github.com/tri-adam/singularity@v3.1.1+incompatible/internal/app/singularity/oci_pause_linux.go (about)

     1  // Copyright (c) 2018-2019, Sylabs Inc. All rights reserved.
     2  // This software is licensed under a 3-clause BSD license. Please consult the
     3  // LICENSE.md file distributed with the sources of this project regarding your
     4  // rights to use or distribute this software.
     5  
     6  package singularity
     7  
     8  import (
     9  	"encoding/json"
    10  	"fmt"
    11  	"io"
    12  
    13  	"github.com/sylabs/singularity/pkg/ociruntime"
    14  	"github.com/sylabs/singularity/pkg/util/unix"
    15  )
    16  
    17  // OciPauseResume pauses/resumes processes in a container
    18  func OciPauseResume(containerID string, pause bool) error {
    19  	state, err := getState(containerID)
    20  	if err != nil {
    21  		return err
    22  	}
    23  
    24  	if state.ControlSocket == "" {
    25  		return fmt.Errorf("can't find control socket")
    26  	}
    27  
    28  	if pause && state.Status != ociruntime.Running {
    29  		return fmt.Errorf("container %s is not running", containerID)
    30  	} else if !pause && state.Status != ociruntime.Paused {
    31  		return fmt.Errorf("container %s is not paused", containerID)
    32  	}
    33  
    34  	ctrl := &ociruntime.Control{}
    35  	if pause {
    36  		ctrl.Pause = true
    37  	} else {
    38  		ctrl.Resume = true
    39  	}
    40  
    41  	c, err := unix.Dial(state.ControlSocket)
    42  	if err != nil {
    43  		return fmt.Errorf("failed to connect to control socket")
    44  	}
    45  	defer c.Close()
    46  
    47  	enc := json.NewEncoder(c)
    48  	if err != nil {
    49  		return err
    50  	}
    51  
    52  	if err := enc.Encode(ctrl); err != nil {
    53  		return err
    54  	}
    55  
    56  	// wait runtime close socket connection for ACK
    57  	d := make([]byte, 1)
    58  	if _, err := c.Read(d); err != io.EOF {
    59  		return err
    60  	}
    61  
    62  	// check status
    63  	state, err = getState(containerID)
    64  	if err != nil {
    65  		return err
    66  	}
    67  	if pause && state.Status != ociruntime.Paused {
    68  		return fmt.Errorf("bad status %s returned instead of paused", state.Status)
    69  	} else if !pause && state.Status != ociruntime.Running {
    70  		return fmt.Errorf("bad status %s returned instead of running", state.Status)
    71  	}
    72  
    73  	return nil
    74  }