Merge branch 'fix/use-git-alt-dirs-values-from-repository' into 'master'

Pass repo git alternate dirs to gitaly-ruby

Closes #682

See merge request gitlab-org/gitaly!421

6 files changed, 138 insertions, 4 deletions

diff --git a/CHANGELOG.md b/CHANGELOG.md
index 72140fca6..1476227df 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -1,5 +1,10 @@
 # Gitaly changelog
 
+UNRELEASED
+
+- Pass repo git alternate dirs to gitaly-ruby
+  https://gitlab.com/gitlab-org/gitaly/merge_requests/421
+
 v0.49.0
 
 - Use sentry fingerprinting to group exceptions
diff --git a/internal/rubyserver/proxy.go b/internal/rubyserver/proxy.go
index ee6ee137d..503d9ac8f 100644
--- a/internal/rubyserver/proxy.go
+++ b/internal/rubyserver/proxy.go
@@ -3,6 +3,8 @@ package rubyserver
 import (
 	"context"
 	"io"
+	"os"
+	"strings"
 
 	pb "gitlab.com/gitlab-org/gitaly-proto/go"
 	"gitlab.com/gitlab-org/gitaly/internal/helper"
@@ -17,7 +19,15 @@ func SetHeaders(ctx context.Context, repo *pb.Repository) (context.Context, erro
 		return nil, err
 	}
 
-	md := metadata.Pairs(repoPathHeader, repoPath, glRepositoryHeader, repo.GlRepository)
+	repoAltDirs := repo.GetGitAlternateObjectDirectories()
+	repoAltDirs = append(repoAltDirs, repo.GetGitObjectDirectory())
+	repoAltDirsCombined := strings.Join(repoAltDirs, string(os.PathListSeparator))
+
+	md := metadata.Pairs(
+		repoPathHeader, repoPath,
+		glRepositoryHeader, repo.GlRepository,
+		repoAltDirsHeader, repoAltDirsCombined,
+	)
 	newCtx := metadata.NewOutgoingContext(ctx, md)
 	return newCtx, nil
 }
diff --git a/internal/rubyserver/rubyserver.go b/internal/rubyserver/rubyserver.go
index dcbd7434c..9d0466115 100644
--- a/internal/rubyserver/rubyserver.go
+++ b/internal/rubyserver/rubyserver.go
@@ -26,6 +26,7 @@ import (
 const (
 	repoPathHeader     = "gitaly-repo-path"
 	glRepositoryHeader = "gitaly-gl-repository"
+	repoAltDirsHeader  = "gitaly-repo-alt-dirs"
 )
 
 var (
diff --git a/internal/service/commit/find_commits_test.go b/internal/service/commit/find_commits_test.go
index 788e3b1ac..0088ab928 100644
--- a/internal/service/commit/find_commits_test.go
+++ b/internal/service/commit/find_commits_test.go
@@ -2,7 +2,11 @@ package commit
 
 import (
 	"context"
+	"fmt"
 	"io"
+	"os"
+	"os/exec"
+	"path"
 	"testing"
 
 	"google.golang.org/grpc/codes"
@@ -218,6 +222,107 @@ func TestSuccessfulFindCommitsRequest(t *testing.T) {
 	}
 }
 
