add ip generator for file

Signed-off-by: Chanwit Kaewkasi <chanwit@gmail.com>

discovery/file/file.go

@@ -23,13 +23,22 @@ func (s *FileDiscoveryService) Initialize(path string, heartbeat int) error {
 	return nil
 }
 
+func parseFileContent(content []byte) []string {
+	result := make([]string, 0)
+	for _, line := range strings.Split(strings.TrimSpace(string(content)), "\n") {
+		for _, ip := range discovery.Generate(line) {
+			result = append(result, ip)
+		}
+	}
+	return result
+}
+
 func (s *FileDiscoveryService) Fetch() ([]*discovery.Entry, error) {
-	data, err := ioutil.ReadFile(s.path)
+	fileContent, err := ioutil.ReadFile(s.path)
 	if err != nil {
 		return nil, err
 	}
-
-	return discovery.CreateEntries(strings.Split(string(data), "\n"))
+	return discovery.CreateEntries(parseFileContent(fileContent))
 }
 
 func (s *FileDiscoveryService) Watch(callback discovery.WatchCallback) {

discovery/file/file_test.go

@@ -12,6 +12,19 @@ func TestInitialize(t *testing.T) {
 	assert.Equal(t, discovery.path, "/path/to/file")
 }
 
+func TestContent(t *testing.T) {
+	data := `
+1.1.1.[1:2]:1111
+2.2.2.[2:4]:2222
+`
+	ips := parseFileContent([]byte(data))
+	assert.Equal(t, ips[0], "1.1.1.1:1111")
+	assert.Equal(t, ips[1], "1.1.1.2:1111")
+	assert.Equal(t, ips[2], "2.2.2.2:2222")
+	assert.Equal(t, ips[3], "2.2.2.3:2222")
+	assert.Equal(t, ips[4], "2.2.2.4:2222")
+}
+
 func TestRegister(t *testing.T) {
 	discovery := &FileDiscoveryService{path: "/path/to/file"}
 	assert.Error(t, discovery.Register("0.0.0.0"))