| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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 circuitbreaker |
| |
| import ( |
| "fmt" |
| stdHttp "net/http" |
| "strings" |
| ) |
| |
| import ( |
| sentinel "github.com/alibaba/sentinel-golang/api" |
| "github.com/alibaba/sentinel-golang/core/circuitbreaker" |
| sc "github.com/alibaba/sentinel-golang/core/config" |
| ) |
| |
| import ( |
| "github.com/apache/dubbo-go-pixiu/pixiu/pkg/common/constant" |
| "github.com/apache/dubbo-go-pixiu/pixiu/pkg/common/extension/filter" |
| "github.com/apache/dubbo-go-pixiu/pixiu/pkg/context/http" |
| pkgs "github.com/apache/dubbo-go-pixiu/pixiu/pkg/filter/sentinel" |
| "github.com/apache/dubbo-go-pixiu/pixiu/pkg/logger" |
| ) |
| |
| const ( |
| Kind = constant.HTTPCircuitBreakerFilter |
| Segmentation = "@" |
| ) |
| |
| func init() { |
| filter.RegisterHttpFilter(&Plugin{}) |
| } |
| |
| type ( |
| // Plugin is http filter plugin. |
| Plugin struct { |
| } |
| |
| // FilterFactory is http filter instance |
| FilterFactory struct { |
| cfg *Config |
| matcher *pkgs.Matcher |
| } |
| |
| // Filter is http filter instance |
| Filter struct { |
| cfg *Config |
| matcher *pkgs.Matcher |
| } |
| |
| // Config describe the config of FilterFactory |
| Config struct { |
| Resources []*pkgs.Resource `json:"resources,omitempty" yaml:"resources,omitempty"` |
| Rules []*circuitbreaker.Rule `json:"rules" yaml:"rules"` // circuit breaker base config info |
| } |
| ) |
| |
| func (p *Plugin) Kind() string { |
| return Kind |
| } |
| |
| func (p *Plugin) CreateFilterFactory() (filter.HttpFilterFactory, error) { |
| return &FilterFactory{cfg: &Config{}}, nil |
| } |
| |
| func (factory *FilterFactory) PrepareFilterChain(ctx *http.HttpContext, chain filter.FilterChain) error { |
| chain.AppendDecodeFilters(&Filter{cfg: factory.cfg, matcher: factory.matcher}) |
| return nil |
| } |
| |
| func (f *Filter) Decode(ctx *http.HttpContext) filter.FilterStatus { |
| |
| url := ctx.GetUrl() |
| resourceName, ok := f.matcher.Match(url) |
| |
| if !ok { |
| return filter.Continue |
| } |
| |
| // entry, blockErr := sentinel.Entry(resourceName, sentinel.WithResourceType(base.ResTypeAPIGateway), sentinel.WithTrafficType(base.Inbound)) |
| entry, blockErr := sentinel.Entry(resourceName) |
| |
| // if blockErr not nil, indicates the request was blocked by Sentinel |
| if blockErr != nil { |
| ctx.SendLocalReply(stdHttp.StatusServiceUnavailable, constant.Default503Body) |
| return filter.Stop |
| } |
| defer entry.Exit() |
| return filter.Continue |
| } |
| |
| func (factory *FilterFactory) Config() interface{} { |
| return factory.cfg |
| } |
| |
| func (factory *FilterFactory) Apply() error { |
| if len(factory.cfg.Rules) == 0 || len(factory.cfg.Resources) == 0 { |
| return fmt.Errorf("circuit breaker router or resources is null") |
| } |
| |
| factory.resetResources() |
| |
| // init matcher |
| factory.matcher = pkgs.NewMatcher() |
| factory.matcher.Load(factory.cfg.Resources) |
| |
| resourcesMap := make(map[string]circuitbreaker.Rule, len(factory.cfg.Rules)) |
| for _, rule := range factory.cfg.Rules { |
| resourcesMap[rule.Resource] = *rule |
| } |
| |
| rules := make([]*circuitbreaker.Rule, 0, len(factory.cfg.Rules)) |
| for _, rule := range factory.cfg.Resources { |
| c, ok := resourcesMap[strings.Split(rule.Name, Segmentation)[0]] |
| if !ok { |
| logger.Warn("circuit breaker resource does not exist") |
| continue |
| } |
| |
| c.Resource = rule.Name |
| rules = append(rules, &c) |
| } |
| |
| return loadRules(rules) |
| } |
| |
| func (factory *FilterFactory) resetResources() { |
| resources := make([]*pkgs.Resource, 0, len(factory.cfg.Resources)) |
| |
| for _, rule := range factory.cfg.Resources { |
| for _, item := range rule.Items { |
| resources = append(resources, &pkgs.Resource{Name: rule.Name + Segmentation + item.Pattern, Items: []*pkgs.Item{item}}) |
| } |
| } |
| factory.cfg.Resources = resources |
| } |
| |
| func loadRules(rules []*circuitbreaker.Rule) error { |
| conf := sc.NewDefaultConfig() |
| conf.Sentinel.Log.Logger = pkgs.GetWrappedLogger() |
| err := sentinel.InitWithConfig(conf) |
| if err != nil { |
| logger.Error("circuit breaker init fail ", err) |
| return err |
| } |
| |
| if _, err = circuitbreaker.LoadRules(rules); err != nil { |
| logger.Error("circuit breaker load rules fail ", err) |
| return err |
| } |
| return nil |
| } |