requestinfohandler: Restore missing log fields in SSHReceivePack

a497cfc8 replaced the v1 grpc-go-middleware `Tags` with the v2
`logging.Fields`, but this caused fields such as `correlation_id` and
`user_id` to be dropped for calls such as `SSHReceivePack`. This
occurred because the logger still uses the v1
`StreamServerInterceptor` and `UnaryServerInterceptor`, which extracts
logging fields from a different context key than the one used by v2
interceptors.

To restore these logging fields until the v2 middlewares are used,
restore the v1 `Tags`. This means we have a bit of redundancy since
the fields are stored for both v1 and v2 formats. However, once
https://gitlab.com/gitlab-org/gitaly/-/work_items/5661 is complete,
the v1 middleware and `Tags` can be dropped.

Changelog: fixed

2 files changed, 23 insertions, 0 deletions

diff --git a/internal/grpc/middleware/requestinfohandler/requestinfohandler.go b/internal/grpc/middleware/requestinfohandler/requestinfohandler.go
index 01ca81929..0d738c98e 100644
--- a/internal/grpc/middleware/requestinfohandler/requestinfohandler.go
+++ b/internal/grpc/middleware/requestinfohandler/requestinfohandler.go
@@ -4,6 +4,7 @@ import (
 	"context"
 	"strings"
 
+	grpcmwtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/logging"
 	grpcprometheus "github.com/grpc-ecosystem/go-grpc-prometheus"
 	"github.com/prometheus/client_golang/prometheus"
@@ -196,9 +197,18 @@ func (i *RequestInfo) extractRequestInfo(request any) {
 }
 
 func (i *RequestInfo) injectTags(ctx context.Context) context.Context {
+	tags := grpcmwtags.NewTags()
+
 	for key, value := range i.Tags() {
 		ctx = logging.InjectLogField(ctx, key, value)
+		tags.Set(key, value)
 	}
+
+	// This maintains backward compatibility for tags in the v1 grpc-go-middleware.
+	// This can be removed when the v1 interceptors are removed:
+	// https://gitlab.com/gitlab-org/gitaly/-/work_items/5661
+	ctx = grpcmwtags.SetInContext(ctx, tags)
+
 	return ctx
 }
 
diff --git a/internal/grpc/middleware/requestinfohandler/requestinfohandler_test.go b/internal/grpc/middleware/requestinfohandler/requestinfohandler_test.go
index 5e62707cd..38e40faeb 100644
--- a/internal/grpc/middleware/requestinfohandler/requestinfohandler_test.go
+++ b/internal/grpc/middleware/requestinfohandler/requestinfohandler_test.go
@@ -7,6 +7,7 @@ import (
 	"testing"
 	"time"
 
+	grpcmwtags "github.com/grpc-ecosystem/go-grpc-middleware/tags"
 	"github.com/grpc-ecosystem/go-grpc-middleware/v2/interceptors/logging"
 	"github.com/stretchr/testify/require"
 	gitalylog "gitlab.com/gitlab-org/gitaly/v16/internal/log"
@@ -283,6 +284,18 @@ func TestGRPCTags(t *testing.T) {
 			"grpc.request.fullMethod":    "/gitaly.RepositoryService/OptimizeRepository",
 		}, gitalylog.ConvertLoggingFields(fields))
 
+		legacyFields := grpcmwtags.Extract(ctx).Values()
+
+		require.Equal(t, map[string]any{
+			"correlation_id":             correlationID,
+			"grpc.meta.client_name":      clientName,
+			"grpc.meta.deadline_type":    "none",
+			"grpc.meta.method_type":      "unary",
+			"grpc.meta.method_operation": "maintenance",
+			"grpc.meta.method_scope":     "repository",
+			"grpc.request.fullMethod":    "/gitaly.RepositoryService/OptimizeRepository",
+		}, legacyFields)
+
 		return nil, nil
 	})
 	require.NoError(t, err)