eleksir/backer
0
Fork 0
Code Pull Requests Releases Activity

Implemented tar+bz2 compression + unit tests for it.

Browse Source
This commit is contained in:
eleksir
2026-03-27 21:28:27 +03:00
parent 05c9eb6669
commit 5226688836
12 changed files with 247 additions and 29 deletions
Download Patch File Download Diff File Expand all files Collapse all files

4
AGENTS.md
View File

@@ -182,6 +182,7 @@ Config is JSON (HJSON with comments supported). Default path depends on OS:
| compression_level | `9` | Gzip level (1-9) |
| exclude_patterns | `[]` | Regex patterns to exclude from backup |
| filename_prefix | `backup` | Prefix for backup filename in Content-Disposition header |
| compression_algorithm | `gzip` | Compression algorithm: gzip or bzip2 |
## Architecture & Key Patterns
@@ -277,5 +278,4 @@ Init scripts provided in `contrib/`:
## TODO / Roadmap
See `TODO.org` for current backlog:
- Consider alternative compression algorithms (bz2, xz, lzo, lz4)
See `TODO.org` for current backlog.

1
README.md
View File

@@ -57,6 +57,7 @@ AI suggests to fill this section with useful information, despite that all optio
| compression_level | 9 | Gzip compression level for tar.gz archives. | 1 (fastest) to 9 (best compression). Higher values produce smaller files but take longer to compress. |
| exclude_patterns | [] | Regex patterns to exclude from backup. | E.g., `[".*\\.tmp$", "/node_modules/"]`. Files matching any pattern are skipped. |
| filename_prefix | "backup" | Prefix for backup filename in Content-Disposition header. | E.g., "mybackup" produces `mybackup-20260325-092341.tar.gz`. |
| compression_algorithm | "gzip" | Compression algorithm for archive. | Options: "gzip", "bzip2". Gzip is faster, bzip2 produces smaller files. |
## Best practices

7
TODO.org
View File

@@ -5,9 +5,10 @@
* TODO Backer Tasks
** TODO Consider different compression algorithms
- [ ] Evaluate alternatives to gzip: bz2, xz, lzo, lz4
- [ ] lz4 for speed, xz for better compression
- [ ] Add compression_algorithm config option
- [X] Evaluate alternatives to gzip: bz2, xz, lzo, lz4
- CANCELLED lzo. It has cgo implementaion which depends in liblzo, and native lid that does not support streaming.
- [X] Implemented bzip2 as alternative (pure Go, via github.com/dsnet/compress)
- [X] Add compression_algorithm config option
** DONE Configurable filename prefix
- [X] Move "backup" prefix to config (currently hardcoded in newServer.go)

5
data/config_example.json
View File

@@ -45,5 +45,8 @@
"exclude_patterns": [],
/* Prefix for backup filename in Content-Disposition header. */
"filename_prefix": "backup"
"filename_prefix": "backup",
/* Compression algorithm: gzip or bzip2. */
"compression_algorithm": "gzip"
}

2
go.mod
View File

@@ -3,3 +3,5 @@ module backer
go 1.25
require github.com/hjson/hjson-go v3.3.0+incompatible
require github.com/dsnet/compress v0.0.1 // indirect

6
go.sum
View File

@@ -1,2 +1,8 @@
github.com/dsnet/compress v0.0.1 h1:PlZu0n3Tuv04TzpfPbrnI0HW/YwodEXDS+oPKahKF0Q=
github.com/dsnet/compress v0.0.1/go.mod h1:Aw8dCMJ7RioblQeTqt88akK31OvO8Dhf5JflhBbQEHo=
github.com/dsnet/golib v0.0.0-20171103203638-1ea166775780/go.mod h1:Lj+Z9rebOhdfkVLjJ8T6VcRQv3SXugXy999NBtR9aFY=
github.com/hjson/hjson-go v3.3.0+incompatible h1:Rqr+Ya+0aCJMjaE4s8E9YKvuJLuLVpEvz4ONum52vnI=
github.com/hjson/hjson-go v3.3.0+incompatible/go.mod h1:qsetwF8NlsTsOTwZTApNlTCerV+b2GjYRRcIk4JMFio=
github.com/klauspost/compress v1.4.1/go.mod h1:RyIbtBH6LamlWaDj8nUwkbUhJ87Yi3uG0guNDohfE1A=
github.com/klauspost/cpuid v1.2.0/go.mod h1:Pj4uuM528wm8OyEC2QMXAi2YiTZ96dNQPGgoMS4s3ek=
github.com/ulikunitz/xz v0.5.6/go.mod h1:2bypXElzHzzJZwzH67Y6wb67pO62Rzfn7BSiF4ABRW8=

