feat: load attributes from context

samber · Apr 26, 2024 · 86ca344 · 86ca344
1 parent 105b484
commit 86ca344
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Showing 4 changed files with 48 additions and 4 deletions.
diff --git a/README.md b/README.md
@@ -79,6 +79,8 @@ type Option struct {
 
 	// optional: customize json payload builder
 	Converter Converter
+    // optional: fetch attributes from context
+    AttrFromContext []func(ctx context.Context) []slog.Attr
 
 	// optional: see slog.HandlerOptions
 	AddSource   bool
@@ -131,6 +133,41 @@ func main() {
 }
 ```
 
+### Tracing
+
+Import the samber/slog-otel library.
+
+```go
+import (
+	slogzap "github.com/samber/slog-zap"
+	slogotel "github.com/samber/slog-otel"
+	"go.opentelemetry.io/otel/sdk/trace"
+)
+
+func main() {
+	tp := trace.NewTracerProvider(
+		trace.WithSampler(trace.AlwaysSample()),
+	)
+	tracer := tp.Tracer("hello/world")
+
+	ctx, span := tracer.Start(context.Background(), "foo")
+	defer span.End()
+
+	span.AddEvent("bar")
+
+	logger := slog.New(
+		slogzap.Option{
+			// ...
+			AttrFromContext: []func(ctx context.Context) []slog.Attr{
+				slogotel.ExtractOtelAttrFromContext([]string{"tracing"}, "trace_id", "span_id"),
+			},
+		}.NewZapHandler(),
+	)
+
+	logger.ErrorContext(ctx, "a message")
+}
+```
+
 ## 🤝 Contributing
 
 - Ping me on twitter [@samuelberthe](https://twitter.com/samuelberthe) (DMs, mentions, whatever :))

diff --git a/go.mod b/go.mod
@@ -3,7 +3,7 @@ module github.com/samber/slog-zap/v2
 go 1.21
 
 require (
-	github.com/samber/slog-common v0.15.2
+	github.com/samber/slog-common v0.16.0
 	go.uber.org/goleak v1.2.1
 	go.uber.org/zap v1.26.0
 )

diff --git a/go.sum b/go.sum
@@ -4,8 +4,8 @@ github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZb
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/samber/lo v1.38.1 h1:j2XEAqXKb09Am4ebOg31SpvzUTTs6EN3VfgeLUhPdXM=
 github.com/samber/lo v1.38.1/go.mod h1:+m/ZKRl6ClXCE2Lgf3MsQlWfh4bn1bz6CXEOxnEXnEA=
-github.com/samber/slog-common v0.15.2 h1:jQQK2MzJ1kfEsUyxI/mpwkqB2xI0qCo9Ne1D1yziuP0=
-github.com/samber/slog-common v0.15.2/go.mod h1:Qjrfhwk79XiCIhBj8+jTq1Cr0u9rlWbjawh3dWXzaHk=
+github.com/samber/slog-common v0.16.0 h1:2/t1EcFd1Ru77mh2ab+8B6NBHnEXsBBHtOJc7PSH0aI=
+github.com/samber/slog-common v0.16.0/go.mod h1:Qjrfhwk79XiCIhBj8+jTq1Cr0u9rlWbjawh3dWXzaHk=
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
 go.uber.org/goleak v1.2.1 h1:NBol2c7O1ZokfZ0LEU9K6Whx/KnwvepVetCUhtKja4A=

diff --git a/handler.go b/handler.go
@@ -17,6 +17,8 @@ type Option struct {
 
 	// optional: zap logger (default: zap.L())
 	Logger *zap.Logger
+	// optional: fetch attributes from context
+	AttrFromContext []func(ctx context.Context) []slog.Attr
 
 	// optional: customize json payload builder
 	Converter Converter
@@ -36,6 +38,10 @@ func (o Option) NewZapHandler() slog.Handler {
 		o.Logger = zap.L()
 	}
 
+	if o.AttrFromContext == nil {
+		o.AttrFromContext = []func(ctx context.Context) []slog.Attr{}
+	}
+
 	return &ZapHandler{
 		option: o,
 		attrs:  []slog.Attr{},
@@ -62,7 +68,8 @@ func (h *ZapHandler) Handle(ctx context.Context, record slog.Record) error {
 	}
 
 	level := LogLevels[record.Level]
-	fields := converter(h.option.AddSource, h.option.ReplaceAttr, h.attrs, h.groups, &record)
+	fromContext := slogcommon.ContextExtractor(ctx, h.option.AttrFromContext)
+	fields := converter(h.option.AddSource, h.option.ReplaceAttr, append(h.attrs, fromContext...), h.groups, &record)
 
 	checked := h.option.Logger.Check(level, record.Message)
 	if checked != nil {