[nginx-ingress-controller] Add support for rate limiting in ingress rule locations

ingress/controllers/nginx/controller.go

@@ -42,6 +42,7 @@ import (
 
 	"k8s.io/contrib/ingress/controllers/nginx/healthcheck"
 	"k8s.io/contrib/ingress/controllers/nginx/nginx"
+	"k8s.io/contrib/ingress/controllers/nginx/nginx/ratelimit"
 	"k8s.io/contrib/ingress/controllers/nginx/nginx/rewrite"
 )
 
@@ -583,6 +584,12 @@ func (lbc *loadBalancerController) getUpstreamServers(ngxCfg nginx.NginxConfigur
 				continue
 			}
 
+			rl, err := ratelimit.ParseAnnotations(ing)
+			glog.V(3).Infof("nginx rate limit %v", rl)
+			if err != nil {
+				glog.V(3).Infof("error reading rate limit annotation in Ingress %v/%v: %v", ing.GetNamespace(), ing.GetName(), err)
+			}
+
 			host := rule.Host
 			if host == "" {
 				host = defServerName
@@ -615,6 +622,7 @@ func (lbc *loadBalancerController) getUpstreamServers(ngxCfg nginx.NginxConfigur
 							glog.V(3).Infof("error parsing rewrite annotations for Ingress rule %v/%v: %v", ing.GetNamespace(), ing.GetName(), err)
 						}
 						loc.Redirect = *locRew
+						loc.RateLimit = *rl
 
 						addLoc = false
 						continue
@@ -635,9 +643,10 @@ func (lbc *loadBalancerController) getUpstreamServers(ngxCfg nginx.NginxConfigur
 					}
 
 					server.Locations = append(server.Locations, &nginx.Location{
-						Path:     nginxPath,
-						Upstream: *ups,
-						Redirect: *locRew,
+						Path:      nginxPath,
+						Upstream:  *ups,
+						Redirect:  *locRew,
+						RateLimit: *rl,
 					})
 				}
 			}

ingress/controllers/nginx/nginx.tmpl

@@ -156,6 +156,12 @@ http {
     }
     {{ end }}
 
+    {{/* build all the required rate limit zones. Each annotation requires a dedicated zone */}}
+    {{/* 1MB -> 16 thousand 64-byte states or about 8 thousand 128-byte states */}}
+    {{ $zone := range (buildRateLimitZones .servers) }}
+    {{ $zone }}
+    {{ end }}
+
     {{ range $server := .servers }}
     server {
         server_name {{ $server.Name }};
@@ -180,7 +186,10 @@ http {
         {{- range $location := $server.Locations }}
         {{- $path := buildLocation $location }}
         location {{ $path }} {
-        location {{ $path }} {        
+            {{/* if the location contains a rate limit annotation, create one */}}
+            {{ $limits := buildRateLimit $location }}
+            {{- range $limit := $limits }}
+            {{ $limit }}{{ end }}
             proxy_set_header Host                   $host;
 
             # Pass Real IP

ingress/controllers/nginx/nginx/nginx.go

@@ -17,6 +17,7 @@ limitations under the License.
 package nginx
 
 import (
+	"k8s.io/contrib/ingress/controllers/nginx/nginx/ratelimit"
 	"k8s.io/contrib/ingress/controllers/nginx/nginx/rewrite"
 )
 
@@ -93,6 +94,7 @@ type Location struct {
 	IsDefBackend bool
 	Upstream     Upstream
 	Redirect     rewrite.Redirect
+	RateLimit    ratelimit.RateLimit
 }
 
 // LocationByPath sorts location by path

ingress/controllers/nginx/nginx/ratelimit/main.go

@@ -0,0 +1,126 @@
+/*
+Copyright 2016 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package ratelimit
+
+import (
+	"errors"
+	"fmt"
+	"strconv"
+
+	"k8s.io/kubernetes/pkg/apis/extensions"
+)
+
+const (
+	limitIp  = "ingress.kubernetes.io/limit-connections"
+	limitRps = "ingress.kubernetes.io/limit-rps"
+
+	// allow 5 times the specified limit as burst
+	defBurst = 5
+
+	// 1MB -> 16 thousand 64-byte states or about 8 thousand 128-byte states
+	// default is 5MB
+	defSharedSize = 5
+)
+
+var (
+	// ErrInvalidRateLimit is returned when the annotation caontains invalid values
+	ErrInvalidRateLimit = errors.New("invalid rate limit value. Must be > 0")
+
+	// ErrMissingAnnotations is returned when the ingress rule
+	// does not contains annotations related with rate limit
+	ErrMissingAnnotations = errors.New("no annotations present")
+)
+
+// RateLimit returns rate limit configuration for an Ingress rule
+// Is possible to limit the number of connections per IP address or
+// connections per second.
+// Note: Is possible to specify both limits
+type RateLimit struct {
+	// Connections indicates a limit with the number of connections per IP address
+	Connections Zone
+	// RPS indicates a limit with the number of connections per second
+	RPS Zone
+}
+
+// Zone returns information about the NGINX rate limit (limit_req_zone)
+// http://nginx.org/en/docs/http/ngx_http_limit_req_module.html#limit_req_zone
+type Zone struct {
+	Name  string
+	Limit int
+	Burst int
+	// SharedSize amount of shared memory for the zone
+	SharedSize int
+}
+
+type ingAnnotations map[string]string
+
+func (a ingAnnotations) limitIp() int {
+	val, ok := a[limitIp]
+	if ok {
+		if i, err := strconv.Atoi(val); err == nil {
+			return i
+		}
+	}
+
+	return 0
+}
+
+func (a ingAnnotations) limitRps() int {
+	val, ok := a[limitRps]
+	if ok {
+		if i, err := strconv.Atoi(val); err == nil {
+			return i
+		}
+	}
+
+	return 0
+}
+
+// ParseAnnotations parses the annotations contained in the ingress
+// rule used to rewrite the defined paths
+func ParseAnnotations(ing *extensions.Ingress) (*RateLimit, error) {
+	if ing.GetAnnotations() == nil {
+		return &RateLimit{}, ErrMissingAnnotations
+	}
+
+	rps := ingAnnotations(ing.GetAnnotations()).limitRps()
+	conn := ingAnnotations(ing.GetAnnotations()).limitIp()
+
+	if rps == 0 && conn == 0 {
+		return &RateLimit{
+			Connections: Zone{},
+			RPS:         Zone{},
+		}, ErrInvalidRateLimit
+	}
+
+	zoneName := fmt.Sprintf("%v_%v", ing.GetNamespace(), ing.GetName())
+
+	return &RateLimit{
+		Connections: Zone{
+			Name:       fmt.Sprintf("%v_conn", zoneName),
+			Limit:      conn,
+			Burst:      conn * defBurst,
+			SharedSize: defSharedSize,
+		},
+		RPS: Zone{
+			Name:       fmt.Sprintf("%v_rps", zoneName),
+			Limit:      rps,
+			Burst:      conn * defBurst,
+			SharedSize: defSharedSize,
+		},
+	}, nil
+}

