add validating configs from configuration file

Signed-off-by: allencloud <allen.sun@daocloud.io>

daemon/config.go

@@ -164,6 +164,11 @@ func ReloadConfiguration(configFile string, flags *flag.FlagSet, reload func(*Co
 	if err != nil {
 		return err
 	}
+
+	if err := validateConfiguration(newConfig); err != nil {
+		return fmt.Errorf("file configuration validation failed (%v)", err)
+	}
+
 	reload(newConfig)
 	return nil
 }
@@ -184,6 +189,10 @@ func MergeDaemonConfigurations(flagsConfig *Config, flags *flag.FlagSet, configF
 		return nil, err
 	}
 
+	if err := validateConfiguration(fileConfig); err != nil {
+		return nil, fmt.Errorf("file configuration validation failed (%v)", err)
+	}
+
 	// merge flags configuration on top of the file configuration
 	if err := mergo.Merge(fileConfig, flagsConfig); err != nil {
 		return nil, err
@@ -336,3 +345,30 @@ func findConfigurationConflicts(config map[string]interface{}, flags *flag.FlagS
 	}
 	return nil
 }
+
+// validateConfiguration validates some specific configs.
+// such as config.DNS, config.Labels, config.DNSSearch
+func validateConfiguration(config *Config) error {
+	// validate DNS
+	for _, dns := range config.DNS {
+		if _, err := opts.ValidateIPAddress(dns); err != nil {
+			return err
+		}
+	}
+
+	// validate DNSSearch
+	for _, dnsSearch := range config.DNSSearch {
+		if _, err := opts.ValidateDNSSearch(dnsSearch); err != nil {
+			return err
+		}
+	}
+
+	// validate Labels
+	for _, label := range config.Labels {
+		if _, err := opts.ValidateLabel(label); err != nil {
+			return err
+		}
+	}
+
+	return nil
+}

daemon/config_test.go

@@ -208,3 +208,71 @@ func TestFindConfigurationConflictsWithMergedValues(t *testing.T) {
 		t.Fatalf("expected hosts conflict, got %v", err)
 	}
 }
+
+func TestValidateConfiguration(t *testing.T) {
+	c1 := &Config{
+		CommonConfig: CommonConfig{
+			Labels: []string{"one"},
+		},
+	}
+
+	err := validateConfiguration(c1)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+
+	c2 := &Config{
+		CommonConfig: CommonConfig{
+			Labels: []string{"one=two"},
+		},
+	}
+
+	err = validateConfiguration(c2)
+	if err != nil {
+		t.Fatalf("expected no error, got error %v", err)
+	}
+
+	c3 := &Config{
+		CommonConfig: CommonConfig{
+			DNS: []string{"1.1.1.1"},
+		},
+	}
+
+	err = validateConfiguration(c3)
+	if err != nil {
+		t.Fatalf("expected no error, got error %v", err)
+	}
+
+	c4 := &Config{
+		CommonConfig: CommonConfig{
+			DNS: []string{"1.1.1.1o"},
+		},
+	}
+
+	err = validateConfiguration(c4)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+
+	c5 := &Config{
+		CommonConfig: CommonConfig{
+			DNSSearch: []string{"a.b.c"},
+		},
+	}
+
+	err = validateConfiguration(c5)
+	if err != nil {
+		t.Fatalf("expected no error, got error %v", err)
+	}
+
+	c6 := &Config{
+		CommonConfig: CommonConfig{
+			DNSSearch: []string{"123456"},
+		},
+	}
+
+	err = validateConfiguration(c6)
+	if err == nil {
+		t.Fatal("expected error, got nil")
+	}
+}