build+mod: add zstd compressor support

Author: jharveyb

build/logrotator.go

@@ -1,6 +1,7 @@
 package build
 
 import (
+	"compress/gzip"
 	"fmt"
 	"io"
 	"os"
@@ -9,6 +10,7 @@ import (
 
 	"github.com/btcsuite/btclog"
 	"github.com/jrick/logrotate/rotator"
+	"github.com/klauspost/compress/zstd"
 )
 
 // RotatingLogWriter is a wrapper around the LogWriter that supports log file
@@ -58,8 +60,8 @@ func (r *RotatingLogWriter) RegisterSubLogger(subsystem string,
 // InitLogRotator initializes the log file rotator to write logs to logFile and
 // create roll files in the same directory. It should be called as early on
 // startup and possible and must be closed on shutdown by calling `Close`.
-func (r *RotatingLogWriter) InitLogRotator(logFile string, maxLogFileSize int,
-	maxLogFiles int) error {
+func (r *RotatingLogWriter) InitLogRotator(logFile, logCompressor string,
+	maxLogFileSize int, maxLogFiles int) error {
 
 	logDir, _ := filepath.Split(logFile)
 	err := os.MkdirAll(logDir, 0700)
@@ -73,6 +75,27 @@ func (r *RotatingLogWriter) InitLogRotator(logFile string, maxLogFileSize int,
 		return fmt.Errorf("failed to create file rotator: %w", err)
 	}
 
+	// Reject unknown compressors.
+	if !SuportedLogCompressor(logCompressor) {
+		return fmt.Errorf("unknown log compressor: %v", logCompressor)
+	}
+
+	var c rotator.Compressor
+	switch logCompressor {
+	case Gzip:
+		c = gzip.NewWriter(nil)
+
+	case Zstd:
+		c, err = zstd.NewWriter(nil)
+		if err != nil {
+			return fmt.Errorf("failed to create zstd compressor: "+
+				"%w", err)
+		}
+	}
+
+	// Apply the compressor and its file suffix to the log rotator.
+	r.logRotator.SetCompressor(c, logCompressors[logCompressor])
+
 	// Run rotator as a goroutine now but make sure we catch any errors
 	// that happen in case something with the rotation goes wrong during
 	// runtime (like running out of disk space or not being allowed to

config.go

@@ -1458,7 +1458,7 @@ func ValidateConfig(cfg Config, interceptor signal.Interceptor, fileParser,
 	SetupLoggers(cfg.LogWriter, interceptor)
 	err = cfg.LogWriter.InitLogRotator(
 		filepath.Join(cfg.LogDir, defaultLogFilename),
-		cfg.MaxLogFileSize, cfg.MaxLogFiles,
+		cfg.LogCompressor, cfg.MaxLogFileSize, cfg.MaxLogFiles,
 	)
 	if err != nil {
 		str := "log rotation setup failed: %v"

go.mod

@@ -118,6 +118,7 @@ require (
 	github.com/json-iterator/go v1.1.11 // indirect
 	github.com/juju/loggo v0.0.0-20210728185423-eebad3a902c4 // indirect
 	github.com/juju/testing v0.0.0-20220203020004-a0ff61f03494 // indirect
+	github.com/klauspost/compress v1.17.9
 	github.com/lib/pq v1.10.9 // indirect
 	github.com/lightninglabs/gozmq v0.0.0-20191113021534-d20a764486bf // indirect
 	github.com/mattn/go-isatty v0.0.20 // indirect

go.sum

@@ -419,6 +419,8 @@ github.com/kisielk/gotool v1.0.0/go.mod h1:XhKaO+MFFWcvkIS/tQcRk01m1F5IRFswLeQ+o
 github.com/kkdai/bstream v0.0.0-20161212061736-f391b8402d23/go.mod h1:J+Gs4SYgM6CZQHDETBtE9HaSEkGmuNXF86RwHhHUvq4=
 github.com/kkdai/bstream v1.0.0 h1:Se5gHwgp2VT2uHfDrkbbgbgEvV9cimLELwrPJctSjg8=
 github.com/kkdai/bstream v1.0.0/go.mod h1:FDnDOHt5Yx4p3FaHcioFT0QjDOtgUpvjeZqAs+NVZZA=
+github.com/klauspost/compress v1.17.9 h1:6KIumPrER1LHsvBVuDa0r5xaG0Es51mhhB9BQB2qeMA=
+github.com/klauspost/compress v1.17.9/go.mod h1:Di0epgTjJY877eYKx5yC51cX2A2Vl2ibi7bDH9ttBbw=
 github.com/konsorten/go-windows-terminal-sequences v1.0.1/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.2/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=
 github.com/konsorten/go-windows-terminal-sequences v1.0.3/go.mod h1:T0+1ngSBFLxvqU3pZ+m/2kptfBszLMUkC4ZK/EgS/cQ=