github.com/containerd/containerd@v22.0.0-20200918172823-438c87b8e050+incompatible/snapshots/devmapper/losetup/losetup_test.go (about)

     1  // +build linux
     2  
     3  /*
     4     Copyright The containerd Authors.
     5  
     6     Licensed under the Apache License, Version 2.0 (the "License");
     7     you may not use this file except in compliance with the License.
     8     You may obtain a copy of the License at
     9  
    10         http://www.apache.org/licenses/LICENSE-2.0
    11  
    12     Unless required by applicable law or agreed to in writing, software
    13     distributed under the License is distributed on an "AS IS" BASIS,
    14     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    15     See the License for the specific language governing permissions and
    16     limitations under the License.
    17  */
    18  
    19  package losetup
    20  
    21  import (
    22  	"io/ioutil"
    23  	"os"
    24  	"testing"
    25  
    26  	"github.com/docker/go-units"
    27  	"golang.org/x/sys/unix"
    28  	"gotest.tools/v3/assert"
    29  	is "gotest.tools/v3/assert/cmp"
    30  
    31  	"github.com/containerd/containerd/pkg/testutil"
    32  )
    33  
    34  func TestLosetup(t *testing.T) {
    35  	testutil.RequiresRoot(t)
    36  
    37  	var (
    38  		imagePath   = createSparseImage(t)
    39  		loopDevice1 string
    40  		loopDevice2 string
    41  	)
    42  
    43  	defer func() {
    44  		err := os.Remove(imagePath)
    45  		assert.NilError(t, err)
    46  	}()
    47  
    48  	t.Run("AttachLoopDevice", func(t *testing.T) {
    49  		dev1, err := AttachLoopDevice(imagePath)
    50  		assert.NilError(t, err)
    51  		assert.Assert(t, dev1 != "")
    52  
    53  		dev2, err := AttachLoopDevice(imagePath)
    54  		assert.NilError(t, err)
    55  		assert.Assert(t, dev2 != dev1, "should attach different loop device")
    56  
    57  		loopDevice1 = dev1
    58  		loopDevice2 = dev2
    59  	})
    60  
    61  	t.Run("AttachEmptyLoopDevice", func(t *testing.T) {
    62  		_, err := AttachLoopDevice("")
    63  		assert.Assert(t, err != nil, "shouldn't attach empty path")
    64  	})
    65  
    66  	t.Run("FindAssociatedLoopDevices", func(t *testing.T) {
    67  		devices, err := FindAssociatedLoopDevices(imagePath)
    68  		assert.NilError(t, err)
    69  		assert.Assert(t, is.Len(devices, 2), "unexpected number of attached devices")
    70  		assert.Assert(t, is.Contains(devices, loopDevice1))
    71  		assert.Assert(t, is.Contains(devices, loopDevice2))
    72  	})
    73  
    74  	t.Run("FindAssociatedLoopDevicesForInvalidImage", func(t *testing.T) {
    75  		devices, err := FindAssociatedLoopDevices("")
    76  		assert.NilError(t, err)
    77  		assert.Assert(t, is.Len(devices, 0))
    78  	})
    79  
    80  	t.Run("DetachLoopDevice", func(t *testing.T) {
    81  		err := DetachLoopDevice(loopDevice2)
    82  		assert.NilError(t, err, "failed to detach %q", loopDevice2)
    83  	})
    84  
    85  	t.Run("DetachEmptyDevice", func(t *testing.T) {
    86  		err := DetachLoopDevice("")
    87  		assert.Assert(t, err != nil, "shouldn't detach empty path")
    88  	})
    89  
    90  	t.Run("RemoveLoopDevicesAssociatedWithImage", func(t *testing.T) {
    91  		err := RemoveLoopDevicesAssociatedWithImage(imagePath)
    92  		assert.NilError(t, err)
    93  
    94  		devices, err := FindAssociatedLoopDevices(imagePath)
    95  		assert.NilError(t, err)
    96  		assert.Assert(t, is.Len(devices, 0))
    97  	})
    98  
    99  	t.Run("RemoveLoopDevicesAssociatedWithInvalidImage", func(t *testing.T) {
   100  		err := RemoveLoopDevicesAssociatedWithImage("")
   101  		assert.NilError(t, err)
   102  	})
   103  
   104  	t.Run("DetachInvalidDevice", func(t *testing.T) {
   105  		err := DetachLoopDevice("/dev/loop_invalid_idx")
   106  		assert.Equal(t, unix.ENOENT, err)
   107  	})
   108  }
   109  
   110  func createSparseImage(t *testing.T) string {
   111  	file, err := ioutil.TempFile("", "losetup-tests-")
   112  	assert.NilError(t, err)
   113  
   114  	size, err := units.RAMInBytes("16Mb")
   115  	assert.NilError(t, err)
   116  
   117  	err = file.Truncate(size)
   118  	assert.NilError(t, err)
   119  
   120  	err = file.Close()
   121  	assert.NilError(t, err)
   122  
   123  	return file.Name()
   124  }