.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, fw.Mode)
+	return os.OpenFile(fw.Filename, os.O_WRONLY|os.O_APPEND|os.O_CREATE, os.FileMode(fw.Mode))
 }
 
 // UnmarshalCaddyfile sets up the module from Caddyfile tokens. Syntax:
@@ -182,11 +220,11 @@ func (fw *FileWriter) UnmarshalCaddyfile(d *caddyfile.Dispenser) error {
 			if !d.AllArgs(&modeStr) {
 				return d.ArgErr()
 			}
-			mode, err := strconv.ParseUint(modeStr, 0, 32)
+			mode, err := ParseFileMode(modeStr)
 			if err != nil {
 				return d.Errf("parsing mode: %v", err)
 			}
-			fw.Mode = os.FileMode(mode)
+			fw.Mode = FileMode(mode)
 
 		case "roll_disabled":
 			var f bool

modules/logging/filewriter_test.go

@@ -15,6 +15,7 @@
 package logging
 
 import (
+	"encoding/json"
 	"os"
 	"path"
 	"testing"
@@ -107,7 +108,7 @@ func TestFileRotationPreserveMode(t *testing.T) {
 	fpath := path.Join(dir, "test.log")
 
 	roll := true
-	mode := os.FileMode(0o640)
+	mode := FileMode(0o640)
 	fw := FileWriter{
 		Filename:   fpath,
 		Mode:       mode,
@@ -144,7 +145,7 @@ func TestFileRotationPreserveMode(t *testing.T) {
 		t.Fatalf("failed to check file permissions: %v", err)
 	}
 
-	if st.Mode() != mode {
+	if st.Mode() != os.FileMode(mode) {
 		t.Errorf("file mode is %v, want %v", st.Mode(), mode)
 	}
 
@@ -157,7 +158,7 @@ func TestFileRotationPreserveMode(t *testing.T) {
 		t.Fatalf("failed to check file permissions: %v", err)
 	}
 
-	if st.Mode() != mode {
+	if st.Mode() != os.FileMode(mode) {
 		t.Errorf("file mode is %v, want %v", st.Mode(), mode)
 	}
 }
@@ -181,6 +182,42 @@ file test.log {
 			},
 			wantErr: false,
 		},
+		{
+			name: "set mode 3 digits",
+			d: caddyfile.NewTestDispenser(`
+file test.log {
+	mode 666
+}
+`),
+			fw: FileWriter{
+				Mode: 0o666,
+			},
+			wantErr: false,
+		},
+		{
+			name: "set mode 2 digits",
+			d: caddyfile.NewTestDispenser(`
+file test.log {
+	mode 66
+}
+`),
+			fw: FileWriter{
+				Mode: 0o066,
+			},
+			wantErr: false,
+		},
+		{
+			name: "set mode 1 digits",
+			d: caddyfile.NewTestDispenser(`
+file test.log {
+	mode 6
+}
+`),
+			fw: FileWriter{
+				Mode: 0o006,
+			},
+			wantErr: false,
+		},
 		{
 			name: "invalid mode",
 			d: caddyfile.NewTestDispenser(`
@@ -205,3 +242,57 @@ file test.log {
 		})
 	}
 }
+
+func TestFileModeJSON(t *testing.T) {
+	tests := []struct {
+		name    string
+		config  string
+		fw      FileWriter
+		wantErr bool
+	}{
+		{
+			name: "set mode",
+			config: `
+{
+	"mode": "0666"
+}
+`,
+			fw: FileWriter{
+				Mode: 0o666,
+			},
+			wantErr: false,
+		},
+		{
+			name: "set mode invalid value",
+			config: `
+{
+	"mode": "0x666"
+}
+`,
+			fw:      FileWriter{},
+			wantErr: true,
+		},
+		{
+			name: "set mode invalid string",
+			config: `
+{
+	"mode": 777
+}
+`,
+			fw:      FileWriter{},
+			wantErr: true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			fw := &FileWriter{}
+			if err := json.Unmarshal([]byte(tt.config), fw); (err != nil) != tt.wantErr {
+				t.Fatalf("UnmarshalJSON() error = %v, want %v", err, tt.wantErr)
+			}
+			if fw.Mode != tt.fw.Mode {
+				t.Errorf("got mode %v, want %v", fw.Mode, tt.fw.Mode)
+			}
+		})
+	}
+}