Merge pull request #148 from rramkumar1/rate-limit

Initial implementation for ingress rate limiting

cmd/glbc/app/clients.go

@@ -36,6 +36,7 @@ import (
 	_ "k8s.io/client-go/plugin/pkg/client/auth/gcp"
 
 	"k8s.io/ingress-gce/pkg/flags"
+	"k8s.io/ingress-gce/pkg/ratelimit"
 	"k8s.io/ingress-gce/pkg/utils"
 )
 
@@ -95,6 +96,12 @@ func NewGCEClient() *gce.GCECloud {
 		provider, err := cloudprovider.GetCloudProvider("gce", configReader())
 		if err == nil {
 			cloud := provider.(*gce.GCECloud)
+			// Configure GCE rate limiting
+			rl, err := ratelimit.NewGCERateLimiter(flags.F.GCERateLimit.Values())
+			if err != nil {
+				glog.Fatalf("Error configuring rate limiting: %v", err)
+			}
+			cloud.SetRateLimiter(rl)
 			// If this controller is scheduled on a node without compute/rw
 			// it won't be allowed to list backends. We can assume that the
 			// user has no need for Ingress in this case. If they grant

pkg/flags/flags.go

@@ -43,6 +43,7 @@ var (
 		ConfigFilePath  string
 		DefaultSvc      string
 		DeleteAllOnQuit bool
+		GCERateLimit    RateLimitSpecs
 		HealthCheckPath string
 		HealthzPort     int
 		InCluster       bool
@@ -58,6 +59,7 @@ var (
 
 func init() {
 	F.NodePortRanges.ports = []string{DefaultNodePortRange}
+	F.GCERateLimit.specs = []string{"alpha.Operations.Get,qps,10,100", "beta.Operations.Get,qps,10,100", "ga.Operations.Get,qps,10,100"}
 }
 
 // Register flags with the command line parser.
@@ -85,6 +87,15 @@ the default backend.`)
 external cloud resources as it's shutting down. Mostly used for testing. In
 normal environments the controller should only delete a loadbalancer if the
 associated Ingress is deleted.`)
+	flag.Var(&F.GCERateLimit, "gce-ratelimit",
+		`Optional, can be used to rate limit certain GCE API calls. Example usage:
+--gce-ratelimit=ga.Addresses.Get,qps,1.5,5
+(limit ga.Addresses.Get to maximum of 1.5 qps with a burst of 5).
+Use the flag more than once to rate limit more than one call. If you do not
+specify this flag, the default is to rate limit Operations.Get for all versions.
+If you do specify this flag one or more times, this default will be overwritten.
+If you want to still use the default, simply specify it along with your other
+values.`)
 	flag.StringVar(&F.HealthCheckPath, "health-check-path", "/",
 		`Path used to health-check a backend service. All Services must serve a
 200 page on this path. Currently this is only configurable globally.`)
@@ -113,6 +124,32 @@ L7 load balancing. CSV values accepted. Example: -node-port-ranges=80,8080,400-5
 		`This flag has been deprecated and no longer has any effect.`)
 }
 
+type RateLimitSpecs struct {
+	specs []string
+	isSet bool
+}
+
+// Part of the flag.Value interface.
+func (r *RateLimitSpecs) String() string {
+	return strings.Join(r.specs, ";")
+}
+
+// Set supports the flag being repeated multiple times. Part of the flag.Value interface.
+func (r *RateLimitSpecs) Set(value string) error {
+	// On first Set(), clear the original defaults
+	// On subsequent Set()'s, append.
+	if !r.isSet {
+		r.specs = []string{}
+		r.isSet = true
+	}
+	r.specs = append(r.specs, value)
+	return nil
+}
+
+func (r *RateLimitSpecs) Values() []string {
+	return r.specs
+}
+
 type PortRanges struct {
 	ports []string
 	isSet bool

