github.com/jiasir/docker@v1.3.3-0.20170609024000-252e610103e7/daemon/checkpoint.go (about)

     1  package daemon
     2  
     3  import (
     4  	"encoding/json"
     5  	"fmt"
     6  	"io/ioutil"
     7  	"os"
     8  	"path/filepath"
     9  
    10  	"github.com/docker/docker/api"
    11  	"github.com/docker/docker/api/types"
    12  )
    13  
    14  var (
    15  	validCheckpointNameChars   = api.RestrictedNameChars
    16  	validCheckpointNamePattern = api.RestrictedNamePattern
    17  )
    18  
    19  // getCheckpointDir verifies checkpoint directory for create,remove, list options and checks if checkpoint already exists
    20  func getCheckpointDir(checkDir, checkpointID string, ctrName string, ctrID string, ctrCheckpointDir string, create bool) (string, error) {
    21  	var checkpointDir string
    22  	var err2 error
    23  	if checkDir != "" {
    24  		checkpointDir = filepath.Join(checkDir, ctrID, "checkpoints")
    25  	} else {
    26  		checkpointDir = ctrCheckpointDir
    27  	}
    28  	checkpointAbsDir := filepath.Join(checkpointDir, checkpointID)
    29  	stat, err := os.Stat(checkpointAbsDir)
    30  	if create {
    31  		switch {
    32  		case err == nil && stat.IsDir():
    33  			err2 = fmt.Errorf("checkpoint with name %s already exists for container %s", checkpointID, ctrName)
    34  		case err != nil && os.IsNotExist(err):
    35  			err2 = nil
    36  		case err != nil:
    37  			err2 = err
    38  		case err == nil:
    39  			err2 = fmt.Errorf("%s exists and is not a directory", checkpointAbsDir)
    40  		}
    41  	} else {
    42  		switch {
    43  		case err != nil:
    44  			err2 = fmt.Errorf("checkpoint %s does not exists for container %s", checkpointID, ctrName)
    45  		case err == nil && stat.IsDir():
    46  			err2 = nil
    47  		case err == nil:
    48  			err2 = fmt.Errorf("%s exists and is not a directory", checkpointAbsDir)
    49  		}
    50  	}
    51  	return checkpointDir, err2
    52  }
    53  
    54  // CheckpointCreate checkpoints the process running in a container with CRIU
    55  func (daemon *Daemon) CheckpointCreate(name string, config types.CheckpointCreateOptions) error {
    56  	container, err := daemon.GetContainer(name)
    57  	if err != nil {
    58  		return err
    59  	}
    60  
    61  	if !container.IsRunning() {
    62  		return fmt.Errorf("Container %s not running", name)
    63  	}
    64  
    65  	if !validCheckpointNamePattern.MatchString(config.CheckpointID) {
    66  		return fmt.Errorf("Invalid checkpoint ID (%s), only %s are allowed", config.CheckpointID, validCheckpointNameChars)
    67  	}
    68  
    69  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), true)
    70  	if err != nil {
    71  		return fmt.Errorf("cannot checkpoint container %s: %s", name, err)
    72  	}
    73  
    74  	err = daemon.containerd.CreateCheckpoint(container.ID, config.CheckpointID, checkpointDir, config.Exit)
    75  	if err != nil {
    76  		return fmt.Errorf("Cannot checkpoint container %s: %s", name, err)
    77  	}
    78  
    79  	daemon.LogContainerEvent(container, "checkpoint")
    80  
    81  	return nil
    82  }
    83  
    84  // CheckpointDelete deletes the specified checkpoint
    85  func (daemon *Daemon) CheckpointDelete(name string, config types.CheckpointDeleteOptions) error {
    86  	container, err := daemon.GetContainer(name)
    87  	if err != nil {
    88  		return err
    89  	}
    90  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), false)
    91  	if err == nil {
    92  		return os.RemoveAll(filepath.Join(checkpointDir, config.CheckpointID))
    93  	}
    94  	return err
    95  }
    96  
    97  // CheckpointList lists all checkpoints of the specified container
    98  func (daemon *Daemon) CheckpointList(name string, config types.CheckpointListOptions) ([]types.Checkpoint, error) {
    99  	var out []types.Checkpoint
   100  
   101  	container, err := daemon.GetContainer(name)
   102  	if err != nil {
   103  		return nil, err
   104  	}
   105  
   106  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, "", name, container.ID, container.CheckpointDir(), false)
   107  	if err != nil {
   108  		return nil, err
   109  	}
   110  
   111  	if err := os.MkdirAll(checkpointDir, 0755); err != nil {
   112  		return nil, err
   113  	}
   114  
   115  	dirs, err := ioutil.ReadDir(checkpointDir)
   116  	if err != nil {
   117  		return nil, err
   118  	}
   119  
   120  	for _, d := range dirs {
   121  		if !d.IsDir() {
   122  			continue
   123  		}
   124  		path := filepath.Join(checkpointDir, d.Name(), "config.json")
   125  		data, err := ioutil.ReadFile(path)
   126  		if err != nil {
   127  			return nil, err
   128  		}
   129  		var cpt types.Checkpoint
   130  		if err := json.Unmarshal(data, &cpt); err != nil {
   131  			return nil, err
   132  		}
   133  		out = append(out, cpt)
   134  	}
   135  
   136  	return out, nil
   137  }