github.com/rawahars/moby@v24.0.4+incompatible/daemon/checkpoint.go (about)

     1  package daemon // import "github.com/docker/docker/daemon"
     2  
     3  import (
     4  	"context"
     5  	"fmt"
     6  	"os"
     7  	"path/filepath"
     8  
     9  	"github.com/docker/docker/api/types"
    10  	"github.com/docker/docker/daemon/names"
    11  )
    12  
    13  var (
    14  	validCheckpointNameChars   = names.RestrictedNameChars
    15  	validCheckpointNamePattern = names.RestrictedNamePattern
    16  )
    17  
    18  // getCheckpointDir verifies checkpoint directory for create,remove, list options and checks if checkpoint already exists
    19  func getCheckpointDir(checkDir, checkpointID, ctrName, ctrID, ctrCheckpointDir string, create bool) (string, error) {
    20  	var checkpointDir string
    21  	var err2 error
    22  	if checkDir != "" {
    23  		checkpointDir = checkDir
    24  	} else {
    25  		checkpointDir = ctrCheckpointDir
    26  	}
    27  	checkpointAbsDir := filepath.Join(checkpointDir, checkpointID)
    28  	stat, err := os.Stat(checkpointAbsDir)
    29  	if create {
    30  		switch {
    31  		case err == nil && stat.IsDir():
    32  			err2 = fmt.Errorf("checkpoint with name %s already exists for container %s", checkpointID, ctrName)
    33  		case err != nil && os.IsNotExist(err):
    34  			err2 = os.MkdirAll(checkpointAbsDir, 0700)
    35  		case err != nil:
    36  			err2 = err
    37  		default:
    38  			err2 = fmt.Errorf("%s exists and is not a directory", checkpointAbsDir)
    39  		}
    40  	} else {
    41  		switch {
    42  		case err != nil:
    43  			err2 = fmt.Errorf("checkpoint %s does not exist for container %s", checkpointID, ctrName)
    44  		case stat.IsDir():
    45  			err2 = nil
    46  		default:
    47  			err2 = fmt.Errorf("%s exists and is not a directory", checkpointAbsDir)
    48  		}
    49  	}
    50  	return checkpointAbsDir, err2
    51  }
    52  
    53  // CheckpointCreate checkpoints the process running in a container with CRIU
    54  func (daemon *Daemon) CheckpointCreate(name string, config types.CheckpointCreateOptions) error {
    55  	container, err := daemon.GetContainer(name)
    56  	if err != nil {
    57  		return err
    58  	}
    59  
    60  	container.Lock()
    61  	tsk, err := container.GetRunningTask()
    62  	container.Unlock()
    63  	if err != nil {
    64  		return err
    65  	}
    66  
    67  	if !validCheckpointNamePattern.MatchString(config.CheckpointID) {
    68  		return fmt.Errorf("Invalid checkpoint ID (%s), only %s are allowed", config.CheckpointID, validCheckpointNameChars)
    69  	}
    70  
    71  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), true)
    72  	if err != nil {
    73  		return fmt.Errorf("cannot checkpoint container %s: %s", name, err)
    74  	}
    75  
    76  	err = tsk.CreateCheckpoint(context.Background(), checkpointDir, config.Exit)
    77  	if err != nil {
    78  		os.RemoveAll(checkpointDir)
    79  		return fmt.Errorf("Cannot checkpoint container %s: %s", name, err)
    80  	}
    81  
    82  	daemon.LogContainerEvent(container, "checkpoint")
    83  
    84  	return nil
    85  }
    86  
    87  // CheckpointDelete deletes the specified checkpoint
    88  func (daemon *Daemon) CheckpointDelete(name string, config types.CheckpointDeleteOptions) error {
    89  	container, err := daemon.GetContainer(name)
    90  	if err != nil {
    91  		return err
    92  	}
    93  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), false)
    94  	if err == nil {
    95  		return os.RemoveAll(checkpointDir)
    96  	}
    97  	return err
    98  }
    99  
   100  // CheckpointList lists all checkpoints of the specified container
   101  func (daemon *Daemon) CheckpointList(name string, config types.CheckpointListOptions) ([]types.Checkpoint, error) {
   102  	var out []types.Checkpoint
   103  
   104  	container, err := daemon.GetContainer(name)
   105  	if err != nil {
   106  		return nil, err
   107  	}
   108  
   109  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, "", name, container.ID, container.CheckpointDir(), false)
   110  	if err != nil {
   111  		return nil, err
   112  	}
   113  
   114  	if err := os.MkdirAll(checkpointDir, 0755); err != nil {
   115  		return nil, err
   116  	}
   117  
   118  	dirs, err := os.ReadDir(checkpointDir)
   119  	if err != nil {
   120  		return nil, err
   121  	}
   122  
   123  	for _, d := range dirs {
   124  		if !d.IsDir() {
   125  			continue
   126  		}
   127  		cpt := types.Checkpoint{Name: d.Name()}
   128  		out = append(out, cpt)
   129  	}
   130  
   131  	return out, nil
   132  }