testhelper: Don't clutter system temporary directory

During test execution, we create a lot of temporary files which we never
clean up, like for example the internal socket directory. While reigning
in on all of these "leaks" probably doesn't make a whole lot of sense,
it would still be nice to not leave behind so much garbage after test
runs. After a few hours of working, it's certainly impossible for me to
find anything of relevance in my "/tmp" directory because it's littered
with piles of Gitaly files.

Fix this by overriding the temporary directory during tests: instead of
creating them in the global temporary directory, we instead create them
in a "tmp" directory inside of our global test directory.

1 files changed, 12 insertions, 0 deletions

diff --git a/internal/testhelper/configure.go b/internal/testhelper/configure.go
index 10196f22f..ec9e49661 100644
--- a/internal/testhelper/configure.go
+++ b/internal/testhelper/configure.go
@@ -140,6 +140,18 @@ func configureTestDirectory() (_ func(), returnedErr error) {
 		return nil, err
 	}
 
+	// In many locations throughout Gitaly, we create temporary files and directories. By
+	// default, these would clutter the "real" temporary directory with useless cruft that stays
+	// around after our tests. To avoid this, we thus set the TMPDIR environment variable to
+	// point into a directory inside of out test directory.
+	globalTempDir := filepath.Join(testDirectory, "tmp")
+	if err := os.Mkdir(globalTempDir, 0o755); err != nil {
+		return nil, fmt.Errorf("creating global temporary directory: %w", err)
+	}
+	if err := os.Setenv("TMPDIR", globalTempDir); err != nil {
+		return nil, fmt.Errorf("setting global temporary directory: %w", err)
+	}
+
 	return cleanup, nil
 }