go.ligato.io/vpp-agent/v3@v3.5.0/pkg/debug/debug.go (about)

     1  //  Copyright (c) 2019 Cisco and/or its affiliates.
     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 debug
    16  
    17  import (
    18  	_ "expvar"
    19  	"log"
    20  	"net/http"
    21  	_ "net/http/pprof"
    22  	"os"
    23  	"strconv"
    24  	"strings"
    25  
    26  	"github.com/pkg/profile"
    27  )
    28  
    29  const (
    30  	defaultServerAddr     = ":1234"
    31  	defaultMemProfileRate = 1024
    32  )
    33  
    34  var (
    35  	debugServerAddr = os.Getenv("DEBUG_SERVER_ADDR")
    36  
    37  	profileMode    = os.Getenv("DEBUG_PROFILE_MODE")
    38  	profilePath    = os.Getenv("DEBUG_PROFILE_PATH")
    39  	profileMemRate = os.Getenv("DEBUG_PROFILE_MEMRATE")
    40  )
    41  
    42  type Debug struct {
    43  	closer func()
    44  }
    45  
    46  func Start() interface {
    47  	Stop()
    48  } {
    49  	var d Debug
    50  
    51  	d.runProfiling()
    52  
    53  	d.runServer()
    54  
    55  	return &d
    56  }
    57  
    58  func (d *Debug) Stop() {
    59  	if d.closer != nil {
    60  		d.closer()
    61  	}
    62  }
    63  
    64  func (d *Debug) runProfiling() {
    65  	var profiling func(*profile.Profile)
    66  
    67  	memRate := defaultMemProfileRate
    68  	if profileMemRate != "" {
    69  		if x, err := strconv.Atoi(profileMemRate); err == nil {
    70  			memRate = x
    71  		}
    72  	}
    73  
    74  	switch strings.ToLower(profileMode) {
    75  	case "cpu":
    76  		profiling = profile.CPUProfile
    77  	case "mem":
    78  		profiling = profile.MemProfileRate(memRate)
    79  	case "mutex":
    80  		profiling = profile.MutexProfile
    81  	case "block":
    82  		profiling = profile.BlockProfile
    83  	case "trace":
    84  		profiling = profile.TraceProfile
    85  	default:
    86  		// do nothing
    87  		return
    88  	}
    89  
    90  	opts := []func(*profile.Profile){
    91  		profiling,
    92  		profile.ProfilePath(profilePath),
    93  		profile.NoShutdownHook,
    94  	}
    95  
    96  	d.closer = profile.Start(opts...).Stop
    97  }
    98  
    99  func (d *Debug) runServer() {
   100  	addr := debugServerAddr
   101  	if addr == "" {
   102  		addr = defaultServerAddr
   103  	}
   104  
   105  	log.Printf("debug server listening on: %s", addr)
   106  
   107  	go func() {
   108  		if err := http.ListenAndServe(addr, nil); err != nil {
   109  			log.Printf("debug server error: %v", err)
   110  		}
   111  	}()
   112  }