pkg/ratelimit/ratelimit.go

@@ -0,0 +1,144 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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 (
+	"context"
+	"fmt"
+	"strconv"
+	"strings"
+
+	"github.com/golang/glog"
+	"k8s.io/client-go/util/flowcontrol"
+	"k8s.io/kubernetes/pkg/cloudprovider/providers/gce/cloud"
+	"k8s.io/kubernetes/pkg/cloudprovider/providers/gce/cloud/meta"
+)
+
+// GCERateLimiter implements cloud.RateLimiter
+type GCERateLimiter struct {
+	// Map a RateLimitKey to its rate limiter implementation.
+	rateLimitImpls map[cloud.RateLimitKey]flowcontrol.RateLimiter
+}
+
+// NewGCERateLimiter parses the list of rate limiting specs passed in and
+// returns a properly configured cloud.RateLimiter implementation.
+// Expected format of specs: {"[version].[service].[operation],[type],[param1],[param2],..", "..."}
+func NewGCERateLimiter(specs []string) (*GCERateLimiter, error) {
+	rateLimitImpls := make(map[cloud.RateLimitKey]flowcontrol.RateLimiter)
+	// Within each specification, split on comma to get the operation,
+	// rate limiter type, and extra parameters.
+	for _, spec := range specs {
+		params := strings.Split(spec, ",")
+		if len(params) < 2 {
+			return nil, fmt.Errorf("Must at least specify operation and rate limiter type.")
+		}
+		// params[0] should consist of the operation to rate limit.
+		key, err := constructRateLimitKey(params[0])
+		if err != nil {
+			return nil, err
+		}
+		// params[1:] should consist of the rate limiter type and extra params.
+		impl, err := constructRateLimitImpl(params[1:])
+		if err != nil {
+			return nil, err
+		}
+		rateLimitImpls[key] = impl
+		glog.Infof("Configured rate limiting for: %v", key)
+	}
+	if len(rateLimitImpls) == 0 {
+		return nil, nil
+	}
+	return &GCERateLimiter{rateLimitImpls}, nil
+}
+
+// Implementation of cloud.RateLimiter
+func (l *GCERateLimiter) Accept(ctx context.Context, key *cloud.RateLimitKey) error {
+	ch := make(chan struct{})
+	go func() {
+		// Call flowcontrol.RateLimiter implementation.
+		impl := l.rateLimitImpl(key)
+		if impl != nil {
+			impl.Accept()
+		}
+		close(ch)
+	}()
+	select {
+	case <-ch:
+		break
+	case <-ctx.Done():
+		return ctx.Err()
+	}
+	return nil
+}
+
+// rateLimitImpl returns the flowcontrol.RateLimiter implementation
+// associated with the passed in key.
+func (l *GCERateLimiter) rateLimitImpl(key *cloud.RateLimitKey) flowcontrol.RateLimiter {
+	// Since the passed in key will have the ProjectID field filled in, we need to
+	// create a copy which does not, so that retreiving the rate limiter implementation
+	// through the map works as expected.
+	keyCopy := cloud.RateLimitKey{
+		ProjectID: "",
+		Operation: key.Operation,
+		Version:   key.Version,
+		Service:   key.Service,
+	}
+	return l.rateLimitImpls[keyCopy]
+}
+
+// Expected format of param is [version].[service].[operation]
+func constructRateLimitKey(param string) (cloud.RateLimitKey, error) {
+	var retVal cloud.RateLimitKey
+	params := strings.Split(param, ".")
+	if len(params) != 3 {
+		return retVal, fmt.Errorf("Must specify rate limit in [version].[service].[operation] format: %v", param)
+	}
+	// TODO(rramkumar): Add another layer of validation here?
+	version := meta.Version(params[0])
+	service := params[1]
+	operation := params[2]
+	retVal = cloud.RateLimitKey{
+		ProjectID: "",
+		Operation: operation,
+		Version:   version,
+		Service:   service,
+	}
+	return retVal, nil
+}
+
+// constructRateLimitImpl parses the slice and returns a flowcontrol.RateLimiter
+// Expected format is [type],[param1],[param2],...
+func constructRateLimitImpl(params []string) (flowcontrol.RateLimiter, error) {
+	// For now, only the "qps" type is supported.
+	rlType := params[0]
+	implArgs := params[1:]
+	if rlType == "qps" {
+		if len(implArgs) != 2 {
+			return nil, fmt.Errorf("Invalid number of args for rate limiter type %v. Expected %d, Got %v", rlType, 2, len(implArgs))
+		}
+		qps, err := strconv.ParseFloat(implArgs[0], 32)
+		if err != nil || qps <= 0 {
+			return nil, fmt.Errorf("Invalid argument for rate limiter type %v. Either %v is not a float or not greater than 0.", rlType, implArgs[0])
+		}
+		burst, err := strconv.Atoi(implArgs[1])
+		if err != nil {
+			return nil, fmt.Errorf("Invalid argument for rate limiter type %v. Expected %v to be a int.", rlType, implArgs[1])
+		}
+		return flowcontrol.NewTokenBucketRateLimiter(float32(qps), burst), nil
+	}
+	return nil, fmt.Errorf("Invalid rate limiter type provided: %v", rlType)
+}

pkg/ratelimit/ratelimit_test.go

@@ -0,0 +1,56 @@
+/*
+Copyright 2018 The Kubernetes Authors.
+
+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"
+)
+
+func TestConfigureGCERateLimiting(t *testing.T) {
+	validTestCases := [][]string{
+		[]string{"ga.Addresses.Get,qps,1.5,5"},
+		[]string{"ga.Addresses.List,qps,2,10"},
+		[]string{"ga.Addresses.Get,qps,1.5,5", "ga.Firewalls.Get,qps,1.5,5"},
+		[]string{"ga.Operations.Get,qps,10,100"},
+	}
+	invalidTestCases := [][]string{
+		[]string{"gaAddresses.Get,qps,1.5,5"},
+		[]string{"gaAddresses.Get,qps,0,5"},
+		[]string{"gaAddresses.Get,qps,-1,5"},
+		[]string{"ga.Addresses.Get,qps,1.5.5"},
+		[]string{"gaAddresses.Get,qps,1.5,5.5"},
+		[]string{"gaAddressesGet,qps,1.5,5.5"},
+		[]string{"gaAddressesGet,qps,1.5"},
+		[]string{"ga.Addresses.Get,foo,1.5,5"},
+		[]string{"ga.Addresses.Get,1.5,5"},
+		[]string{"ga.Addresses.Get,qps,1.5,5", "gaFirewalls.Get,qps,1.5,5"},
+	}
+
+	for _, testCase := range validTestCases {
+		_, err := NewGCERateLimiter(testCase)
+		if err != nil {
+			t.Errorf("Did not expect an error for test case: %v", testCase)
+		}
+	}
+
+	for _, testCase := range invalidTestCases {
+		_, err := NewGCERateLimiter(testCase)
+		if err == nil {
+			t.Errorf("Expected an error for test case: %v", testCase)
+		}
+	}
+}