support for default_backend

docs/usage.md

@@ -21,6 +21,7 @@ The following query parameters can be used to send a *reconfigure* request to *D
 |delReqHeader   |Additional headers that will be deleted in the request before forwarding it to the service. Multiple headers should be separated with comma (`,`). Please consult [Delete a header in the request](https://www.haproxy.com/doc/aloha/7.0/haproxy/http_rewriting.html#delete-a-header-in-the-request) for more info.<br>Example: `X-Forwarded-For,Cookie`|No| |
 |delResHeader   |Additional headers that will be deleted in the response before forwarding it to the client. Multiple headers should be separated with comma (`,`). Please consult [Delete a header in the response](https://www.haproxy.com/doc/aloha/7.0/haproxy/http_rewriting.html#delete-a-header-in-the-response) for more info.<br>Example: `X-Varnish,X-Cache`|No| |
 |httpsPort      |The internal HTTPS port of a service that should be reconfigured. The port is used only in the `swarm` mode. If not specified, the `port` parameter will be used instead.<br>Example: `443`|No| |
+|isDefaultBackend  | If true, the service will be set to the default_backend rule, meaning it will catch all requests not matching any other rules.<br>Example: `true`|No| |
 |port           |The internal port of a service that should be reconfigured. The port is used only in the `swarm` mode. The parameter can be prefixed with an index thus allowing definition of multiple destinations for a single service (e.g. `port.1`, `port.2`, and so on).<br>Example: `8080`|Only in `swarm` mode.| |
 |reqMode        |The request mode. The proxy should be able to work with any mode supported by HAProxy. However, actively supported and tested modes are `http`, `tcp`, and `sni`. The `sni` mode implies TCP with an SNI-based routing.<br>Example: `tcp`|No|http|
 |reqPathReplace |A regular expression to apply the modification. If specified, `reqPathSearch` needs to be set as well.<br>Example: `/demo/`|No| |

proxy/ha_proxy.go

@@ -432,6 +432,11 @@ func (m *HaProxy) getFrontTemplate(s Service) string {
 	} else {
 		tmplString += `use_backend {{$.ServiceName}}-be{{.Port}} if url_{{$.AclName}}{{.Port}}{{$.AclCondition}}{{.SrcPortAclName}}`
 	}
+	if s.IsDefaultBackend {
+		tmplString += fmt.Sprintf(
+			`
+    default_backend {{$.ServiceName}}-be{{.Port}}`)
+	}
 	tmplString += "{{end}}"
 	return m.templateToString(tmplString, s)
 }

proxy/ha_proxy_test.go

@@ -877,6 +877,38 @@ func (s HaProxyTestSuite) Test_CreateConfigFromTemplates_AddsContentFrontEndWith
 	s.Equal(expectedData, actualData)
 }
 
+
+func (s HaProxyTestSuite) Test_CreateConfigFromTemplates_AddsContentFrontEndWithDefaultBackend_WhenIsDefaultBackendIsTrue() {
+	var actualData string
+	tmpl := s.TemplateContent
+	expectedData := fmt.Sprintf(
+		`%s
+    acl url_my-service1111 path_beg /path
+    use_backend my-service-be1111 if url_my-service1111
+    default_backend my-service-be1111%s`,
+		tmpl,
+		s.ServicesContent,
+	)
+	writeFile = func(filename string, data []byte, perm os.FileMode) error {
+		actualData = string(data)
+		return nil
+	}
+	p := NewHaProxy(s.TemplatesPath, s.ConfigsPath)
+	data.Services["my-service"] = Service{
+		ServiceName:           "my-service",
+		IsDefaultBackend:      true,
+		AclName:               "my-service",
+		PathType:              "path_beg",
+		ServiceDest: []ServiceDest{
+			{Port: "1111", ServicePath: []string{"/path"}},
+		},
+	}
+
+	p.CreateConfigFromTemplates()
+
+	s.Equal(expectedData, actualData)
+}
+
 func (s HaProxyTestSuite) Test_CreateConfigFromTemplates_AddsContentFrontEndWithHdrDom_WhenServiceDomainMatchAllIsSet() {
 	var actualData string
 	tmpl := s.TemplateContent

