github.com/Shopify/docker@v1.13.1/oci/devices_linux.go (about)

     1  package oci
     2  
     3  import (
     4  	"fmt"
     5  	"os"
     6  	"path/filepath"
     7  	"strings"
     8  
     9  	"github.com/opencontainers/runc/libcontainer/configs"
    10  	"github.com/opencontainers/runc/libcontainer/devices"
    11  	specs "github.com/opencontainers/runtime-spec/specs-go"
    12  )
    13  
    14  // Device transforms a libcontainer configs.Device to a specs.Device object.
    15  func Device(d *configs.Device) specs.Device {
    16  	return specs.Device{
    17  		Type:     string(d.Type),
    18  		Path:     d.Path,
    19  		Major:    d.Major,
    20  		Minor:    d.Minor,
    21  		FileMode: fmPtr(int64(d.FileMode)),
    22  		UID:      u32Ptr(int64(d.Uid)),
    23  		GID:      u32Ptr(int64(d.Gid)),
    24  	}
    25  }
    26  
    27  func deviceCgroup(d *configs.Device) specs.DeviceCgroup {
    28  	t := string(d.Type)
    29  	return specs.DeviceCgroup{
    30  		Allow:  true,
    31  		Type:   &t,
    32  		Major:  &d.Major,
    33  		Minor:  &d.Minor,
    34  		Access: &d.Permissions,
    35  	}
    36  }
    37  
    38  // DevicesFromPath computes a list of devices and device permissions from paths (pathOnHost and pathInContainer) and cgroup permissions.
    39  func DevicesFromPath(pathOnHost, pathInContainer, cgroupPermissions string) (devs []specs.Device, devPermissions []specs.DeviceCgroup, err error) {
    40  	resolvedPathOnHost := pathOnHost
    41  
    42  	// check if it is a symbolic link
    43  	if src, e := os.Lstat(pathOnHost); e == nil && src.Mode()&os.ModeSymlink == os.ModeSymlink {
    44  		if linkedPathOnHost, e := filepath.EvalSymlinks(pathOnHost); e == nil {
    45  			resolvedPathOnHost = linkedPathOnHost
    46  		}
    47  	}
    48  
    49  	device, err := devices.DeviceFromPath(resolvedPathOnHost, cgroupPermissions)
    50  	// if there was no error, return the device
    51  	if err == nil {
    52  		device.Path = pathInContainer
    53  		return append(devs, Device(device)), append(devPermissions, deviceCgroup(device)), nil
    54  	}
    55  
    56  	// if the device is not a device node
    57  	// try to see if it's a directory holding many devices
    58  	if err == devices.ErrNotADevice {
    59  
    60  		// check if it is a directory
    61  		if src, e := os.Stat(resolvedPathOnHost); e == nil && src.IsDir() {
    62  
    63  			// mount the internal devices recursively
    64  			filepath.Walk(resolvedPathOnHost, func(dpath string, f os.FileInfo, e error) error {
    65  				childDevice, e := devices.DeviceFromPath(dpath, cgroupPermissions)
    66  				if e != nil {
    67  					// ignore the device
    68  					return nil
    69  				}
    70  
    71  				// add the device to userSpecified devices
    72  				childDevice.Path = strings.Replace(dpath, resolvedPathOnHost, pathInContainer, 1)
    73  				devs = append(devs, Device(childDevice))
    74  				devPermissions = append(devPermissions, deviceCgroup(childDevice))
    75  
    76  				return nil
    77  			})
    78  		}
    79  	}
    80  
    81  	if len(devs) > 0 {
    82  		return devs, devPermissions, nil
    83  	}
    84  
    85  	return devs, devPermissions, fmt.Errorf("error gathering device information while adding custom device %q: %s", pathOnHost, err)
    86  }