Use different Gitaly internal socket dirs in tests

In tests, we spin up two Gitaly processes along a Praefect process.
However, the Gitaly processes were sharing the same internal socket
directory to manage their gitaly-ruby subprocesses, which might cause
signals to be crossed.

Relates to https://gitlab.com/gitlab-org/gitlab/-/issues/297359

.gitlab/ci/rails.gitlab-ci.yml

@@ -162,6 +162,7 @@ setup-test-env:
       - tmp/tests/gitaly/gitaly-lfs-smudge
       - tmp/tests/gitaly/gitaly-ssh
       - tmp/tests/gitaly/internal/
+      - tmp/tests/gitaly/internal_gitaly2/
       - tmp/tests/gitaly/internal_sockets/
       - tmp/tests/gitaly/Makefile
       - tmp/tests/gitaly/praefect

lib/gitlab/setup_helper.rb

@@ -115,7 +115,7 @@ module Gitlab
 
           config[:storage] = storages
 
-          internal_socket_dir = File.join(gitaly_dir, 'internal_sockets')
+          internal_socket_dir = options[:internal_socket_dir] || File.join(gitaly_dir, 'internal_sockets')
           FileUtils.mkdir(internal_socket_dir) unless File.exist?(internal_socket_dir)
           config[:internal_socket_dir] = internal_socket_dir
 

spec/support/helpers/test_env.rb

@@ -172,8 +172,13 @@ module TestEnv
         Gitlab::SetupHelper::Gitaly.create_configuration(gitaly_dir, { 'default' => repos_path }, force: true)
         Gitlab::SetupHelper::Gitaly.create_configuration(
           gitaly_dir,
-          { 'default' => repos_path }, force: true,
-          options: { gitaly_socket: "gitaly2.socket", config_filename: "gitaly2.config.toml" }
+          { 'default' => repos_path },
+          force: true,
+          options: {
+            internal_socket_dir: File.join(gitaly_dir, "internal_gitaly2"),
+            gitaly_socket: "gitaly2.socket",
+            config_filename: "gitaly2.config.toml"
+          }
         )
         Gitlab::SetupHelper::Praefect.create_configuration(gitaly_dir, { 'praefect' => repos_path }, force: true)
       end