99 lines
2.7 KiB
Go
99 lines
2.7 KiB
Go
/*
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Copyright 2016 The Kubernetes Authors.
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Licensed under the Apache License, Version 2.0 (the "License");
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you may not use this file except in compliance with the License.
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You may obtain a copy of the License at
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http://www.apache.org/licenses/LICENSE-2.0
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Unless required by applicable law or agreed to in writing, software
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distributed under the License is distributed on an "AS IS" BASIS,
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WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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See the License for the specific language governing permissions and
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limitations under the License.
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*/
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package ratelimit
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import (
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"errors"
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"fmt"
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"k8s.io/ingress/core/pkg/ingress/annotations/parser"
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"k8s.io/kubernetes/pkg/apis/extensions"
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)
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const (
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limitIP = "ingress.kubernetes.io/limit-connections"
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limitRPS = "ingress.kubernetes.io/limit-rps"
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// allow 5 times the specified limit as burst
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defBurst = 5
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// 1MB -> 16 thousand 64-byte states or about 8 thousand 128-byte states
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// default is 5MB
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defSharedSize = 5
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)
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var (
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// ErrInvalidRateLimit is returned when the annotation caontains invalid values
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ErrInvalidRateLimit = errors.New("invalid rate limit value. Must be > 0")
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)
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// RateLimit returns rate limit configuration for an Ingress rule
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// Is possible to limit the number of connections per IP address or
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// connections per second.
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// Note: Is possible to specify both limits
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type RateLimit struct {
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// Connections indicates a limit with the number of connections per IP address
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Connections Zone
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// RPS indicates a limit with the number of connections per second
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RPS Zone
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}
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// Zone returns information about the NGINX rate limit (limit_req_zone)
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// http://nginx.org/en/docs/http/ngx_http_limit_req_module.html#limit_req_zone
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type Zone struct {
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Name string
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Limit int
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Burst int
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// SharedSize amount of shared memory for the zone
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SharedSize int
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}
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// ParseAnnotations parses the annotations contained in the ingress
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// rule used to rewrite the defined paths
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func ParseAnnotations(ing *extensions.Ingress) (*RateLimit, error) {
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if ing.GetAnnotations() == nil {
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return &RateLimit{}, parser.ErrMissingAnnotations
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}
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rps, _ := parser.GetIntAnnotation(limitRPS, ing)
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conn, _ := parser.GetIntAnnotation(limitIP, ing)
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if rps == 0 && conn == 0 {
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return &RateLimit{
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Connections: Zone{},
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RPS: Zone{},
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}, ErrInvalidRateLimit
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}
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zoneName := fmt.Sprintf("%v_%v", ing.GetNamespace(), ing.GetName())
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return &RateLimit{
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Connections: Zone{
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Name: fmt.Sprintf("%v_conn", zoneName),
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Limit: conn,
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Burst: conn * defBurst,
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SharedSize: defSharedSize,
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},
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RPS: Zone{
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Name: fmt.Sprintf("%v_rps", zoneName),
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Limit: rps,
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Burst: conn * defBurst,
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SharedSize: defSharedSize,
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},
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}, nil
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}
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