From 733440cf3dd5f2dc2e27cc1483bf139eeb13cefd Mon Sep 17 00:00:00 2001
From: Kegan Dougal <kegan@matrix.org>
Date: Tue, 1 Nov 2016 14:22:37 +0000
Subject: [PATCH] GZip logs by default

---
 src/github.com/matrix-org/go-neb/goneb.go     |  2 +-
 vendor/manifest                               |  4 +-
 .../github.com/matrix-org/dugong/fshook.go    | 46 +++++++++++++++++--
 3 files changed, 45 insertions(+), 7 deletions(-)

diff --git a/src/github.com/matrix-org/go-neb/goneb.go b/src/github.com/matrix-org/go-neb/goneb.go
index 6f1e75f..eef917f 100644
--- a/src/github.com/matrix-org/go-neb/goneb.go
+++ b/src/github.com/matrix-org/go-neb/goneb.go
@@ -224,7 +224,7 @@ func main() {
 			filepath.Join(e.LogDir, "info.log"),
 			filepath.Join(e.LogDir, "warn.log"),
 			filepath.Join(e.LogDir, "error.log"),
-			nil, &dugong.DailyRotationSchedule{},
+			nil, &dugong.DailyRotationSchedule{GZip: true},
 		))
 	}
 
diff --git a/vendor/manifest b/vendor/manifest
index 0f2e1da..7ef95ff 100644
--- a/vendor/manifest
+++ b/vendor/manifest
@@ -132,7 +132,7 @@
 		{
 			"importpath": "github.com/matrix-org/dugong",
 			"repository": "https://github.com/matrix-org/dugong",
-			"revision": "07b01e0bea3c53627f5a3fc9c5f36ad145a4b086",
+			"revision": "193b8f88e381d12f2d53023fba25e43fc81dc5ac",
 			"branch": "master"
 		},
 		{
@@ -314,4 +314,4 @@
 			"branch": "v2"
 		}
 	]
-}
+}
\ No newline at end of file
diff --git a/vendor/src/github.com/matrix-org/dugong/fshook.go b/vendor/src/github.com/matrix-org/dugong/fshook.go
index 8081dc1..be539ab 100644
--- a/vendor/src/github.com/matrix-org/dugong/fshook.go
+++ b/vendor/src/github.com/matrix-org/dugong/fshook.go
@@ -1,9 +1,12 @@
 package dugong
 
 import (
+	"compress/gzip"
 	"fmt"
 	log "github.com/Sirupsen/logrus"
+	"io"
 	"os"
+	"path/filepath"
 	"sync/atomic"
 	"time"
 )
@@ -13,6 +16,8 @@ type RotationScheduler interface {
 	// ShouldRotate returns true if the file should be rotated. The suffix to apply
 	// to the filename is returned as the 2nd arg.
 	ShouldRotate() (bool, string)
+	// ShouldGZip returns true if the file should be gzipped when it is rotated.
+	ShouldGZip() bool
 }
 
 // DailyRotationSchedule rotates log files daily. Logs are only rotated
@@ -20,6 +25,7 @@ type RotationScheduler interface {
 // the process on Day 4 then stop it and start it on Day 7, no rotation will
 // occur when the process starts.
 type DailyRotationSchedule struct {
+	GZip        bool
 	rotateAfter *time.Time
 }
 
@@ -53,6 +59,10 @@ func (rs *DailyRotationSchedule) ShouldRotate() (bool, string) {
 	return false, ""
 }
 
+func (rs *DailyRotationSchedule) ShouldGZip() bool {
+	return rs.GZip
+}
+
 // NewFSHook makes a logging hook that writes formatted
 // log entries to info, warn and error log files. Each log file
 // contains the messages with that severity or higher. If a formatter is
@@ -107,7 +117,7 @@ func (hook *fsHook) writeEntry(entry *log.Entry) error {
 
 	if hook.scheduler != nil {
 		if should, suffix := hook.scheduler.ShouldRotate(); should {
-			if err := hook.rotate(suffix); err != nil {
+			if err := hook.rotate(suffix, hook.scheduler.ShouldGZip()); err != nil {
 				return err
 			}
 		}
@@ -150,13 +160,19 @@ func (hook *fsHook) Levels() []log.Level {
 // This requires no locking as the goroutine calling this is the same
 // one which does the logging. Since we don't hold open a handle to the
 // file when writing, a simple Rename is all that is required.
-func (hook *fsHook) rotate(suffix string) error {
+func (hook *fsHook) rotate(suffix string, gzip bool) error {
 	for _, fpath := range []string{hook.errorPath, hook.warnPath, hook.infoPath} {
-		if err := os.Rename(fpath, fpath+suffix); err != nil {
+		logFilePath := fpath + suffix
+		if err := os.Rename(fpath, logFilePath); err != nil {
 			// e.g. because there were no errors in error.log for this day
 			fmt.Fprintf(os.Stderr, "Error rotating file %s: %v\n", fpath, err)
+			continue // don't try to gzip if we failed to rotate
+		}
+		if gzip {
+			if err := gzipFile(logFilePath); err != nil {
+				fmt.Fprintf(os.Stderr, "Failed to gzip file %s: %v\n", logFilePath, err)
+			}
 		}
-
 	}
 	return nil
 }
@@ -170,3 +186,25 @@ func logToFile(path string, msg []byte) error {
 	_, err = fd.Write(msg)
 	return err
 }
+
+func gzipFile(fpath string) error {
+	reader, err := os.Open(fpath)
+	if err != nil {
+		return err
+	}
+
+	filename := filepath.Base(fpath)
+	target := filepath.Join(filepath.Dir(fpath), filename+".gz")
+	writer, err := os.Create(target)
+	if err != nil {
+		return err
+	}
+	defer writer.Close()
+
+	archiver := gzip.NewWriter(writer)
+	archiver.Name = filename
+	defer archiver.Close()
+
+	_, err = io.Copy(archiver, reader)
+	return err
+}