gitaly: Move Gitaly-specific code into `internal/gitaly`

Since the introduction of Praefect, our code layout started to become
confusing: while Praefect code lives in `internal/praefect`,
Gitaly-specific code is all over the place and not neatly singled out.
This makes it hard at times to tell apart Praefect- and Gitaly-specific
from generic code.

To improve the situation, this commit thus moves most of the server
specific code into a new `internal/gitaly` package. Currently, this is
the `internal/config`, `internal/server`, `internal/service` and
`internal/rubyserver` packages, which are all main components of Gitaly.
The move was realized with the following script:

    #!/bin/sh
    mkdir -p internal/gitaly
    git mv internal/{config,server,service,rubyserver} internal/gitaly/
    find . -name '*.go' -exec sed -i \
        -e 's|gitlab-org/gitaly/internal/rubyserver|gitlab-org/gitaly/internal/gitaly/rubyserver|' \
        -e 's|gitlab-org/gitaly/internal/server|gitlab-org/gitaly/internal/gitaly/server|' \
        -e 's|gitlab-org/gitaly/internal/service|gitlab-org/gitaly/internal/gitaly/service|' \
        -e 's|gitlab-org/gitaly/internal/config|gitlab-org/gitaly/internal/gitaly/config|' {} \;

In addition to that, some minor adjustments were needed for tests which
used relative paths.

1 files changed, 134 insertions, 0 deletions

diff --git a/internal/gitaly/service/operations/merge.go b/internal/gitaly/service/operations/merge.go
new file mode 100644
index 000000000..4cdc43d5d
--- /dev/null
+++ b/internal/gitaly/service/operations/merge.go
@@ -0,0 +1,134 @@
+package operations
+
+import (
+	"context"
+	"fmt"
+	"strings"
+
+	"gitlab.com/gitlab-org/gitaly/internal/gitaly/rubyserver"
+	"gitlab.com/gitlab-org/gitaly/internal/helper"
+	"gitlab.com/gitlab-org/gitaly/proto/go/gitalypb"
+)
+
+func (s *server) UserMergeBranch(bidi gitalypb.OperationService_UserMergeBranchServer) error {
+	firstRequest, err := bidi.Recv()
+	if err != nil {
+		return err
+	}
+
+	ctx := bidi.Context()
+	client, err := s.ruby.OperationServiceClient(ctx)
+	if err != nil {
+		return err
+	}
+
+	clientCtx, err := rubyserver.SetHeaders(ctx, firstRequest.GetRepository())
+	if err != nil {
+		return err
+	}
+
+	rubyBidi, err := client.UserMergeBranch(clientCtx)
+	if err != nil {
+		return err
+	}
+
+	if err := rubyBidi.Send(firstRequest); err != nil {
+		return err
+	}
+
+	return rubyserver.ProxyBidi(
+		func() error {
+			request, err := bidi.Recv()
+			if err != nil {
+				return err
+			}
+
+			return rubyBidi.Send(request)
+		},
+		rubyBidi,
+		func() error {
+			response, err := rubyBidi.Recv()
+			if err != nil {
+				return err
+			}
+
+			return bidi.Send(response)
+		},
+	)
+}
+
+func validateFFRequest(in *gitalypb.UserFFBranchRequest) error {
+	if len(in.Branch) == 0 {
+		return fmt.Errorf("empty branch name")
+	}
+
+	if in.User == nil {
+		return fmt.Errorf("empty user")
+	}
+
+	if in.CommitId == "" {
+		return fmt.Errorf("empty commit id")
+	}
+
+	return nil
+}
+
+func (s *server) UserFFBranch(ctx context.Context, in *gitalypb.UserFFBranchRequest) (*gitalypb.UserFFBranchResponse, error) {
+	if err := validateFFRequest(in); err != nil {
+		return nil, helper.ErrInvalidArgument(err)
+	}
+
+	client, err := s.ruby.OperationServiceClient(ctx)
+	if err != nil {
+		return nil, err
+	}
+
+	clientCtx, err := rubyserver.SetHeaders(ctx, in.GetRepository())
+	if err != nil {
+		return nil, err
+	}
+
+	return client.UserFFBranch(clientCtx, in)
+}
+
+func validateUserMergeToRefRequest(in *gitalypb.UserMergeToRefRequest) error {
+	if len(in.FirstParentRef) == 0 && len(in.Branch) == 0 {
+		return fmt.Errorf("empty first parent ref and branch name")
+	}
+
+	if in.User == nil {
+		return fmt.Errorf("empty user")
+	}
+
+	if in.SourceSha == "" {
+		return fmt.Errorf("empty source SHA")
+	}
+
+	if len(in.TargetRef) == 0 {
+		return fmt.Errorf("empty target ref")
+	}
+
+	if !strings.HasPrefix(string(in.TargetRef), "refs/merge-requests") {
+		return fmt.Errorf("invalid target ref")
+	}
+
+	return nil
+}
+
+func (s *server) UserMergeToRef(ctx context.Context, in *gitalypb.UserMergeToRefRequest) (*gitalypb.UserMergeToRefResponse, error) {
+	if err := validateUserMergeToRefRequest(in); err != nil {
+		return nil, helper.ErrInvalidArgument(err)
+	}
+
+	client, err := s.ruby.OperationServiceClient(ctx)
+	if err != nil {
+		return nil, helper.ErrInternal(err)
+	}
+
+	clientCtx, err := rubyserver.SetHeaders(ctx, in.GetRepository())
+	if err != nil {
+		return nil, err
+	}
+
+	return client.UserMergeToRef(clientCtx, in)
+}