proxy/types.go

@@ -67,6 +67,8 @@ type Service struct {
 	// The port is used only in the swarm mode.
 	// If not specified, the `port` parameter will be used instead.
 	HttpsPort int `split_words:"true"`
+	// If set to true, it will be the default_backend service.
+	IsDefaultBackend bool `envconfig:"default_backend" split_words:"true"`
 	// The hostname where the service is running, for instance on a separate swarm.
 	// If specified, the proxy will dispatch requests to that domain.
 	OutboundHostname string `split_words:"true"`

proxy/types_test.go

@@ -177,6 +177,7 @@ func (s *TypesTestSuite) Test_GetServiceFromMap_ReturnsProxyService() {
 		Distribute:            true,
 		HttpsOnly:             true,
 		HttpsPort:             1234,
+		IsDefaultBackend:      true,
 		OutboundHostname:      "outboundHostname",
 		PathType:              "pathType",
 		RedirectWhenHttpProto: true,
@@ -235,6 +236,7 @@ func (s *TypesTestSuite) Test_GetServiceFromMap_ReturnsProxyService() {
 		"delResHeader":          strings.Join(expected.DelResHeader, ","),
 		"port":                  expected.ServiceDest[0].Port,
 		"servicePath":           strings.Join(expected.ServiceDest[0].ServicePath, ","),
+		"isDefaultBackend": strconv.FormatBool(expected.IsDefaultBackend),
 	}
 	actual := GetServiceFromMap(&serviceMap)
 	s.Equal(expected, *actual)

server/server_test.go

@@ -726,6 +726,7 @@ func (s *ServerTestSuite) Test_GetServicesFromEnvVars_ReturnsServices() {
 		Distribute:            true,
 		HttpsOnly:             true,
 		HttpsPort:             1234,
+		IsDefaultBackend:      true,
 		OutboundHostname:      "my-OutboundHostname",
 		PathType:              "my-PathType",
 		RedirectWhenHttpProto: true,
@@ -759,6 +760,7 @@ func (s *ServerTestSuite) Test_GetServicesFromEnvVars_ReturnsServices() {
 	os.Setenv("DFP_SERVICE_DISTRIBUTE", strconv.FormatBool(service.Distribute))
 	os.Setenv("DFP_SERVICE_HTTPS_ONLY", strconv.FormatBool(service.HttpsOnly))
 	os.Setenv("DFP_SERVICE_HTTPS_PORT", strconv.Itoa(service.HttpsPort))
+	os.Setenv("DFP_SERVICE_DEFAULT_BACKEND", strconv.FormatBool(service.IsDefaultBackend))
 	os.Setenv("DFP_SERVICE_OUTBOUND_HOSTNAME", service.OutboundHostname)
 	os.Setenv("DFP_SERVICE_PATH_TYPE", service.PathType)
 	os.Setenv("DFP_SERVICE_REDIRECT_WHEN_HTTP_PROTO", strconv.FormatBool(service.RedirectWhenHttpProto))
@@ -789,6 +791,7 @@ func (s *ServerTestSuite) Test_GetServicesFromEnvVars_ReturnsServices() {
 		os.Unsetenv("DFP_SERVICE_CONNECTION_MODE")
 		os.Unsetenv("DFP_SERVICE_CONSUL_TEMPLATE_BE_PATH")
 		os.Unsetenv("DFP_SERVICE_CONSUL_TEMPLATE_FE_PATH")
+		os.Unsetenv("DFP_SERVICE_DEFAULT_BACKEND")
 		os.Unsetenv("DFP_SERVICE_DEL_REQ_HEADER")
 		os.Unsetenv("DFP_SERVICE_DEL_RES_HEADER")
 		os.Unsetenv("DFP_SERVICE_DISTRIBUTE")