Always output the default header when saving ini file (#476)

vault/config.go

@@ -36,6 +36,7 @@ const (
 )
 
 func init() {
+	ini.DefaultHeader = true
 	ini.PrettyFormat = false
 }
 
@@ -201,6 +202,10 @@ func (c *ConfigFile) ProfileSection(name string) (ProfileSection, bool) {
 	return profile, true
 }
 
+func (c *ConfigFile) Save() error {
+	return c.iniFile.SaveTo(c.Path)
+}
+
 // Add the profile to the configuration file
 func (c *ConfigFile) Add(profile ProfileSection) error {
 	if c.iniFile == nil {
@@ -218,7 +223,7 @@ func (c *ConfigFile) Add(profile ProfileSection) error {
 	if err = section.ReflectFrom(&profile); err != nil {
 		return fmt.Errorf("Error mapping profile to ini file: %v", err)
 	}
-	return c.iniFile.SaveTo(c.Path)
+	return c.Save()
 }
 
 // ProfileNames returns a slice of profile names from the AWS config

vault/config_test.go

@@ -40,7 +40,9 @@ region=us-east-1
 parent_profile=testparentprofile1
 `)
 
-var nestedConfig = []byte(`[profile testing]
+var nestedConfig = []byte(`[default]
+
+[profile testing]
 aws_access_key_id=foo
 aws_secret_access_key=bar
 region=us-west-2
@@ -49,6 +51,17 @@ s3=
   max_queue_size=1000
 `)
 
+var defaultsOnlyConfigWithHeader = []byte(`[default]
+region=us-west-2
+output=json
+
+`)
+
+var defaultsOnlyConfigWithoutHeader = []byte(`region=us-west-2
+output=json
+
+`)
+
 func newConfigFile(t *testing.T, b []byte) string {
 	f, err := ioutil.TempFile("", "aws-config")
 	if err != nil {
@@ -276,3 +289,50 @@ func TestProfileIsEmpty(t *testing.T) {
 		t.Errorf("Expected p to be empty")
 	}
 }
+
+func TestIniWithHeaderSavesWithHeader(t *testing.T) {
+	f := newConfigFile(t, defaultsOnlyConfigWithHeader)
+	defer os.Remove(f)
+
+	cfg, err := vault.LoadConfig(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = cfg.Save()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := defaultsOnlyConfigWithHeader
+
+	b, _ := ioutil.ReadFile(f)
+
+	if !bytes.Equal(expected, b) {
+		t.Fatalf("Expected:\n%q\nGot:\n%q", expected, b)
+	}
+
+}
+
+func TestIniWithoutHeaderSavesWithHeader(t *testing.T) {
+	f := newConfigFile(t, defaultsOnlyConfigWithoutHeader)
+	defer os.Remove(f)
+
+	cfg, err := vault.LoadConfig(f)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	err = cfg.Save()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	expected := defaultsOnlyConfigWithHeader
+
+	b, _ := ioutil.ReadFile(f)
+
+	if !bytes.Equal(expected, b) {
+		t.Fatalf("Expected:\n%q\nGot:\n%q", expected, b)
+	}
+}