pkg/xapp/xapp.go

   1 /*
   2 ==================================================================================
   3   Copyright (c) 2019 AT&T Intellectual Property.
   4   Copyright (c) 2019 Nokia
   5
   6    Licensed under the Apache License, Version 2.0 (the "License");
   7    you may not use this file except in compliance with the License.
   8    You may obtain a copy of the License at
   9
  10        http://www.apache.org/licenses/LICENSE-2.0
  11
  12    Unless required by applicable law or agreed to in writing, software
  13    distributed under the License is distributed on an "AS IS" BASIS,
  14    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  15    See the License for the specific language governing permissions and
  16    limitations under the License.
  17 ==================================================================================
  18 */
  19
  20 package xapp
  21
  22 import (
  23         "fmt"
  24         "github.com/spf13/viper"
  25         "net/http"
  26         "os"
  27         "os/signal"
  28         "sync/atomic"
  29         "syscall"
  30         "time"
  31 )
  32
  33 type ReadyCB func(interface{})
  34 type ShutdownCB func()
  35
  36 var (
  37         // XApp is an application instance
  38         Rmr           *RMRClient
  39         Sdl           *SDLClient
  40         Rnib          *RNIBClient
  41         Resource      *Router
  42         Metric        *Metrics
  43         Logger        *Log
  44         Config        Configurator
  45         Subscription  *Subscriber
  46         Alarm         *AlarmClient
  47         readyCb       ReadyCB
  48         readyCbParams interface{}
  49         shutdownCb    ShutdownCB
  50         shutdownFlag  int32
  51         shutdownCnt   int32
  52 )
  53
  54 func IsReady() bool {
  55         return Rmr != nil && Rmr.IsReady() && Sdl != nil && Sdl.IsReady()
  56 }
  57
  58 func SetReadyCB(cb ReadyCB, params interface{}) {
  59         readyCb = cb
  60         readyCbParams = params
  61 }
  62
  63 func XappReadyCb(params interface{}) {
  64         Alarm = NewAlarmClient(viper.GetString("moId"), viper.GetString("name"))
  65         if readyCb != nil {
  66                 readyCb(readyCbParams)
  67         }
  68 }
  69
  70 func SetShutdownCB(cb ShutdownCB) {
  71         shutdownCb = cb
  72 }
  73
  74 func InstallSignalHandler() {
  75         //
  76         // Signal handlers to really exit program.
  77         // shutdownCb can hang until application has
  78         // made all needed gracefull shutdown actions
  79         // hardcoded limit for shutdown is 20 seconds
  80         //
  81         interrupt := make(chan os.Signal, 1)
  82         signal.Notify(interrupt, syscall.SIGINT, syscall.SIGTERM)
  83         //signal handler function
  84         go func() {
  85                 for range interrupt {
  86                         if atomic.CompareAndSwapInt32(&shutdownFlag, 0, 1) {
  87                                 // close function
  88                                 go func() {
  89                                         timeout := int(20)
  90                                         sentry := make(chan struct{})
  91                                         defer close(sentry)
  92
  93                                         // close callback
  94                                         go func() {
  95                                                 if shutdownCb != nil {
  96                                                         shutdownCb()
  97                                                 }
  98                                                 sentry <- struct{}{}
  99                                         }()
 100                                         select {
 101                                         case <-time.After(time.Duration(timeout) * time.Second):
 102                                                 Logger.Info("xapp-frame shutdown callback took more than %d seconds", timeout)
 103                                         case <-sentry:
 104                                                 Logger.Info("xapp-frame shutdown callback handled within %d seconds", timeout)
 105                                         }
 106                                         os.Exit(0)
 107                                 }()
 108                         } else {
 109                                 newCnt := atomic.AddInt32(&shutdownCnt, 1)
 110                                 Logger.Info("xapp-frame shutdown already ongoing. Forced exit counter %d/%d ", newCnt, 5)
 111                                 if newCnt >= 5 {
 112                                         Logger.Info("xapp-frame shutdown forced exit")
 113                                         os.Exit(0)
 114                                 }
 115                                 continue
 116                         }
 117
 118                 }
 119         }()
 120 }
 121
 122 func init() {
 123         // Load xapp configuration
 124         Logger = LoadConfig()
 125
 126         Logger.SetLevel(viper.GetInt("controls.logger.level"))
 127         Resource = NewRouter()
 128         Config = Configurator{}
 129         Metric = NewMetrics(viper.GetString("metrics.url"), viper.GetString("metrics.namespace"), Resource.router)
 130         Subscription = NewSubscriber(viper.GetString("subscription.host"), viper.GetInt("subscription.timeout"))
 131         Sdl = NewSDLClient(viper.GetString("db.namespace"))
 132         Rnib = NewRNIBClient()
 133
 134         InstallSignalHandler()
 135 }
 136
 137 func RunWithParams(c MessageConsumer, sdlcheck bool) {
 138         Rmr = NewRMRClient()
 139         Rmr.SetReadyCB(XappReadyCb, nil)
 140
 141         host := fmt.Sprintf(":%d", GetPortData("http").Port)
 142         go http.ListenAndServe(host, Resource.router)
 143         Logger.Info(fmt.Sprintf("Xapp started, listening on: %s", host))
 144         if sdlcheck {
 145                 Sdl.TestConnection()
 146         }
 147         Rmr.Start(c)
 148 }
 149
 150 func Run(c MessageConsumer) {
 151         RunWithParams(c, true)
 152 }