database: add GetNamespace

Provides the functionality to retrieve a namespace from his name.

database/database.go

@@ -76,6 +76,9 @@ type Datastore interface {
 	// ListNamespaces returns the entire list of known Namespaces.
 	ListNamespaces() ([]Namespace, error)
 
+	//GetNamespace returns the namespace with name namespaceName
+	GetNamespace(namespaceName string) (*Namespace, error)
+
 	// InsertLayer stores a Layer in the database.
 	//
 	// A Layer is uniquely identified by its Name.

database/mock.go

@@ -20,6 +20,7 @@ import "time"
 // The default behavior of each method is to simply panic.
 type MockDatastore struct {
 	FctListNamespaces           func() ([]Namespace, error)
+	FctGetNamespace             func(namespaceName string) (*Namespace, error)
 	FctInsertLayer              func(Layer) error
 	FctFindLayer                func(name string, withFeatures, withVulnerabilities bool) (Layer, error)
 	FctDeleteLayer              func(name string) error
@@ -49,6 +50,13 @@ func (mds *MockDatastore) ListNamespaces() ([]Namespace, error) {
 	panic("required mock function not implemented")
 }
 
+func (mds *MockDatastore) GetNamespace(namespaceName string) (*Namespace, error) {
+	if mds.FctGetNamespace != nil {
+		return mds.FctGetNamespace(namespaceName)
+	}
+	panic("required mock function not implemented")
+}
+
 func (mds *MockDatastore) InsertLayer(layer Layer) error {
 	if mds.FctInsertLayer != nil {
 		return mds.FctInsertLayer(layer)

database/pgsql/namespace.go

@@ -73,3 +73,12 @@ func (pgSQL *pgSQL) ListNamespaces() (namespaces []database.Namespace, err error
 
 	return namespaces, err
 }
+
+func (pgSQL *pgSQL) GetNamespace(namespaceName string) (*database.Namespace, error) {
+	var ns database.Namespace
+	err := pgSQL.QueryRow(getNamespace, namespaceName).Scan(&ns.ID, &ns.Name, &ns.VersionFormat)
+	if err != nil {
+		return nil, handleError("getNamespace", err)
+	}
+	return &ns, nil
+}

database/pgsql/namespace_test.go

@@ -72,3 +72,22 @@ func TestListNamespace(t *testing.T) {
 		}
 	}
 }
+
+func TestGetNamespace(t *testing.T) {
+	datastore, err := openDatabaseForTest("GetNamespace", true)
+	if err != nil {
+		t.Error(err)
+		return
+	}
+	defer datastore.Close()
+
+	// Invalid Namespace.
+	ns0, err := datastore.GetNamespace("Not present")
+	assert.NotNil(t, err)
+	assert.Nil(t, ns0)
+
+	// Valid Namespace.
+	ns1, err := datastore.GetNamespace("debian:7")
+	assert.Nil(t, err)
+	assert.Equal(t, ns1.Name, "debian:7")
+}

database/pgsql/queries.go

@@ -40,6 +40,7 @@ const (
 
 	searchNamespace = `SELECT id FROM Namespace WHERE name = $1`
 	listNamespace   = `SELECT id, name, version_format FROM Namespace`
+	getNamespace    = `SELECT id, name, version_format FROM Namespace WHERE name = $1`
 
 	// feature.go
 	soiFeature = `