mpagenko | af80163 | 2020-07-03 10:00:42 +0000 | [diff] [blame] | 1 | // Copyright (c) 2017 Uber Technologies, Inc. |
| 2 | // |
| 3 | // Licensed under the Apache License, Version 2.0 (the "License"); |
| 4 | // you may not use this file except in compliance with the License. |
| 5 | // You may obtain a copy of the License at |
| 6 | // |
| 7 | // http://www.apache.org/licenses/LICENSE-2.0 |
| 8 | // |
| 9 | // Unless required by applicable law or agreed to in writing, software |
| 10 | // distributed under the License is distributed on an "AS IS" BASIS, |
| 11 | // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| 12 | // See the License for the specific language governing permissions and |
| 13 | // limitations under the License. |
| 14 | |
| 15 | package remote |
| 16 | |
| 17 | import ( |
| 18 | "fmt" |
| 19 | "net/url" |
| 20 | "sync" |
| 21 | "time" |
| 22 | |
| 23 | "github.com/uber/jaeger-client-go/internal/baggage" |
| 24 | thrift "github.com/uber/jaeger-client-go/thrift-gen/baggage" |
| 25 | "github.com/uber/jaeger-client-go/utils" |
| 26 | ) |
| 27 | |
| 28 | type httpBaggageRestrictionManagerProxy struct { |
| 29 | url string |
| 30 | } |
| 31 | |
| 32 | func newHTTPBaggageRestrictionManagerProxy(hostPort, serviceName string) *httpBaggageRestrictionManagerProxy { |
| 33 | v := url.Values{} |
| 34 | v.Set("service", serviceName) |
| 35 | return &httpBaggageRestrictionManagerProxy{ |
| 36 | url: fmt.Sprintf("http://%s/baggageRestrictions?%s", hostPort, v.Encode()), |
| 37 | } |
| 38 | } |
| 39 | |
| 40 | func (s *httpBaggageRestrictionManagerProxy) GetBaggageRestrictions(serviceName string) ([]*thrift.BaggageRestriction, error) { |
| 41 | var out []*thrift.BaggageRestriction |
| 42 | if err := utils.GetJSON(s.url, &out); err != nil { |
| 43 | return nil, err |
| 44 | } |
| 45 | return out, nil |
| 46 | } |
| 47 | |
| 48 | // RestrictionManager manages baggage restrictions by retrieving baggage restrictions from agent |
| 49 | type RestrictionManager struct { |
| 50 | options |
| 51 | |
| 52 | mux sync.RWMutex |
| 53 | serviceName string |
| 54 | restrictions map[string]*baggage.Restriction |
| 55 | thriftProxy thrift.BaggageRestrictionManager |
| 56 | pollStopped sync.WaitGroup |
| 57 | stopPoll chan struct{} |
| 58 | invalidRestriction *baggage.Restriction |
| 59 | validRestriction *baggage.Restriction |
| 60 | |
| 61 | // Determines if the manager has successfully retrieved baggage restrictions from agent |
| 62 | initialized bool |
| 63 | } |
| 64 | |
| 65 | // NewRestrictionManager returns a BaggageRestrictionManager that polls the agent for the latest |
| 66 | // baggage restrictions. |
| 67 | func NewRestrictionManager(serviceName string, options ...Option) *RestrictionManager { |
| 68 | // TODO there is a developing use case where a single tracer can generate traces on behalf of many services. |
| 69 | // restrictionsMap will need to exist per service |
| 70 | opts := applyOptions(options...) |
| 71 | m := &RestrictionManager{ |
| 72 | serviceName: serviceName, |
| 73 | options: opts, |
| 74 | restrictions: make(map[string]*baggage.Restriction), |
| 75 | thriftProxy: newHTTPBaggageRestrictionManagerProxy(opts.hostPort, serviceName), |
| 76 | stopPoll: make(chan struct{}), |
| 77 | invalidRestriction: baggage.NewRestriction(false, 0), |
| 78 | validRestriction: baggage.NewRestriction(true, defaultMaxValueLength), |
| 79 | } |
| 80 | m.pollStopped.Add(1) |
| 81 | go m.pollManager() |
| 82 | return m |
| 83 | } |
| 84 | |
| 85 | // isReady returns true if the manager has retrieved baggage restrictions from the remote source. |
| 86 | func (m *RestrictionManager) isReady() bool { |
| 87 | m.mux.RLock() |
| 88 | defer m.mux.RUnlock() |
| 89 | return m.initialized |
| 90 | } |
| 91 | |
| 92 | // GetRestriction implements RestrictionManager#GetRestriction. |
| 93 | func (m *RestrictionManager) GetRestriction(service, key string) *baggage.Restriction { |
| 94 | m.mux.RLock() |
| 95 | defer m.mux.RUnlock() |
| 96 | if !m.initialized { |
| 97 | if m.denyBaggageOnInitializationFailure { |
| 98 | return m.invalidRestriction |
| 99 | } |
| 100 | return m.validRestriction |
| 101 | } |
| 102 | if restriction, ok := m.restrictions[key]; ok { |
| 103 | return restriction |
| 104 | } |
| 105 | return m.invalidRestriction |
| 106 | } |
| 107 | |
| 108 | // Close stops remote polling and closes the RemoteRestrictionManager. |
| 109 | func (m *RestrictionManager) Close() error { |
| 110 | close(m.stopPoll) |
| 111 | m.pollStopped.Wait() |
| 112 | return nil |
| 113 | } |
| 114 | |
| 115 | func (m *RestrictionManager) pollManager() { |
| 116 | defer m.pollStopped.Done() |
| 117 | // attempt to initialize baggage restrictions |
| 118 | if err := m.updateRestrictions(); err != nil { |
| 119 | m.logger.Error(fmt.Sprintf("Failed to initialize baggage restrictions: %s", err.Error())) |
| 120 | } |
| 121 | ticker := time.NewTicker(m.refreshInterval) |
| 122 | defer ticker.Stop() |
| 123 | |
| 124 | for { |
| 125 | select { |
| 126 | case <-ticker.C: |
| 127 | if err := m.updateRestrictions(); err != nil { |
| 128 | m.logger.Error(fmt.Sprintf("Failed to update baggage restrictions: %s", err.Error())) |
| 129 | } |
| 130 | case <-m.stopPoll: |
| 131 | return |
| 132 | } |
| 133 | } |
| 134 | } |
| 135 | |
| 136 | func (m *RestrictionManager) updateRestrictions() error { |
| 137 | restrictions, err := m.thriftProxy.GetBaggageRestrictions(m.serviceName) |
| 138 | if err != nil { |
| 139 | m.metrics.BaggageRestrictionsUpdateFailure.Inc(1) |
| 140 | return err |
| 141 | } |
| 142 | newRestrictions := m.parseRestrictions(restrictions) |
| 143 | m.metrics.BaggageRestrictionsUpdateSuccess.Inc(1) |
| 144 | m.mux.Lock() |
| 145 | defer m.mux.Unlock() |
| 146 | m.initialized = true |
| 147 | m.restrictions = newRestrictions |
| 148 | return nil |
| 149 | } |
| 150 | |
| 151 | func (m *RestrictionManager) parseRestrictions(restrictions []*thrift.BaggageRestriction) map[string]*baggage.Restriction { |
| 152 | setters := make(map[string]*baggage.Restriction, len(restrictions)) |
| 153 | for _, restriction := range restrictions { |
| 154 | setters[restriction.BaggageKey] = baggage.NewRestriction(true, int(restriction.MaxValueLength)) |
| 155 | } |
| 156 | return setters |
| 157 | } |