Add slow-start support in vs/vsr

docs/virtualserver-and-virtualserverroute.md

@@ -217,6 +217,7 @@ tls:
 | `client-max-body-size` | Sets the maximum allowed size of the client request body. See the [client_max_body_size](https://nginx.org/en/docs/http/ngx_http_core_module.html#client_max_body_size) directive. The default is set in the `client-max-body-size` ConfigMap key. | `string` | No |
 | `tls` | The TLS configuration for the Upstream. | [`tls`](#UpstreamTLS) | No |
 | `healthCheck` | The health check configuration for the Upstream. See the [health_check](http://nginx.org/en/docs/http/ngx_http_upstream_hc_module.html#health_check) directive. Note: this feature is supported only in NGINX Plus. | [`healthcheck`](#UpstreamHealthcheck) | No |
+| `slow-start` | The slow start allows an upstream server to gradually recover its weight from 0 to its nominal value after it has been recovered or became available or when the server becomes available after a period of time it was considered unavailable. By default, the slow start is disabled. See the [slow_start](https://nginx.org/en/docs/http/ngx_http_upstream_module.html#slow_start) parameter of the server directive. Note: The parameter cannot be used along with the `random`, `hash` or `ip_hash` load balancing methods and will be ignored. | `string` | No |
 
 ### Upstream.TLS
 

internal/configs/version2/config.go

@@ -25,6 +25,7 @@ type UpstreamServer struct {
 	MaxConns    int
 	FailTimeout string
 	Resolve     bool
+	SlowStart   string
 }
 
 // Server defines a server.

internal/configs/version2/nginx-plus.virtualserver.tmpl

@@ -5,7 +5,7 @@ upstream {{ $u.Name }} {
     {{ if $u.LBMethod }}{{ $u.LBMethod }};{{ end }}
 
     {{ range $s := $u.Servers }}
-    server {{ $s.Address }} max_fails={{ $s.MaxFails }} fail_timeout={{ $s.FailTimeout }} max_conns={{ $s.MaxConns }}{{ if $s.Resolve }} resolve{{ end }};
+    server {{ $s.Address }} max_fails={{ $s.MaxFails }} fail_timeout={{ $s.FailTimeout }}{{ if $s.SlowStart }} slow_start={{ $s.SlowStart }}{{ end }} max_conns={{ $s.MaxConns }}{{ if $s.Resolve }} resolve{{ end }};
     {{ end }}
 
     {{ if $u.Keepalive }}

internal/configs/version2/templates_test.go

@@ -15,6 +15,7 @@ var virtualServerCfg = VirtualServerConfig{
 					MaxFails:    5,
 					FailTimeout: "10s",
 					MaxConns:    31,
+					SlowStart:   "10s",
 				},
 			},
 			LBMethod:         "random",

internal/configs/virtualserver.go

@@ -14,6 +14,15 @@ import (
 
 const nginx502Server = "unix:/var/run/nginx-502-server.sock"
 
+var incompatibleLBMethodsForSlowStart = map[string]bool{
+	"random":                          true,
+	"ip_hash":                         true,
+	"random two":                      true,
+	"random two least_conn":           true,
+	"random two least_time=header":    true,
+	"random two least_time=last_byte": true,
+}
+
 // VirtualServerEx holds a VirtualServer along with the resources that are referenced in this VirtualServer.
 type VirtualServerEx struct {
 	VirtualServer       *conf_v1alpha1.VirtualServer
@@ -211,7 +220,7 @@ func generateVirtualServerConfig(virtualServerEx *VirtualServerEx, tlsPemFileNam
 		endpoints := generateEndpointsForUpstream(upstreamNamespace, u, virtualServerEx, isResolverConfigured, isPlus)
 		// isExternalNameSvc is always false for OSS
 		_, isExternalNameSvc := virtualServerEx.ExternalNameSvcs[GenerateExternalNameSvcKey(upstreamNamespace, u.Service)]
-		ups := generateUpstream(upstreamName, u, isExternalNameSvc, endpoints, baseCfgParams)
+		ups := generateUpstream(upstreamName, u, isExternalNameSvc, endpoints, baseCfgParams, isPlus)
 		upstreams = append(upstreams, ups)
 		crUpstreams[upstreamName] = u
 
