github.com/moby/docker@v26.1.3+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/checkpoint"
    10  	"github.com/docker/docker/api/types/events"
    11  	"github.com/docker/docker/daemon/names"
    12  )
    13  
    14  var (
    15  	validCheckpointNameChars   = names.RestrictedNameChars
    16  	validCheckpointNamePattern = names.RestrictedNamePattern
    17  )
    18  
    19  // getCheckpointDir verifies checkpoint directory for create,remove, list options and checks if checkpoint already exists
    20  func getCheckpointDir(checkDir, checkpointID, ctrName, ctrID, ctrCheckpointDir string, create bool) (string, error) {
    21  	var checkpointDir string
    22  	var err2 error
    23  	if checkDir != "" {
    24  		checkpointDir = checkDir
    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 = os.MkdirAll(checkpointAbsDir, 0o700)
    36  		case err != nil:
    37  			err2 = err
    38  		default:
    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 exist for container %s", checkpointID, ctrName)
    45  		case stat.IsDir():
    46  			err2 = nil
    47  		default:
    48  			err2 = fmt.Errorf("%s exists and is not a directory", checkpointAbsDir)
    49  		}
    50  	}
    51  	return checkpointAbsDir, err2
    52  }
    53  
    54  // CheckpointCreate checkpoints the process running in a container with CRIU
    55  func (daemon *Daemon) CheckpointCreate(name string, config checkpoint.CreateOptions) error {
    56  	container, err := daemon.GetContainer(name)
    57  	if err != nil {
    58  		return err
    59  	}
    60  
    61  	container.Lock()
    62  	tsk, err := container.GetRunningTask()
    63  	container.Unlock()
    64  	if err != nil {
    65  		return err
    66  	}
    67  
    68  	if !validCheckpointNamePattern.MatchString(config.CheckpointID) {
    69  		return fmt.Errorf("Invalid checkpoint ID (%s), only %s are allowed", config.CheckpointID, validCheckpointNameChars)
    70  	}
    71  
    72  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), true)
    73  	if err != nil {
    74  		return fmt.Errorf("cannot checkpoint container %s: %s", name, err)
    75  	}
    76  
    77  	err = tsk.CreateCheckpoint(context.Background(), checkpointDir, config.Exit)
    78  	if err != nil {
    79  		os.RemoveAll(checkpointDir)
    80  		return fmt.Errorf("Cannot checkpoint container %s: %s", name, err)
    81  	}
    82  
    83  	daemon.LogContainerEvent(container, events.ActionCheckpoint)
    84  
    85  	return nil
    86  }
    87  
    88  // CheckpointDelete deletes the specified checkpoint
    89  func (daemon *Daemon) CheckpointDelete(name string, config checkpoint.DeleteOptions) error {
    90  	container, err := daemon.GetContainer(name)
    91  	if err != nil {
    92  		return err
    93  	}
    94  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, config.CheckpointID, name, container.ID, container.CheckpointDir(), false)
    95  	if err == nil {
    96  		return os.RemoveAll(checkpointDir)
    97  	}
    98  	return err
    99  }
   100  
   101  // CheckpointList lists all checkpoints of the specified container
   102  func (daemon *Daemon) CheckpointList(name string, config checkpoint.ListOptions) ([]checkpoint.Summary, error) {
   103  	var out []checkpoint.Summary
   104  
   105  	container, err := daemon.GetContainer(name)
   106  	if err != nil {
   107  		return nil, err
   108  	}
   109  
   110  	checkpointDir, err := getCheckpointDir(config.CheckpointDir, "", name, container.ID, container.CheckpointDir(), false)
   111  	if err != nil {
   112  		return nil, err
   113  	}
   114  
   115  	if err := os.MkdirAll(checkpointDir, 0o755); err != nil {
   116  		return nil, err
   117  	}
   118  
   119  	dirs, err := os.ReadDir(checkpointDir)
   120  	if err != nil {
   121  		return nil, err
   122  	}
   123  
   124  	for _, d := range dirs {
   125  		if !d.IsDir() {
   126  			continue
   127  		}
   128  		cpt := checkpoint.Summary{Name: d.Name()}
   129  		out = append(out, cpt)
   130  	}
   131  
   132  	return out, nil
   133  }