11
internal/backer/loadConfig.go
View File

@@ -135,6 +135,17 @@ func LoadConfig(path string) error {
log.Warnf("Config option filename_prefix is not set, fallback to %s", C.FilenamePrefix)
}
// CompressionAlgorithm: default and validate.
if C.CompressionAlgorithm == "" {
C.CompressionAlgorithm = "gzip"
log.Warnf("Config option compression_algorithm is not set, fallback to %s", C.CompressionAlgorithm)
}
if C.CompressionAlgorithm != "gzip" && C.CompressionAlgorithm != "bzip2" {
return fmt.Errorf("Compression_algorithm must be gzip or bzip2, got %s", C.CompressionAlgorithm)
}
// Compile exclude patterns.
excludePatterns = make([]*regexp.Regexp, 0, len(C.ExcludePatterns))

42
internal/backer/loadConfig_test.go
View File

@@ -226,6 +226,48 @@ func TestLoadConfigDefaultValues(t *testing.T) {
if C.FilenamePrefix != "backup" {
t.Errorf("C.FilenamePrefix should default to backup, got %s", C.FilenamePrefix)
}
if C.CompressionAlgorithm != "gzip" {
t.Errorf("C.CompressionAlgorithm should default to gzip, got %s", C.CompressionAlgorithm)
}
}
// TestLoadConfigCompressionAlgorithmBzip2 tests bzip2 compression algorithm.
func TestLoadConfigCompressionAlgorithmBzip2(t *testing.T) {
config := `{
"user": "test",
"password": "test",
"directories": ["../../test_data/test1/foo"],
"nohttps": true,
"compression_algorithm": "bzip2"
}`
tmpFile := writeTempConfig(t, config)
err := LoadConfig(tmpFile)
if err != nil {
t.Errorf("Expected no error, got %v", err)
}
if C.CompressionAlgorithm != "bzip2" {
t.Errorf("C.CompressionAlgorithm should be bzip2, got %s", C.CompressionAlgorithm)
}
}
// TestLoadConfigCompressionAlgorithmInvalid tests invalid compression algorithm.
func TestLoadConfigCompressionAlgorithmInvalid(t *testing.T) {
config := `{
"user": "test",
"password": "test",
"directories": ["../../test_data/test1/foo"],
"nohttps": true,
"compression_algorithm": "invalid"
}`
tmpFile := writeTempConfig(t, config)
err := LoadConfig(tmpFile)
if err == nil {
t.Error("Expected error for invalid compression algorithm, got nil")
}
}
// writeTempConfig is a helper to write a temp config file for testing.

21
internal/backer/newServer.go
View File

@@ -73,21 +73,32 @@ func NewServer(configPath string) (*http.Server, error) {
return
}
tarGz := CreateTarGzStream(ctx, files)
var (
archive io.ReadCloser
extension string
)
if C.CompressionAlgorithm == "bzip2" {
archive = CreateTarBzip2Stream(ctx, files)
extension = "tar.bz2"
} else {
archive = CreateTarGzStream(ctx, files)
extension = "tar.gz"
}
defer func() {
if err := tarGz.Close(); err != nil {
log.Errorf("Failed to close tar.gz reader: %v", err)
if err := archive.Close(); err != nil {
log.Errorf("Failed to close archive reader: %v", err)
}
}()
timestamp := time.Now().Format("20060102-150405")
filename := fmt.Sprintf("%s-%s.tar.gz", C.FilenamePrefix, timestamp)
filename := fmt.Sprintf("%s-%s.%s", C.FilenamePrefix, timestamp, extension)
w.Header().Set("Content-Disposition", "attachment; filename="+filename)
w.Header().Set("Content-Type", "application/octet-stream")
bytesWritten, err := io.Copy(w, tarGz)
bytesWritten, err := io.Copy(w, archive)
duration := time.Since(backupStart)
if err != nil {

31
internal/backer/types.go
View File

@@ -3,21 +3,22 @@ package backer
type (
// Config main config struct.
Config struct {
Address string `json:"address"`
Port int `json:"port"`
Cert string `json:"cert"`
Key string `json:"key"`
NoHTTPS bool `json:"nohttps"`
Location string `json:"location"`
User string `json:"user"`
Password string `json:"password"`
Log string `json:"log"`
LogLevel string `json:"loglevel"`
Directories []string `json:"directories"`
BackupTimeout int `json:"backup_timeout"` // Timeout in minutes for backup streaming.
CompressionLevel int `json:"compression_level"` // Gzip compression level (1-9, default 9).
ExcludePatterns []string `json:"exclude_patterns"` // Regex patterns to exclude from backup.
FilenamePrefix string `json:"filename_prefix"` // Prefix for backup filename (default: "backup").
Address string `json:"address"`
Port int `json:"port"`
Cert string `json:"cert"`
Key string `json:"key"`
NoHTTPS bool `json:"nohttps"`
Location string `json:"location"`
User string `json:"user"`
Password string `json:"password"`
Log string `json:"log"`
LogLevel string `json:"loglevel"`
Directories []string `json:"directories"`
BackupTimeout int `json:"backup_timeout"` // Timeout in minutes for backup streaming.
CompressionLevel int `json:"compression_level"` // Gzip compression level (1-9, default 9).
ExcludePatterns []string `json:"exclude_patterns"` // Regex patterns to exclude from backup.
FilenamePrefix string `json:"filename_prefix"` // Prefix for backup filename (default: "backup").
CompressionAlgorithm string `json:"compression_algorithm"` // Compression algorithm: gzip or bzip2 (default: "gzip").
}
)