@@ -231,7 +240,7 @@ func generateVirtualServerConfig(virtualServerEx *VirtualServerEx, tlsPemFileNam
 			endpoints := generateEndpointsForUpstream(upstreamNamespace, u, virtualServerEx, isResolverConfigured, isPlus)
 			// isExternalNameSvc is always false for OSS
 			_, isExternalNameSvc := virtualServerEx.ExternalNameSvcs[GenerateExternalNameSvcKey(upstreamNamespace, u.Service)]
-			ups := generateUpstream(upstreamName, u, isExternalNameSvc, endpoints, baseCfgParams)
+			ups := generateUpstream(upstreamName, u, isExternalNameSvc, endpoints, baseCfgParams, isPlus)
 			upstreams = append(upstreams, ups)
 			crUpstreams[upstreamName] = u
 
@@ -332,8 +341,9 @@ func generateVirtualServerConfig(virtualServerEx *VirtualServerEx, tlsPemFileNam
 	}
 }
 
-func generateUpstream(upstreamName string, upstream conf_v1alpha1.Upstream, isExternalNameSvc bool, endpoints []string, cfgParams *ConfigParams) version2.Upstream {
+func generateUpstream(upstreamName string, upstream conf_v1alpha1.Upstream, isExternalNameSvc bool, endpoints []string, cfgParams *ConfigParams, isPlus bool) version2.Upstream {
 	var upsServers []version2.UpstreamServer
+	lbMethod := generateLBMethod(upstream.LBMethod, cfgParams.LBMethod)
 
 	for _, e := range endpoints {
 		s := version2.UpstreamServer{
@@ -343,18 +353,41 @@ func generateUpstream(upstreamName string, upstream conf_v1alpha1.Upstream, isEx
 			MaxConns:    generateIntFromPointer(upstream.MaxConns, cfgParams.MaxConns),
 			Resolve:     isExternalNameSvc,
 		}
+
+		if isPlus {
+			s.SlowStart = generateSlowStartForPlus(upstream, lbMethod)
+		}
+
 		upsServers = append(upsServers, s)
 	}
 
 	return version2.Upstream{
 		Name:             upstreamName,
 		Servers:          upsServers,
-		LBMethod:         generateLBMethod(upstream.LBMethod, cfgParams.LBMethod),
+		LBMethod:         lbMethod,
 		Keepalive:        generateIntFromPointer(upstream.Keepalive, cfgParams.Keepalive),
 		UpstreamZoneSize: cfgParams.UpstreamZoneSize,
 	}
 }
 
+func generateSlowStartForPlus(upstream conf_v1alpha1.Upstream, lbMethod string) string {
+	if upstream.SlowStart == "" {
+		return ""
+	}
+
+	if strings.HasPrefix(lbMethod, "hash") {
+		glog.Warningf("slow-start will be disabled for the Upstream %v", upstream.Name)
+		return ""
+	}
+
+	if _, exists := incompatibleLBMethodsForSlowStart[lbMethod]; exists {
+		glog.Warningf("slow-start will be disabled for the Upstream %v", upstream.Name)
+		return ""
+	}
+
+	return upstream.SlowStart
+}
+
 func generateLBMethod(method string, defaultMethod string) string {
 	if method == "" {
 		return defaultMethod

internal/configs/virtualserver_test.go

@@ -767,7 +767,7 @@ func TestGenerateVirtualServerConfigForVirtualServerWithRules(t *testing.T) {
 
 func TestGenerateUpstream(t *testing.T) {
 	name := "test-upstream"
-	upstream := conf_v1alpha1.Upstream{Service: name, Port: 80}
+	upstream := conf_v1alpha1.Upstream{Service: name, Port: 80, SlowStart: "10s"}
 	endpoints := []string{
 		"192.168.10.10:8080",
 	}
@@ -788,14 +788,15 @@ func TestGenerateUpstream(t *testing.T) {
 				MaxFails:    1,
 				MaxConns:    0,
 				FailTimeout: "10s",
+				SlowStart:   "",
 			},
 		},
 		LBMethod:         "random",
 		Keepalive:        21,
 		UpstreamZoneSize: "256k",
 	}
 
