controllers: control tar ignores w/ exclude files

This commit changes the file excludes for tarballs generated for
Git repository artifacts from a fixed set of strings to include
exclusion files files. It currently takes `.sourceignore` and
in the root of the given directory into account.

In addition to this the Git VCS related files that are ignored have
been extended to not only include the .git/ directory, but also the
.gitignore, .gitmodules and .gitattributes files.
In addition to this, it adds the `--exclude-vcs` option to the tar
command so that all VCS related files are always excluded.

controllers/gitrepository_controller.go

@@ -345,7 +345,7 @@ func (r *GitRepositoryReconciler) sync(ctx context.Context, repository sourcev1.
 	defer unlock()
 
 	// archive artifact and check integrity
-	err = r.Storage.Archive(artifact, tmpGit, "", true)
+	err = r.Storage.Archive(artifact, tmpGit, true)
 	if err != nil {
 		err = fmt.Errorf("storage archive error: %w", err)
 		return sourcev1.GitRepositoryNotReady(repository, sourcev1.StorageOperationFailedReason, err.Error()), err

controllers/storage.go

@@ -33,6 +33,12 @@ import (
 	"github.com/fluxcd/source-controller/internal/lockedfile"
 )
 
+const (
+	excludeFile     = ".sourceignore"
+	excludeVCS      = ".git/,.gitignore,.gitmodules,.gitattributes"
+	defaultExcludes = "jpg,jpeg,gif,png,wmv,flv,tar.gz,zip"
+)
+
 // Storage manages artifacts
 type Storage struct {
 	// BasePath is the local directory path where the source artifacts are stored.
@@ -112,17 +118,22 @@ func (s *Storage) ArtifactExist(artifact sourcev1.Artifact) bool {
 	return true
 }
 
-// Archive creates a tar.gz to the artifact path from the given dir excluding the provided file extensions
-func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, excludes string, integrityCheck bool) error {
-	if excludes == "" {
-		excludes = "jpg,jpeg,gif,png,wmv,flv,tar.gz,zip"
-	}
-
+// Archive creates a tar.gz to the artifact path from the given dir excluding any VCS specific
+// files and directories, or any of the excludes defined in the excludeFiles.
+func (s *Storage) Archive(artifact sourcev1.Artifact, dir string, integrityCheck bool) error {
 	ctx, cancel := context.WithTimeout(context.Background(), s.Timeout)
 	defer cancel()
 
-	tarExcludes := fmt.Sprintf("--exclude=\\*.{%s} --exclude .git", excludes)
-	cmd := fmt.Sprintf("cd %s && tar -c %s -f - . | gzip > %s", dir, tarExcludes, artifact.Path)
+	var tarExcludes []string
+	if _, err := os.Stat(filepath.Join(dir, excludeFile)); os.IsNotExist(err) {
+		tarExcludes = append(tarExcludes, "--exclude-file="+excludeFile)
+	} else {
+		tarExcludes = append(tarExcludes, fmt.Sprintf("--exclude=\\*.{%s}", defaultExcludes))
+	}
+	for _, excl := range strings.Split(excludeVCS, ",") {
+		tarExcludes = append(tarExcludes, "--exclude="+excl)
+	}
+	cmd := fmt.Sprintf("cd %s && tar -c %s -f - . | gzip > %s", dir, strings.Join(tarExcludes, " "), artifact.Path)
 	command := exec.CommandContext(ctx, "/bin/sh", "-c", cmd)
 
 	err := command.Run()