141
internal/backer/utils.go
View File

@@ -11,6 +11,8 @@ import (
"strings"
"backer/internal/log"
"github.com/dsnet/compress/bzip2"
)
// CreateTarGzStream takes a list of files and returns a reader that reads from a tar archive containing these files.
@@ -162,6 +164,145 @@ func CreateTarGzStream(ctx context.Context, filepaths []string) io.ReadCloser {
return pr
}
// CreateTarBzip2Stream takes a list of files and returns a reader that reads from a bzip2-compressed tar archive.
func CreateTarBzip2Stream(ctx context.Context, filepaths []string) io.ReadCloser {
pr, pw := io.Pipe()
go func() {
var pipeErr error
closePipeWithError := func(err error) {
if pipeErr != nil {
return
}
pipeErr = err
pw.CloseWithError(err)
}
defer func() {
if pipeErr == nil {
pw.Close()
}
}()
bw, err := bzip2.NewWriter(pw, nil)
if err != nil {
closePipeWithError(fmt.Errorf("bzip2 writer error: %w", err))
return
}
defer func() {
if pipeErr == nil {
if err := bw.Close(); err != nil {
if !isPipeClosedError(err) {
log.Errorf("Failed to close bzip2 writer: %v", err)
}
}
}
}()
tw := tar.NewWriter(bw)
defer func() {
if pipeErr == nil {
if err := tw.Close(); err != nil {
if !isPipeClosedError(err) {
log.Errorf("Failed to close tar writer: %v", err)
}
}
}
}()
for _, fpath := range filepaths {
var (
err error
linkTarget string
)
select {
case <-ctx.Done():
closePipeWithError(ctx.Err())
return
default:
}
log.Debugf("Adding file: %s", fpath)
st, err := os.Lstat(fpath)
if err != nil {
log.Warnf("Skipping %s: %v", fpath, err)
continue
}
if st.Mode()&os.ModeSymlink != 0 {
linkTarget, err = os.Readlink(fpath)
if err != nil {
log.Warnf("Skipping %s: readlink failed: %v", fpath, err)
continue
}
}
if st.Mode()&os.ModeSocket != 0 {
log.Debugf("Skipping socket: %s", fpath)
continue
}
header, err := tar.FileInfoHeader(st, linkTarget)
if err != nil {
log.Warnf("Skipping %s: tar header failed: %v", fpath, err)
continue
}
header.Format = tar.FormatGNU
header.Name = strings.TrimPrefix(filepath.ToSlash(filepath.Clean(fpath)), "/")
mode := st.Mode()
if err := writeWithContext(ctx, func() error {
return tw.WriteHeader(header)
}); err != nil {
closePipeWithError(err)
return
}
if mode.IsRegular() {
f, err := os.Open(fpath)
if err != nil {
log.Warnf("Skipping %s: open failed: %v", fpath, err)
continue
}
err = copyWithContext(ctx, tw, f)
if e := f.Close(); e != nil {
log.Warnf("Failed to close file %s: %v", fpath, e)
}
if err != nil {
log.Warnf("Skipping %s: copy failed: %v", fpath, err)
continue
}
}
}
}()
return pr
}
// isPipeClosedError checks if the error is due to a closed pipe.
func isPipeClosedError(err error) bool {
if err == nil {

5
llms.txt
View File

@@ -62,6 +62,7 @@ curl -u user:pass https://server:8086/archive -o backup.tar.gz
| compression_level | 9 | Gzip level (1-9) |
| exclude_patterns | [] | Regex patterns to exclude from backup |
| filename_prefix | backup | Prefix for backup filename in Content-Disposition header |
| compression_algorithm | gzip | Compression algorithm (gzip or bzip2) |
## Key Patterns
@@ -203,6 +204,4 @@ var version = "dev" // overridden by: -X main.version=$(VERSION)
```
## Known Issues / TODO
See TODO.org for current backlog:
- Consider different compression algorithms (bz2, xz, lzo, lz4)
- Consider configurable filename prefix for content-disposition
See TODO.org for current backlog.