2 files changed, 66 insertions, 0 deletions
diff --git a/config/modules.go b/config/modules.go
new file mode 100644
index 0000000..3f095fa
--- /dev/null
+++ b/config/modules.go
@@ -0,0 +1,43 @@
+package config
+
+import "errors"
+
+var (
+	ErrModuleEmptyURL  = errors.New("module config: empty URL")
+	ErrModuleEmptyPath = errors.New("module config: empty path")
+)
+
+const DefaultModuleBranch = "master"
+
+// Modules defines the submodules properties
+type Modules map[string]*Module
+
+// Module defines a submodule
+// https://www.kernel.org/pub/software/scm/git/docs/gitmodules.html
+type Module struct {
+	// Path defines the path, relative to the top-level directory of the Git
+	// working tree,
+	Path string
+	// URL defines a URL from which the submodule repository can be cloned.
+	URL string
+	// Branch is a remote branch name for tracking updates in the upstream
+	// submodule.
+	Branch string
+}
+
+// Validate validate the fields and set the default values
+func (m *Module) Validate() error {
+	if m.Path == "" {
+		return ErrModuleEmptyPath
+	}
+
+	if m.URL == "" {
+		return ErrModuleEmptyURL
+	}
+
+	if m.Branch == "" {
+		m.Branch = DefaultModuleBranch
+	}
+
+	return nil
+}
diff --git a/config/modules_test.go b/config/modules_test.go
new file mode 100644
index 0000000..50b5691
--- /dev/null
+++ b/config/modules_test.go
@@ -0,0 +1,23 @@
+package config
+
+import . "gopkg.in/check.v1"
+
+type ModuleSuite struct{}
+
+var _ = Suite(&ModuleSuite{})
+
+func (s *ModuleSuite) TestModuleValidateMissingURL(c *C) {
+	m := &Module{Path: "foo"}
+	c.Assert(m.Validate(), Equals, ErrModuleEmptyURL)
+}
+
+func (s *ModuleSuite) TestModuleValidateMissingName(c *C) {
+	m := &Module{URL: "bar"}
+	c.Assert(m.Validate(), Equals, ErrModuleEmptyPath)
+}
+
+func (s *ModuleSuite) TestModuleValidateDefault(c *C) {
+	m := &Module{Path: "foo", URL: "http://foo/bar"}
+	c.Assert(m.Validate(), IsNil)
+	c.Assert(m.Branch, Equals, DefaultModuleBranch)
+}