Configure opentelemetry-go's logger

This adds a little adapter from zap to opentelemetry-go's expected
logger interface, so we can get opentelemetry logs.

Author: nickstenning

go.mod

@@ -4,6 +4,7 @@ go 1.22
 
 require (
 	github.com/getsentry/sentry-go v0.27.0
+	github.com/go-logr/logr v1.4.1
 	github.com/go-redis/redismock/v9 v9.2.0
 	github.com/golangci/golangci-lint v1.57.2
 	github.com/hashicorp/go-retryablehttp v0.7.5
@@ -79,7 +80,6 @@ require (
 	github.com/fzipp/gocyclo v0.6.0 // indirect
 	github.com/ghostiam/protogetter v0.3.5 // indirect
 	github.com/go-critic/go-critic v0.11.2 // indirect
-	github.com/go-logr/logr v1.4.1 // indirect
 	github.com/go-logr/stdr v1.2.2 // indirect
 	github.com/go-toolsmith/astcast v1.1.0 // indirect
 	github.com/go-toolsmith/astcopy v1.1.0 // indirect

telemetry/logger.go

@@ -0,0 +1,59 @@
+package telemetry
+
+import (
+	"github.com/go-logr/logr"
+	"go.uber.org/zap"
+	"go.uber.org/zap/zapcore"
+)
+
+type zapAdapter struct {
+	logger *zap.Logger
+}
+
+func (z *zapAdapter) Init(info logr.RuntimeInfo) {
+	// +1 for this wrapper
+	// +1 for opentelemetry-go's internal_logging.go
+	skip := info.CallDepth + 2
+	z.logger = z.logger.WithOptions(zap.AddCallerSkip(skip))
+}
+
+func (z *zapAdapter) Enabled(level int) bool {
+	return z.logger.Core().Enabled(mapLevel(level))
+}
+
+func (z *zapAdapter) Info(level int, msg string, keysAndValues ...any) {
+	z.logger.Sugar().Logw(mapLevel(level), msg, keysAndValues...)
+}
+
+func (z *zapAdapter) Error(err error, msg string, keysAndValues ...any) {
+	keysAndValues = append(keysAndValues, "error", err)
+	z.logger.Sugar().Errorw(msg, keysAndValues...)
+}
+
+func (z *zapAdapter) WithValues(keysAndValues ...any) logr.LogSink {
+	return &zapAdapter{
+		logger: z.logger.Sugar().With(keysAndValues...).Desugar(),
+	}
+}
+
+func (z *zapAdapter) WithName(name string) logr.LogSink {
+	return &zapAdapter{
+		logger: z.logger.Named(name),
+	}
+}
+
+// mapLevel maps the levels used by opentelemetry-go to zap levels.
+//
+// See:
+//
+//	https://github.com/open-telemetry/opentelemetry-go/blob/1297d5f0/internal/global/internal_logging.go#L30-L32
+func mapLevel(level int) zapcore.Level {
+	switch {
+	case level <= 1:
+		return zapcore.WarnLevel
+	case level <= 4:
+		return zapcore.InfoLevel
+	default:
+		return zapcore.DebugLevel
+	}
+}

telemetry/telemetry.go

@@ -16,6 +16,7 @@ import (
 	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
 	"go.opentelemetry.io/otel/trace"
 
+	"github.com/go-logr/logr"
 	"github.com/replicate/go/logging"
 	"github.com/replicate/go/version"
 )
@@ -34,6 +35,7 @@ func Start(ctx context.Context) (*Telemetry, error) {
 		return nil, err
 	}
 
+	otel.SetLogger(logr.New(&zapAdapter{logger: logger}))
 	otel.SetErrorHandler(ErrorHandler{})
 	otel.SetTracerProvider(tp)
 	otel.SetTextMapPropagator(