Cleanup for the feature flag protection of the GetTagMessages method

Feature flag removed.
Clean up of go code that triggers Gitaly-Ruby code.
Removal of related Prometheus metrics

Part of: https://gitlab.com/gitlab-org/gitaly/issues/2208

3 files changed, 4 insertions, 81 deletions

diff --git a/internal/metadata/featureflag/feature_flags.go b/internal/metadata/featureflag/feature_flags.go
index 3a4a33031..d64c00909 100644
--- a/internal/metadata/featureflag/feature_flags.go
+++ b/internal/metadata/featureflag/feature_flags.go
@@ -4,8 +4,6 @@ const (
 	// UploadPackFilter enables partial clones by sending uploadpack.allowFilter and uploadpack.allowAnySHA1InWant
 	// to upload-pack
 	UploadPackFilter = "upload_pack_filter"
-	// GetTagMessagesGo will cause the GetTagMessages RPC to use the go implementation when set
-	GetTagMessagesGo = "get_tag_messages_go"
 	// FilterShasWithSignaturesGo will cause the FilterShasWithSignatures RPC to use the go implementation when set
 	FilterShasWithSignaturesGo = "filter_shas_with_signatures_go"
 	// LinguistFileCountStats will invoke an additional git-linguist command to get the number of files per language
diff --git a/internal/service/ref/tag_messages.go b/internal/service/ref/tag_messages.go
index 88bf9b27d..e632dd7f8 100644
--- a/internal/service/ref/tag_messages.go
+++ b/internal/service/ref/tag_messages.go
@@ -5,30 +5,15 @@ import (
 	"fmt"
 	"io"
 
-	"github.com/prometheus/client_golang/prometheus"
 	"gitlab.com/gitlab-org/gitaly/internal/git/catfile"
 	"gitlab.com/gitlab-org/gitaly/internal/git/log"
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
-	"gitlab.com/gitlab-org/gitaly/internal/metadata/featureflag"
-	"gitlab.com/gitlab-org/gitaly/internal/rubyserver"
 	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
 	"gitlab.com/gitlab-org/gitaly/streamio"
 	"google.golang.org/grpc/codes"
 	"google.golang.org/grpc/status"
 )
 
-var getTagMessagesRequests = prometheus.NewCounterVec(
-	prometheus.CounterOpts{
-		Name: "gitaly_get_tag_messages_total",
-		Help: "Counter of go vs ruby implementation of GetTagMessages",
-	},
-	[]string{"implementation"},
-)
-
-func init() {
-	prometheus.MustRegister(getTagMessagesRequests)
-}
-
 func (s *server) GetTagMessages(request *gitalypb.GetTagMessagesRequest, stream gitalypb.RefService_GetTagMessagesServer) error {
 	if err := validateGetTagMessagesRequest(request); err != nil {
 		return status.Errorf(codes.InvalidArgument, "GetTagMessages: %v", err)
@@ -49,16 +34,6 @@ func validateGetTagMessagesRequest(request *gitalypb.GetTagMessagesRequest) erro
 }
 
 func (s *server) getAndStreamTagMessages(request *gitalypb.GetTagMessagesRequest, stream gitalypb.RefService_GetTagMessagesServer) error {
-	if featureflag.IsEnabled(stream.Context(), featureflag.GetTagMessagesGo) {
-		getTagMessagesRequests.WithLabelValues("go").Inc()
-		return getAndStreamTagMessagesGo(request, stream)
-	}
-
-	getTagMessagesRequests.WithLabelValues("ruby").Inc()
-	return getAndStreamTagMessagesRuby(s.ruby, request, stream)
-}
-
-func getAndStreamTagMessagesGo(request *gitalypb.GetTagMessagesRequest, stream gitalypb.RefService_GetTagMessagesServer) error {
 	ctx := stream.Context()
 
 	c, err := catfile.New(ctx, request.GetRepository())
@@ -87,32 +62,3 @@ func getAndStreamTagMessagesGo(request *gitalypb.GetTagMessagesRequest, stream g
 	}
 	return nil
 }
-
-func getAndStreamTagMessagesRuby(ruby *rubyserver.Server, request *gitalypb.GetTagMessagesRequest, stream gitalypb.RefService_GetTagMessagesServer) error {
-	ctx := stream.Context()
-
-	client, err := ruby.RefServiceClient(ctx)
-	if err != nil {
-		return err
-	}
-
-	clientCtx, err := rubyserver.SetHeaders(ctx, request.GetRepository())
-	if err != nil {
-		return err
-	}
-
-	rubyStream, err := client.GetTagMessages(clientCtx, request)
-	if err != nil {
-		return err
-	}
-
-	return rubyserver.Proxy(func() error {
-		resp, err := rubyStream.Recv()
-		if err != nil {
-			md := rubyStream.Trailer()
-			stream.SetTrailer(md)
-			return err
-		}
-		return stream.Send(resp)
-	})
-}
diff --git a/internal/service/ref/tag_messages_test.go b/internal/service/ref/tag_messages_test.go
index d5b38af1f..fbd8ebac0 100644
--- a/internal/service/ref/tag_messages_test.go
+++ b/internal/service/ref/tag_messages_test.go
@@ -1,18 +1,15 @@
 package ref
 
 import (
-	"context"
 	"io"
 	"strings"
 	"testing"
 
 	"github.com/stretchr/testify/require"
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
-	"gitlab.com/gitlab-org/gitaly/internal/metadata/featureflag"
 	"gitlab.com/gitlab-org/gitaly/internal/testhelper"
 	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
 	"google.golang.org/grpc/codes"
-	"google.golang.org/grpc/metadata"
 )
 
 func TestSuccessfulGetTagMessagesRequest(t *testing.T) {
@@ -50,23 +47,11 @@ func TestSuccessfulGetTagMessagesRequest(t *testing.T) {
 		},
 	}
 
-	for title, ctxModifier := range map[string]func(context.Context) context.Context{
-		"enabled_feature_GetTagMessagesGo": func(ctx context.Context) context.Context {
-			return enableGetTagMessagesFeatureFlag(ctx)
-		},
-		"disabled_feature_GetTagMessagesGo": func(ctx context.Context) context.Context {
-			return ctx
-		},
-	} {
-		t.Run(title, func(t *testing.T) {
-			c, err := client.GetTagMessages(ctxModifier(ctx), request)
-			require.NoError(t, err)
-
-			fetchedMessages := readAllMessagesFromClient(t, c)
+	c, err := client.GetTagMessages(ctx, request)
+	require.NoError(t, err)
 
-			require.Equal(t, expectedMessages, fetchedMessages)
-		})
-	}
+	fetchedMessages := readAllMessagesFromClient(t, c)
+	require.Equal(t, expectedMessages, fetchedMessages)
 }
 
 func TestFailedGetTagMessagesRequest(t *testing.T) {
@@ -131,9 +116,3 @@ func readAllMessagesFromClient(t *testing.T, c gitalypb.RefService_GetTagMessage
 
 	return
 }
-
-func enableGetTagMessagesFeatureFlag(ctx context.Context) context.Context {
-	return metadata.NewOutgoingContext(ctx, metadata.New(map[string]string{
-		featureflag.HeaderKey(featureflag.GetTagMessagesGo): "true",
-	}))
-}