feat(logger): CST timezone logging + journald auto-detect (#1021)

pkg/logger/logger.go

@@ -6,22 +6,75 @@
 package logger
 
 import (
+	"os"
+	"time"
+
 	"github.com/sirupsen/logrus"
 	prefixed "github.com/x-cray/logrus-prefixed-formatter"
 	"gopkg.in/natefinch/lumberjack.v2"
 )
 
+// cstLocation is the CST (UTC+8) location used for log timestamps.
+// Initialized once at package init with a graceful fallback for systems
+// without tzdata (e.g., minimal OpenWrt/ImmortalWrt builds).
+var cstLocation *time.Location
+
+func init() {
+	if loc, err := time.LoadLocation("Asia/Shanghai"); err == nil {
+		cstLocation = loc
+	} else {
+		cstLocation = time.FixedZone("CST", 8*3600)
+	}
+}
+
+// isJournaldStream returns true if dae's stdout/stderr is captured by systemd's
+// journald.  Systemd sets the JOURNAL_STREAM environment variable for each
+// service's standard streams (value is "device:inode").  When true we suppress
+// dae's own timestamp to avoid the redundant "journald prefix + CST timestamp"
+// double-prefix that PR #1021 introduced by removing --disable-timestamp from
+// dae.service.
+func isJournaldStream() bool {
+	return os.Getenv("JOURNAL_STREAM") != ""
+}
+
+// cstFormatter wraps prefixed.TextFormatter to use CST timezone for timestamps
+// without modifying the global time.Local, which would affect unrelated code.
+type cstFormatter struct {
+	*prefixed.TextFormatter
+}
+
+// Format overrides the timestamp formatting to use CST timezone.
+func (f *cstFormatter) Format(entry *logrus.Entry) ([]byte, error) {
+	// Create a copy of the entry to avoid modifying the shared entry object
+	if !f.DisableTimestamp && entry.Time != (time.Time{}) {
+		modifiedEntry := *entry
+		modifiedEntry.Time = entry.Time.In(cstLocation)
+		return f.TextFormatter.Format(&modifiedEntry)
+	}
+	return f.TextFormatter.Format(entry)
+}
+
 func SetLogger(log *logrus.Logger, logLevel string, disableTimestamp bool, logFileOpt *lumberjack.Logger) {
 	level, err := logrus.ParseLevel(logLevel)
 	if err != nil {
 		level = logrus.InfoLevel
 	}
 
 	log.SetLevel(level)
-	log.SetFormatter(&prefixed.TextFormatter{
-		DisableTimestamp: disableTimestamp,
-		FullTimestamp:    true,
-		TimestampFormat:  "Jan 02 15:04:05",
+	// Auto-disable timestamp under journald to avoid double prefix.
+	// When writing to a logfile we always emit the CST timestamp (the file
+	// needs a self-describing timestamp).  --disable-timestamp still forces
+	// suppression for callers that explicitly want it.
+	if !disableTimestamp && isJournaldStream() && logFileOpt == nil {
+		disableTimestamp = true
+	}
+	log.SetFormatter(&cstFormatter{
+		TextFormatter: &prefixed.TextFormatter{
+			DisableTimestamp: disableTimestamp,
+			FullTimestamp:    true,
+			ForceFormatting:  true,
+			TimestampFormat:  "2006-01-02 15:04:05",
+		},
 	})
 	if logFileOpt != nil {
 		log.SetOutput(logFileOpt)