git: Add gitalyPid option to NewExecCommandFactoryjc-spawn-git-in-pgid

We want all git commands to be tied to a pgid, the gitaly process. This
way, when gitaly gets killed, all git processes can be killed alongside it,
in case there are any zombie processes hanging around.

Add a gitalyPid option to the NewExecCommandFactory() constructor, and
update the callsites with the option.

Changelog: changed

2 files changed, 17 insertions, 1 deletions

diff --git a/cmd/gitaly/main.go b/cmd/gitaly/main.go
index e1097b866..24bc65a0a 100644
--- a/cmd/gitaly/main.go
+++ b/cmd/gitaly/main.go
@@ -196,7 +196,10 @@ func run(cfg config.Cfg) error {
 	}
 
 	skipHooks, _ := env.GetBool("GITALY_TESTING_NO_GIT_HOOKS", false)
-	var commandFactoryOpts []git.ExecCommandFactoryOption
+	commandFactoryOpts := []git.ExecCommandFactoryOption{
+		git.WithGitalyPid(os.Getpid()),
+	}
+
 	if skipHooks {
 		commandFactoryOpts = append(commandFactoryOpts, git.WithSkipHooks())
 	}
diff --git a/internal/git/command_factory.go b/internal/git/command_factory.go
index dae719935..53444b43b 100644
--- a/internal/git/command_factory.go
+++ b/internal/git/command_factory.go
@@ -43,6 +43,7 @@ type CommandFactory interface {
 type execCommandFactoryConfig struct {
 	hooksPath     string
 	gitBinaryPath string
+	gitalyPid     int
 }
 
 // ExecCommandFactoryOption is an option that can be passed to NewExecCommandFactory.
@@ -69,6 +70,14 @@ func WithGitBinaryPath(path string) ExecCommandFactoryOption {
 	}
 }
 
+// WithGitalyPid will cause new commands to be started under the gitaly pid as
+// the pgid
+func WithGitalyPid(gitalyPid int) ExecCommandFactoryOption {
+	return func(cfg *execCommandFactoryConfig) {
+		cfg.gitalyPid = gitalyPid
+	}
+}
+
 type hookDirectories struct {
 	tempHooksPath string
 }
@@ -89,6 +98,8 @@ type ExecCommandFactory struct {
 
 	cachedGitVersionLock     sync.RWMutex
 	cachedGitVersionByBinary map[string]cachedGitVersion
+
+	gitalyPid int
 }
 
 // NewExecCommandFactory returns a new instance of initialized ExecCommandFactory. The returned
@@ -138,6 +149,7 @@ func NewExecCommandFactory(cfg config.Cfg, opts ...ExecCommandFactoryOption) (_
 		),
 		hookDirs:                 hookDirectories,
 		cachedGitVersionByBinary: make(map[string]cachedGitVersion),
+		gitalyPid:                factoryCfg.gitalyPid,
 	}
 
 	return gitCmdFactory, runCleanups, nil
@@ -413,6 +425,7 @@ func (cf *ExecCommandFactory) newCommand(ctx context.Context, repo repository.Gi
 		command.WithCommandName("git", sc.Subcommand()),
 		command.WithCgroup(cf.cgroupsManager, repo),
 		command.WithCommandGitVersion(cmdGitVersion.String()),
+		command.WithParent(cf.gitalyPid),
 	)...)
 	if err != nil {
 		return nil, err