go-vise

commit 2befd169e9fcbb1f84d94ebd711f85be964a717c
parent fd3db37d26269c3b57eaa192bcaa11c7fbb156f6
Author: lash <dev@holbrook.no>
Date:   Fri,  3 Jan 2025 08:49:47 +0000

Add custom context key in slogging

Signed-off-by: lash <dev@holbrook.no>

Diffstat:
M
logging/vanilla.go
 | 
23
+++++++++++++++++++----
M
logging/vanilla_test.go
 | 
18
++++++++++++++++++

2 files changed, 37 insertions(+), 4 deletions(-)
diff --git a/logging/vanilla.go b/logging/vanilla.go
@@ -11,13 +11,14 @@ import (
 
 var (
 	// LogWriter is used as io.Writer the Vanilla Logger implementation.
-	LogWriter = os.Stderr
+	LogWriter io.Writer = os.Stderr
 )
 
 // Vanilla is a basic single-line structured output logger for terminal output.
 type Vanilla struct {
 	domain      string
 	levelFilter int
+	ctxkey	[]string
 }
 
 // NewVanilla creates a new Vanilla logger.
@@ -40,6 +41,11 @@ func (v Vanilla) WithLevel(level int) Vanilla {
 	return v
 }
 
+func (v Vanilla) WithContextKey(k string) Vanilla {
+	v.ctxkey = append(v.ctxkey, k)
+	return v
+}
+
 // Printf logs to the global writer.
 func (v Vanilla) Printf(level int, msg string, args ...any) {
 	v.Writef(LogWriter, level, msg, args...)
@@ -52,9 +58,9 @@ func (v Vanilla) writef(ctx context.Context, w io.Writer, file string, line int,
 		return
 	}
 	if ctx == nil {
-		argsStr = argsToString(nil, args)
+		argsStr = v.argsToString(nil, args)
 	} else {
-		argsStr = argsToString(ctx, args)
+		argsStr = v.argsToString(ctx, args)
 	}
 
 	if len(msg) > 0 {
@@ -153,7 +159,7 @@ func getCaller(depth int) (string, int) {
 }
 
 // string representation of the given structured log args.
-func argsToString(ctx context.Context, args []any) string {
+func (v Vanilla) argsToString(ctx context.Context, args []any) string {
 	var s string
 
 	if ctx != nil {
@@ -162,6 +168,15 @@ func argsToString(ctx context.Context, args []any) string {
 			args = append(args, "session-id", sessionId)
 		}
 	}
+	for _, k := range(v.ctxkey) {
+		v := ctx.Value(k)
+		if v != nil {
+			v, ok := v.(string)
+			if ok {
+				args = append(args, "x-" + k, v)
+			}
+		}
+	}
 	c := len(args)
 	var i int
 	for i = 0; i < c; i += 2 {
diff --git a/logging/vanilla_test.go b/logging/vanilla_test.go
@@ -2,6 +2,8 @@ package logging
 
 import (
 	"bytes"
+	"context"
+	"strings"
 	"testing"
 )
 
@@ -18,3 +20,19 @@ func TestVanilla(t *testing.T) {
 		t.Errorf("expected output")
 	}
 }
+
+func TestVanillaCtx(t *testing.T) {
+	logg := NewVanilla().WithDomain("test").WithLevel(LVL_DEBUG).WithContextKey("foo")
+	ctx := context.WithValue(context.Background(), "foo", "bar") 
+	w := bytes.NewBuffer(nil)
+	LogWriter = w
+
+	logg.DebugCtxf(ctx, "message", "xyzzy", 666, "inky", "pinky")
+	s := string(w.Bytes())
+	if len(s) == 0 {
+		t.Errorf("expected output")
+	}
+	if !strings.Contains(s, "foo=bar") {
+		t.Errorf("expected 'foo=bar' in output, output was: %s", s)
+	}
+}