1 files changed, 104 insertions, 0 deletions
diff --git a/src/go/collectors/go.d.plugin/logger/logger.go b/src/go/collectors/go.d.plugin/logger/logger.go
new file mode 100644
index 000000000..bccf3f0d6
--- /dev/null
+++ b/src/go/collectors/go.d.plugin/logger/logger.go
@@ -0,0 +1,104 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+package logger
+
+import (
+	"context"
+	"fmt"
+	"log/slog"
+	"os"
+	"strconv"
+	"strings"
+	"sync/atomic"
+	"syscall"
+
+	"github.com/netdata/netdata/go/go.d.plugin/agent/executable"
+
+	"github.com/mattn/go-isatty"
+)
+
+var isTerm = isatty.IsTerminal(os.Stderr.Fd())
+
+var isJournal = isStderrConnectedToJournal()
+
+var pluginAttr = slog.String("plugin", executable.Name)
+
+func New() *Logger {
+	if isTerm {
+		// skip 2 slog pkg calls, 2 this pkg calls
+		return &Logger{sl: slog.New(withCallDepth(4, newTerminalHandler()))}
+	}
+	return &Logger{sl: slog.New(newTextHandler()).With(pluginAttr)}
+}
+
+type Logger struct {
+	muted atomic.Bool
+	sl    *slog.Logger
+}
+
+func (l *Logger) Error(a ...any)                   { l.log(slog.LevelError, fmt.Sprint(a...)) }
+func (l *Logger) Warning(a ...any)                 { l.log(slog.LevelWarn, fmt.Sprint(a...)) }
+func (l *Logger) Notice(a ...any)                  { l.log(levelNotice, fmt.Sprint(a...)) }
+func (l *Logger) Info(a ...any)                    { l.log(slog.LevelInfo, fmt.Sprint(a...)) }
+func (l *Logger) Debug(a ...any)                   { l.log(slog.LevelDebug, fmt.Sprint(a...)) }
+func (l *Logger) Errorf(format string, a ...any)   { l.log(slog.LevelError, fmt.Sprintf(format, a...)) }
+func (l *Logger) Warningf(format string, a ...any) { l.log(slog.LevelWarn, fmt.Sprintf(format, a...)) }
+func (l *Logger) Noticef(format string, a ...any)  { l.log(levelNotice, fmt.Sprintf(format, a...)) }
+func (l *Logger) Infof(format string, a ...any)    { l.log(slog.LevelInfo, fmt.Sprintf(format, a...)) }
+func (l *Logger) Debugf(format string, a ...any)   { l.log(slog.LevelDebug, fmt.Sprintf(format, a...)) }
+func (l *Logger) Mute()                            { l.mute(true) }
+func (l *Logger) Unmute()                          { l.mute(false) }
+
+func (l *Logger) With(args ...any) *Logger {
+	if l.isNil() {
+		return &Logger{sl: New().sl.With(args...)}
+	}
+
+	ll := &Logger{sl: l.sl.With(args...)}
+	ll.muted.Store(l.muted.Load())
+
+	return ll
+}
+
+func (l *Logger) log(level slog.Level, msg string) {
+	if l.isNil() {
+		nilLogger.sl.Log(context.Background(), level, msg)
+		return
+	}
+
+	if !l.muted.Load() {
+		l.sl.Log(context.Background(), level, msg)
+	}
+}
+
+func (l *Logger) mute(v bool) {
+	if l.isNil() || isTerm && Level.Enabled(slog.LevelDebug) {
+		return
+	}
+	l.muted.Store(v)
+}
+
+func (l *Logger) isNil() bool { return l == nil || l.sl == nil }
+
+var nilLogger = New()
+
+func isStderrConnectedToJournal() bool {
+	stream := os.Getenv("JOURNAL_STREAM")
+	if stream == "" {
+		return false
+	}
+
+	idx := strings.IndexByte(stream, ':')
+	if idx <= 0 {
+		return false
+	}
+
+	dev, ino := stream[:idx], stream[idx+1:]
+
+	var stat syscall.Stat_t
+	if err := syscall.Fstat(int(os.Stderr.Fd()), &stat); err != nil {
+		return false
+	}
+
+	return dev == strconv.Itoa(int(stat.Dev)) && ino == strconv.FormatUint(stat.Ino, 10)
+}