feat: add cache argument

cache/cache_test.go

@@ -0,0 +1,31 @@
+package cache
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+	"testing"
+
+	"code.dumpstack.io/tools/out-of-tree/fs"
+)
+
+func TestDownloadQemuImage(t *testing.T) {
+
+	tmp, err := ioutil.TempDir("", "out-of-tree_")
+	if err != nil {
+		return
+	}
+	defer os.RemoveAll(tmp)
+
+	URL = "https://out-of-tree.fra1.digitaloceanspaces.com/1.0.0/"
+	file := "out_of_tree_ubuntu_12__04.img"
+
+	err = DownloadQemuImage(tmp, file)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if !fs.PathExists(filepath.Join(tmp, file)) {
+		t.Fatalf("%s does not exist", file)
+	}
+}