github.com/fafucoder/cilium@v1.6.11/pkg/launcher/launcher.go (about)

     1  // Copyright 2017 Authors of Cilium
     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 launcher
    16  
    17  import (
    18  	"fmt"
    19  	"io"
    20  	"os"
    21  	"os/exec"
    22  
    23  	"github.com/cilium/cilium/pkg/lock"
    24  	"github.com/cilium/cilium/pkg/logging"
    25  	"github.com/cilium/cilium/pkg/logging/logfields"
    26  
    27  	"github.com/sirupsen/logrus"
    28  )
    29  
    30  var log = logging.DefaultLogger.WithField(logfields.LogSubsys, "launcher")
    31  
    32  // Launcher is used to wrap the node executable binary.
    33  type Launcher struct {
    34  	Mutex   lock.RWMutex
    35  	target  string
    36  	args    []string
    37  	process *os.Process
    38  	stdout  io.ReadCloser
    39  }
    40  
    41  // Run starts the daemon.
    42  func (launcher *Launcher) Run() error {
    43  	targetName := launcher.GetTarget()
    44  	cmdStr := fmt.Sprintf("%s %s", targetName, launcher.GetArgs())
    45  	cmd := exec.Command(targetName, launcher.GetArgs()...)
    46  	cmd.Stderr = os.Stderr
    47  	stdout, _ := cmd.StdoutPipe()
    48  	if err := cmd.Start(); err != nil {
    49  		log.WithError(err).WithField("cmd", cmdStr).Error("cmd.Start()")
    50  		return fmt.Errorf("unable to launch process %s: %s", cmdStr, err)
    51  	}
    52  
    53  	launcher.setProcess(cmd.Process)
    54  	launcher.setStdout(stdout)
    55  
    56  	// Wait for the process to exit in the background to release all
    57  	// resources
    58  	go func() {
    59  		err := cmd.Wait()
    60  		log.WithFields(logrus.Fields{
    61  			"exitCode": err,
    62  			"cmd":      cmdStr,
    63  		}).Debug("Process exited")
    64  	}()
    65  
    66  	return nil
    67  }
    68  
    69  // SetTarget sets the Launcher target.
    70  func (launcher *Launcher) SetTarget(target string) {
    71  	launcher.Mutex.Lock()
    72  	launcher.target = target
    73  	launcher.Mutex.Unlock()
    74  }
    75  
    76  // GetTarget returns the Launcher target.
    77  func (launcher *Launcher) GetTarget() string {
    78  	launcher.Mutex.RLock()
    79  	arg := launcher.target
    80  	launcher.Mutex.RUnlock()
    81  	return arg
    82  }
    83  
    84  // SetArgs sets the Launcher arg.
    85  func (launcher *Launcher) SetArgs(args []string) {
    86  	launcher.Mutex.Lock()
    87  	launcher.args = args
    88  	launcher.Mutex.Unlock()
    89  }
    90  
    91  // GetArgs returns the Launcher arg.
    92  func (launcher *Launcher) GetArgs() []string {
    93  	launcher.Mutex.RLock()
    94  	args := launcher.args
    95  	launcher.Mutex.RUnlock()
    96  	return args
    97  }
    98  
    99  // setProcess sets the internal process with the given process.
   100  func (launcher *Launcher) setProcess(proc *os.Process) {
   101  	launcher.Mutex.Lock()
   102  	launcher.process = proc
   103  	launcher.Mutex.Unlock()
   104  }
   105  
   106  // GetProcess returns the internal process.
   107  func (launcher *Launcher) GetProcess() *os.Process {
   108  	launcher.Mutex.RLock()
   109  	proc := launcher.process
   110  	launcher.Mutex.RUnlock()
   111  	return proc
   112  }
   113  
   114  // setStdout sets the stdout pipe.
   115  func (launcher *Launcher) setStdout(stdout io.ReadCloser) {
   116  	launcher.Mutex.Lock()
   117  	launcher.stdout = stdout
   118  	launcher.Mutex.Unlock()
   119  }
   120  
   121  // GetStdout gets the stdout pipe.
   122  func (launcher *Launcher) GetStdout() io.ReadCloser {
   123  	launcher.Mutex.RLock()
   124  	stdout := launcher.stdout
   125  	launcher.Mutex.RUnlock()
   126  	return stdout
   127  }