ingress/controllers/nginx/nginx/ratelimit/main_test.go

@@ -0,0 +1,129 @@
+/*
+Copyright 2015 The Kubernetes Authors All rights reserved.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package ratelimit
+
+import (
+	"testing"
+
+	"k8s.io/kubernetes/pkg/api"
+	"k8s.io/kubernetes/pkg/apis/extensions"
+	"k8s.io/kubernetes/pkg/util/intstr"
+)
+
+func buildIngress() *extensions.Ingress {
+	defaultBackend := extensions.IngressBackend{
+		ServiceName: "default-backend",
+		ServicePort: intstr.FromInt(80),
+	}
+
+	return &extensions.Ingress{
+		ObjectMeta: api.ObjectMeta{
+			Name:      "foo",
+			Namespace: api.NamespaceDefault,
+		},
+		Spec: extensions.IngressSpec{
+			Backend: &extensions.IngressBackend{
+				ServiceName: "default-backend",
+				ServicePort: intstr.FromInt(80),
+			},
+			Rules: []extensions.IngressRule{
+				{
+					Host: "foo.bar.com",
+					IngressRuleValue: extensions.IngressRuleValue{
+						HTTP: &extensions.HTTPIngressRuleValue{
+							Paths: []extensions.HTTPIngressPath{
+								{
+									Path:    "/foo",
+									Backend: defaultBackend,
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+}
+
+func TestAnnotations(t *testing.T) {
+	ing := buildIngress()
+
+	lip := ingAnnotations(ing.GetAnnotations()).limitIp()
+	if lip != 0 {
+		t.Error("Expected 0 in limit by ip but %v was returned", lip)
+	}
+
+	lrps := ingAnnotations(ing.GetAnnotations()).limitRps()
+	if lrps != 0 {
+		t.Error("Expected 0 in limit by rps but %v was returend", lrps)
+	}
+
+	data := map[string]string{}
+	data[limitIp] = "5"
+	data[limitRps] = "100"
+	ing.SetAnnotations(data)
+
+	lip = ingAnnotations(ing.GetAnnotations()).limitIp()
+	if lip != 5 {
+		t.Error("Expected %v in limit by ip but %v was returend", lip)
+	}
+
+	lrps = ingAnnotations(ing.GetAnnotations()).limitRps()
+	if lrps != 100 {
+		t.Error("Expected 100 in limit by rps but %v was returend", lrps)
+	}
+}
+
+func TestWithoutAnnotations(t *testing.T) {
+	ing := buildIngress()
+	_, err := ParseAnnotations(ing)
+	if err == nil {
+		t.Error("Expected error with ingress without annotations")
+	}
+}
+
+func TestBadRateLimiting(t *testing.T) {
+	ing := buildIngress()
+
+	data := map[string]string{}
+	data[limitIp] = "0"
+	data[limitRps] = "0"
+	ing.SetAnnotations(data)
+
+	_, err := ParseAnnotations(ing)
+	if err == nil {
+		t.Errorf("Expected error with invalid limits (0)")
+	}
+
+	data = map[string]string{}
+	data[limitIp] = "5"
+	data[limitRps] = "100"
+	ing.SetAnnotations(data)
+
+	rateLimit, err := ParseAnnotations(ing)
+	if err != nil {
+		t.Errorf("Uxpected error: %v", err)
+	}
+
+	if rateLimit.Connections.Limit != 5 {
+		t.Error("Expected 5 in limit by ip but %v was returend", rateLimit.Connections)
+	}
+
+	if rateLimit.RPS.Limit != 100 {
+		t.Error("Expected 100 in limit by rps but %v was returend", rateLimit.RPS)
+	}
+}