From 00d3e6d532f8c875c50530881817d18df5845505 Mon Sep 17 00:00:00 2001
From: Markus Ongyerth <ongyerth@google.com>
Date: Tue, 9 Sep 2025 09:47:22 +0000
Subject: [PATCH 1/2] Add a way to configure the loglevel

The flagset is supported by
* stdlib
* pflags
* cobra (via pflags)

This way we also avoid magic things just happening, but can expose a consistent cmdline API
---
 multiwriter.go | 31 ++++++++++++++++++++++++++++++-
 1 file changed, 30 insertions(+), 1 deletion(-)

diff --git a/multiwriter.go b/multiwriter.go
index 4d8b1dc..4dd2c71 100644
--- a/multiwriter.go
+++ b/multiwriter.go
@@ -15,12 +15,41 @@
 package ilog
 
 import (
+	"flag"
 	"fmt"
 	"io"
 	"log/slog"
 	"os"
+	"strings"
 )
 
+var (
+	level slog.Level = slog.LevelInfo
+)
+
+func logLevelFromString(str string) (slog.Level, error) {
+	switch str {
+	case "debug":
+		return slog.LevelDebug, nil
+	case "info":
+		return slog.LevelInfo, nil
+	case "warn":
+		return slog.LevelWarn, nil
+	case "error":
+		return slog.LevelError, nil
+  default:
+		return slog.LevelInfo, fmt.Errorf("unknown log level %s", str)
+	}
+}
+
+func SetupFlags(fs *flag.FlagSet) {
+	fs.Func("log-level", "Sets the log level. Allowed values are: debug, info, warn, error", func(str string) error {
+		var err error
+		level, err = logLevelFromString(strings.ToLower(str))
+		return err
+	})
+}
+
 type multiCloser struct {
 	closer []io.Closer
 }
@@ -55,7 +84,7 @@ func Setup(fs ...string) (io.Closer, error) {
 		mc.closer = append(mc.closer, w)
 		writer = append(writer, w)
 	}
-	nh := NewLogHandler(slog.LevelInfo, io.MultiWriter(writer...))
+	nh := NewLogHandler(level, io.MultiWriter(writer...))
 	slog.SetDefault(slog.New(nh))
 	return &mc, nil
 }

From 1888844e4e92414b3b6f27a11aaec2ebd574a057 Mon Sep 17 00:00:00 2001
From: Markus Ongyerth <ongyerth@google.com>
Date: Tue, 9 Sep 2025 09:56:52 +0000
Subject: [PATCH 2/2] Add 'warning' as allowed flag value

---
 multiwriter.go | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/multiwriter.go b/multiwriter.go
index 4dd2c71..998f560 100644
--- a/multiwriter.go
+++ b/multiwriter.go
@@ -33,11 +33,11 @@ func logLevelFromString(str string) (slog.Level, error) {
 		return slog.LevelDebug, nil
 	case "info":
 		return slog.LevelInfo, nil
-	case "warn":
+	case "warn", "warning":
 		return slog.LevelWarn, nil
 	case "error":
 		return slog.LevelError, nil
-  default:
+	default:
 		return slog.LevelInfo, fmt.Errorf("unknown log level %s", str)
 	}
 }