-	result := generateUpstream(name, upstream, false, endpoints, &cfgParams)
+	result := generateUpstream(name, upstream, false, endpoints, &cfgParams, true)
 	if !reflect.DeepEqual(result, expected) {
 		t.Errorf("generateUpstream() returned %v but expected %v", result, expected)
 	}
@@ -859,7 +860,7 @@ func TestGenerateUpstreamWithKeepalive(t *testing.T) {
 	}
 
 	for _, test := range tests {
-		result := generateUpstream(name, test.upstream, false, endpoints, test.cfgParams)
+		result := generateUpstream(name, test.upstream, false, endpoints, test.cfgParams, false)
 		if !reflect.DeepEqual(result, test.expected) {
 			t.Errorf("generateUpstream() returned %v but expected %v for the case of %v", result, test.expected, test.msg)
 		}
@@ -882,7 +883,7 @@ func TestGenerateUpstreamForExternalNameService(t *testing.T) {
 		},
 	}
 
-	result := generateUpstream(name, upstream, true, endpoints, &cfgParams)
+	result := generateUpstream(name, upstream, true, endpoints, &cfgParams, false)
 	if !reflect.DeepEqual(result, expected) {
 		t.Errorf("generateUpstream() returned %v but expected %v", result, expected)
 	}
@@ -1962,3 +1963,56 @@ func TestGenerateEndpointsForUpstream(t *testing.T) {
 		}
 	}
 }
+
+func TestGenerateSlowStartForPlusWithInCompatibleLBMethods(t *testing.T) {
+	serviceName := "test-slowstart-with-incompatible-LBMethods"
+	upstream := conf_v1alpha1.Upstream{Service: serviceName, Port: 80, SlowStart: "10s"}
+	expected := ""
+
+	var tests = []string{
+		"random",
+		"ip_hash",
+		"hash 123",
+		"random two",
+		"random two least_conn",
+		"random two least_time=header",
+		"random two least_time=last_byte",
+	}
+
+	for _, lbMethod := range tests {
+		result := generateSlowStartForPlus(upstream, lbMethod)
+
+		if !reflect.DeepEqual(result, expected) {
+			t.Errorf("generateSlowStartForPlus returned %v, but expected %v for lbMethod %v", result, expected, lbMethod)
+		}
+	}
+
+}
+
+func TestGenerateSlowStartForPlus(t *testing.T) {
+	serviceName := "test-slowstart"
+
+	tests := []struct {
+		upstream conf_v1alpha1.Upstream
+		lbMethod string
+		expected string
+	}{
+		{
+			upstream: conf_v1alpha1.Upstream{Service: serviceName, Port: 80, SlowStart: "", LBMethod: "least_conn"},
+			lbMethod: "least_conn",
+			expected: "",
+		},
+		{
+			upstream: conf_v1alpha1.Upstream{Service: serviceName, Port: 80, SlowStart: "10s", LBMethod: "least_conn"},
+			lbMethod: "least_conn",
+			expected: "10s",
+		},
+	}
+
+	for _, test := range tests {
+		result := generateSlowStartForPlus(test.upstream, test.lbMethod)
+		if !reflect.DeepEqual(result, test.expected) {
+			t.Errorf("generateSlowStartForPlus returned %v, but expected %v", result, test.expected)
+		}
+	}
+}

pkg/apis/configuration/v1alpha1/types.go

@@ -42,6 +42,7 @@ type Upstream struct {
 	ClientMaxBodySize        string       `json:"client-max-body-size"`
 	TLS                      UpstreamTLS  `json:"tls"`
 	HealthCheck              *HealthCheck `json:"healthCheck"`
+	SlowStart                string       `json:"slow-start"`
 }
 
 // UpstreamTLS defines a TLS configuration for an Upstream.

pkg/apis/configuration/validation/validation.go

@@ -331,6 +331,7 @@ func validateUpstreams(upstreams []v1alpha1.Upstream, fieldPath *field.Path, isP
 		allErrs = append(allErrs, validatePositiveIntOrZeroFromPointer(u.MaxConns, idxPath.Child("max-conns"))...)
 		allErrs = append(allErrs, validateSize(u.ClientMaxBodySize, idxPath.Child("client-max-body-size"))...)
 		allErrs = append(allErrs, validateUpstreamHealthCheck(u.HealthCheck, idxPath.Child("healthCheck"))...)
+		allErrs = append(allErrs, validateTime(u.SlowStart, idxPath.Child("slow-start"))...)
 
 		for _, msg := range validation.IsValidPortNum(int(u.Port)) {
 			allErrs = append(allErrs, field.Invalid(idxPath.Child("port"), u.Port, msg))