Handle uncommon format of proper tar archive

Provide proper handling of tar archives containing
"current directory", but stored in format:
```
.
file2.txt
dir1/
dir1/file1.txt
```
instead of typical:
```
./
./file2.txt
./dir1/
./dir1/file1.txt
```

Issue-ID: MULTICLOUD-1025
Signed-off-by: Konrad Bańka <k.banka@samsung.com>
Change-Id: Ideffd019255a9f2d029527066e5a6a03d45a2d7b

2 files changed, 46 insertions, 2 deletions

diff --git a/src/k8splugin/internal/rb/archive.go b/src/k8splugin/internal/rb/archive.go
index c0753134..267c7cd2 100644
--- a/src/k8splugin/internal/rb/archive.go
+++ b/src/k8splugin/internal/rb/archive.go
@@ -115,6 +115,10 @@ func ExtractTarBall(r io.Reader) (string, error) {
 				}
 			}
 		case tar.TypeReg:
+			if target == outDir { // Handle '.' substituted to '' entry
+				continue
+			}
+
 			err = utils.EnsureDirectory(target)
 			if err != nil {
 				return "", pkgerrors.Wrap(err, "Creating Directory")
diff --git a/src/k8splugin/internal/rb/archive_test.go b/src/k8splugin/internal/rb/archive_test.go
index 5fa66e79..4c09069a 100644
--- a/src/k8splugin/internal/rb/archive_test.go
+++ b/src/k8splugin/internal/rb/archive_test.go
@@ -19,6 +19,7 @@ package rb
 import (
 	"bytes"
 	"io/ioutil"
+	"os"
 	"path/filepath"
 	"strings"
 	"testing"
@@ -102,6 +103,7 @@ func TestExtractTarBall(t *testing.T) {
 		}
 
 		path, err := ExtractTarBall(bytes.NewBuffer(content))
+		defer os.RemoveAll(path)
 		if err != nil {
 			t.Errorf("Error reading valid tar.gz file %s", err.Error())
 		}
@@ -120,7 +122,8 @@ func TestExtractTarBall(t *testing.T) {
 			0x00, 0xff, 0xf2, 0x48, 0xcd,
 		}
 
-		_, err := ExtractTarBall(bytes.NewBuffer(content))
+		path, err := ExtractTarBall(bytes.NewBuffer(content))
+		defer os.RemoveAll(path)
 		if err == nil {
 			t.Errorf("Error should NOT be nil")
 		}
@@ -128,9 +131,46 @@ func TestExtractTarBall(t *testing.T) {
 
 	t.Run("Empty tar.gz", func(t *testing.T) {
 		content := []byte{}
-		err := isTarGz(bytes.NewBuffer(content))
+		path, err := ExtractTarBall(bytes.NewBuffer(content))
+		defer os.RemoveAll(path)
 		if err == nil {
 			t.Errorf("Error should NOT be nil")
 		}
 	})
+
+	t.Run("Specific tar.gz with '.' entry", func(t *testing.T) {
+		content := []byte{
+			0x1f, 0x8b, 0x08, 0x00, 0x00, 0x00, 0x00, 0x00,
+			0x00, 0xff, 0xed, 0x94, 0xcd, 0x0a, 0xc3, 0x20,
+			0x10, 0x84, 0x3d, 0xfb, 0x14, 0x4b, 0xee, 0x29,
+			0x6b, 0x4c, 0x14, 0x7c, 0x99, 0x22, 0xd4, 0x42,
+			0x20, 0x3f, 0x25, 0x9a, 0x40, 0xde, 0x3e, 0x92,
+			0x9c, 0x1a, 0x0a, 0x39, 0x34, 0xb1, 0x87, 0xee,
+			0x77, 0x51, 0xd6, 0xc3, 0x8c, 0x8c, 0x23, 0x63,
+			0xd7, 0x83, 0x02, 0x51, 0x95, 0x25, 0xe0, 0xc6,
+			0x7e, 0x5d, 0xf7, 0x42, 0x2a, 0x89, 0x65, 0xa5,
+			0xb1, 0x2a, 0xe2, 0x5c, 0x2b, 0x2c, 0x18, 0x60,
+			0x02, 0x6f, 0x6c, 0xf4, 0xc1, 0x0e, 0x0c, 0xbf,
+			0xd6, 0xda, 0x5f, 0xee, 0x04, 0x6b, 0x29, 0x68,
+			0x6d, 0x57, 0x3f, 0x9d, 0x0f, 0xb7, 0xd9, 0xb6,
+			0xcd, 0x45, 0x1a, 0x87, 0xf9, 0x2b, 0xfd, 0x9e,
+			0xbf, 0x28, 0x24, 0x6a, 0xca, 0x3f, 0x05, 0x79,
+			0x9e, 0xf3, 0xc9, 0x0d, 0xbe, 0xee, 0x3b, 0x03,
+			0x93, 0xe0, 0x61, 0x7e, 0x39, 0xc3, 0x01, 0x26,
+			0xdb, 0x8c, 0xce, 0x1b, 0xc8, 0xfa, 0x78, 0x3a,
+			0xd4, 0x0f, 0x77, 0xdf, 0x26, 0xeb, 0x3b, 0xc9,
+			0xf8, 0xaf, 0x6d, 0x13, 0x27, 0xf1, 0x29, 0xde,
+			0xb3, 0x35, 0x0e, 0xfb, 0x2f, 0xd4, 0xae, 0xff,
+			0x52, 0x69, 0x41, 0xfd, 0x4f, 0x41, 0x88, 0x7f,
+			0xff, 0x96, 0xbd, 0x01, 0x4d, 0xb5, 0x26, 0x08,
+			0x82, 0xf8, 0x1b, 0x16, 0xb6, 0x17, 0x45, 0x61,
+			0x00, 0x0e, 0x00, 0x00,
+		}
+
+		path, err := ExtractTarBall(bytes.NewBuffer(content))
+		defer os.RemoveAll(path)
+		if err != nil {
+			t.Errorf("This tar.gz should be handled correctly, but '%s' occured", err)
+		}
+	})
 }