more work getting it working in Go

Signed-off-by: Xe Iaso <me@xeiaso.net>

1 files changed, 58 insertions, 0 deletions

diff --git a/internal/slog.go b/internal/slog.go
new file mode 100644
index 0000000..f54e19e
--- /dev/null
+++ b/internal/slog.go
@@ -0,0 +1,58 @@
+package internal
+
+import (
+	"flag"
+	"fmt"
+	"io"
+	"log/slog"
+	"net/http"
+	"os"
+)
+
+var (
+	slogLevel = flag.String("slog-level", "INFO", "log level")
+
+	leveler *slog.LevelVar
+)
+
+func Slog() {
+	var programLevel slog.Level
+	if err := (&programLevel).UnmarshalText([]byte(*slogLevel)); err != nil {
+		fmt.Fprintf(os.Stderr, "invalid log level %s: %v, using info\n", *slogLevel, err)
+		programLevel = slog.LevelInfo
+	}
+
+	leveler = &slog.LevelVar{}
+	leveler.Set(programLevel)
+
+	h := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
+		AddSource: true,
+		Level:     leveler,
+	})
+	slog.SetDefault(slog.New(h))
+
+	http.HandleFunc("/.within/debug/slog-level", func(w http.ResponseWriter, r *http.Request) {
+		var level, old slog.Level
+		old = leveler.Level()
+
+		if r.Method == http.MethodPost {
+			data, err := io.ReadAll(http.MaxBytesReader(w, r.Body, 64))
+			defer r.Body.Close()
+			if err != nil {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+
+			if err := (&level).UnmarshalText(data); err != nil {
+				http.Error(w, err.Error(), http.StatusBadRequest)
+				return
+			}
+
+			leveler.Set(level)
+			slog.Info("changed level", "from", old, "to", level)
+			fmt.Fprintln(w, level)
+		} else {
+			fmt.Fprintln(w, old)
+		}
+	})
+}