Reduce the amount of info being sent to Sentry

lib/setup/setup.go

@@ -4,12 +4,13 @@
 package setup
 
 import (
+	"fmt"
 	"log"
 	"log/slog"
 	"os"
+	"context"
 	"runtime/debug"
 	"strings"
-	"fmt"
 	"time"
 
 	"github.com/getsentry/sentry-go"
@@ -24,6 +25,43 @@ const (
 	EnvSentryDsn = "SPN_SENTRY_DSN"
 )
 
+type Multihandler struct {
+	sentry, json slog.Handler
+}
+
+func (h Multihandler) Enabled(ctx context.Context, record slog.Level) bool {
+	// The JSON handler should be the furthest we're going.
+	return h.sentry.Enabled(ctx, record)
+}
+func (h Multihandler) WithAttrs(attrs []slog.Attr) slog.Handler {
+	var s slog.Handler
+	if h.sentry != nil {
+		s = h.sentry.WithAttrs(attrs)
+	}
+	return Multihandler{
+		sentry: s,
+		json: h.json.WithAttrs(attrs),
+	}
+}
+func (h Multihandler) WithGroup(name string) slog.Handler {
+	var s slog.Handler
+	if h.sentry != nil {
+		s = h.sentry.WithGroup(name)
+	}
+	return Multihandler{
+		sentry: s,
+		json: h.json.WithGroup(name),
+	}
+}
+func (h Multihandler) Handle(ctx context.Context, record slog.Record) error {
+	if s := h.sentry; s != nil {
+		if err := s.Handle(ctx, record); err != nil {
+			return err
+		}
+	}
+	return h.json.Handle(ctx, record)
+}
+
 func init() {
 	// Set up the logging to print JSON blobs.
 	logLevel := slog.LevelInfo
@@ -41,15 +79,18 @@ func init() {
 			panic(fmt.Sprintf("failed to set up sentry: %v", err))
 		}
 	}
-	var logger *slog.Logger
+	var multihandler Multihandler
 	if dsn != "" { // DSN being set means we're using Sentry.
-		slogSentryOpts := slogsentry.Option{Level: logLevel}.NewSentryHandler()
-		logger = slog.New(slogSentryOpts)
-	} else {
-		logger = slog.New(slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
-			Level: logLevel,
-		}))
+		// We want to only track errors with Sentry.
+		multihandler.sentry = slogsentry.Option{
+			Level: slog.LevelError,
+		}.
+			NewSentryHandler()
 	}
+	multihandler.json = slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{
+		Level: logLevel,
+	})
+	logger := slog.New(multihandler)
 	// Find the commit hash (taken straight from
 	// https:icinga.com/blog/2022/05/25/embedding-git-commit-information-in-go-binaries/)
 	var revision string