+func TestSuccessfulFindCommitsRequestWithAltGitObjectDirs(t *testing.T) {
+	server := startTestServices(t)
+	defer server.Stop()
+
+	client, conn := newCommitServiceClient(t, serverSocketPath)
+	defer conn.Close()
+
+	committerName := "Scrooge McDuck"
+	committerEmail := "scrooge@mcduck.com"
+
+	storagePath := testhelper.GitlabTestStoragePath()
+	testRepoPath := path.Join(storagePath, testRepo.RelativePath)
+	testRepoCopyName := "find-commits-alt-test-repo"
+	testRepoCopyPath := path.Join(storagePath, testRepoCopyName)
+	altObjectsDir := "./alt-objects"
+	altObjectsPath := path.Join(testRepoCopyPath, ".git", altObjectsDir)
+	gitObjectEnv := []string{
+		fmt.Sprintf("GIT_OBJECT_DIRECTORY=%s", altObjectsPath),
+		fmt.Sprintf("GIT_ALTERNATE_OBJECT_DIRECTORIES=%s", path.Join(testRepoCopyPath, ".git/objects")),
+	}
+
+	// This clone will store its objects in the normal location: 'find-commits-alt-test-repo/.git/objects'
+	testhelper.MustRunCommand(t, nil, "git", "clone", testRepoPath, testRepoCopyPath)
+	defer os.RemoveAll(testRepoCopyPath)
+
+	if err := os.Mkdir(altObjectsPath, 0777); err != nil {
+		t.Fatal(err)
+	}
+
+	cmd := exec.Command("git", "-C", testRepoCopyPath,
+		"-c", fmt.Sprintf("user.name=%s", committerName),
+		"-c", fmt.Sprintf("user.email=%s", committerEmail),
+		"commit", "--allow-empty", "-m", "An empty commit")
+	// Because we set 'gitObjectEnv', the new objects created by this 'git commit' command will go
+	// into 'find-commits-alt-test-repo/.git/alt-objects'.
+	cmd.Env = gitObjectEnv
+	if _, err := cmd.Output(); err != nil {
+		stderr := err.(*exec.ExitError).Stderr
+		t.Fatalf("%s", stderr)
+	}
+
+	cmd = exec.Command("git", "-C", testRepoCopyPath, "show", "--format=format:%H", "--no-patch", "HEAD")
+	cmd.Env = gitObjectEnv
+	currentHead, err := cmd.Output()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	testCases := []struct {
+		desc          string
+		altDirs       []string
+		expectedCount int
+	}{
+		{
+			desc:          "present GIT_ALTERNATE_OBJECT_DIRECTORIES",
+			altDirs:       []string{altObjectsDir},
+			expectedCount: 1,
+		},
+		{
+			desc:          "empty GIT_ALTERNATE_OBJECT_DIRECTORIES",
+			altDirs:       []string{},
+			expectedCount: 0,
+		},
+	}
+
+	for _, testCase := range testCases {
+		t.Run(testCase.desc, func(t *testing.T) {
+			request := &pb.FindCommitsRequest{
+				Repository: &pb.Repository{
+					StorageName:                   testRepo.StorageName,
+					RelativePath:                  path.Join(testRepoCopyName, ".git"),
+					GitAlternateObjectDirectories: testCase.altDirs,
+				},
+				Revision: currentHead,
+				Limit:    1,
+			}
+
+			ctx, cancel := testhelper.Context()
+			defer cancel()
+
+			c, err := client.FindCommits(ctx, request)
+			require.NoError(t, err)
+
+			receivedCommits := []*pb.GitCommit{}
+
+			for {
+				resp, err := c.Recv()
+				if err == io.EOF {
+					break
+				} else if err != nil {
+					t.Fatal(err)
+				}
+
+				receivedCommits = append(receivedCommits, resp.GetCommits()...)
+			}
+
+			require.Equal(t, testCase.expectedCount, len(receivedCommits), "number of commits received")
+		})
+	}
+}
+
 func TestFailureFindCommitsRequest(t *testing.T) {
 	server := startTestServices(t)
 	defer server.Stop()
diff --git a/ruby/lib/gitaly_server.rb b/ruby/lib/gitaly_server.rb
index 2edac0876..32e47e4c1 100644
--- a/ruby/lib/gitaly_server.rb
+++ b/ruby/lib/gitaly_server.rb
@@ -13,6 +13,7 @@ require_relative 'gitaly_server/wiki_service.rb'
 module GitalyServer
   REPO_PATH_HEADER = 'gitaly-repo-path'.freeze
   GL_REPOSITORY_HEADER = 'gitaly-gl-repository'.freeze
+  REPO_ALT_DIRS_HEADER = 'gitaly-repo-alt-dirs'.freeze
 
   def self.repo_path(call)
     call.metadata.fetch(REPO_PATH_HEADER)
@@ -22,6 +23,10 @@ module GitalyServer
     call.metadata.fetch(GL_REPOSITORY_HEADER)
   end
 
+  def self.repo_alt_dirs(call)
+    call.metadata.fetch(REPO_ALT_DIRS_HEADER)
+  end
+
   def self.register_handlers(server)
     server.handle(CommitService.new)
     server.handle(DiffService.new)
diff --git a/ruby/lib/gitlab/git.rb b/ruby/lib/gitlab/git.rb
index ba98f07d1..1c8fccf09 100644
--- a/ruby/lib/gitlab/git.rb
+++ b/ruby/lib/gitlab/git.rb
@@ -72,13 +72,21 @@ module Gitlab
   module Git
     class Repository
       def self.from_call(call)
-        new(GitalyServer.repo_path(call), GitalyServer.gl_repository(call))
+        new(
+          GitalyServer.repo_path(call),
+          GitalyServer.gl_repository(call),
+          GitalyServer.repo_alt_dirs(call)
+        )
       end
 
-      def initialize(path, gl_repository)
+      def initialize(path, gl_repository, combined_alt_dirs="")
+        alt_dirs = combined_alt_dirs
+          .split(File::PATH_SEPARATOR)
+          .map { |d| File.join(path, d) }
+
         @path = path
         @gl_repository = gl_repository
-        @rugged = Rugged::Repository.new(path)
+        @rugged = Rugged::Repository.new(path, alternates: alt_dirs)
         @attributes = Gitlab::Git::Attributes.new(path)
       end