github.com/containerd/containerd@v22.0.0-20200918172823-438c87b8e050+incompatible/snapshots/devmapper/snapshotter_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 devmapper
    20  
    21  import (
    22  	"context"
    23  	_ "crypto/sha256"
    24  	"fmt"
    25  	"io/ioutil"
    26  	"os"
    27  	"testing"
    28  	"time"
    29  
    30  	"github.com/containerd/continuity/fs/fstest"
    31  	"github.com/hashicorp/go-multierror"
    32  	"github.com/sirupsen/logrus"
    33  	"gotest.tools/v3/assert"
    34  
    35  	"github.com/containerd/containerd/mount"
    36  	"github.com/containerd/containerd/namespaces"
    37  	"github.com/containerd/containerd/pkg/testutil"
    38  	"github.com/containerd/containerd/snapshots"
    39  	"github.com/containerd/containerd/snapshots/devmapper/dmsetup"
    40  	"github.com/containerd/containerd/snapshots/devmapper/losetup"
    41  	"github.com/containerd/containerd/snapshots/testsuite"
    42  )
    43  
    44  func TestSnapshotterSuite(t *testing.T) {
    45  	testutil.RequiresRoot(t)
    46  
    47  	logrus.SetLevel(logrus.DebugLevel)
    48  
    49  	snapshotterFn := func(ctx context.Context, root string) (snapshots.Snapshotter, func() error, error) {
    50  		// Create loopback devices for each test case
    51  		_, loopDataDevice := createLoopbackDevice(t, root)
    52  		_, loopMetaDevice := createLoopbackDevice(t, root)
    53  
    54  		poolName := fmt.Sprintf("containerd-snapshotter-suite-pool-%d", time.Now().Nanosecond())
    55  		err := dmsetup.CreatePool(poolName, loopDataDevice, loopMetaDevice, 64*1024/dmsetup.SectorSize)
    56  		assert.NilError(t, err, "failed to create pool %q", poolName)
    57  
    58  		config := &Config{
    59  			RootPath:      root,
    60  			PoolName:      poolName,
    61  			BaseImageSize: "16Mb",
    62  		}
    63  
    64  		snap, err := NewSnapshotter(context.Background(), config)
    65  		if err != nil {
    66  			return nil, nil, err
    67  		}
    68  
    69  		// Remove device mapper pool and detach loop devices after test completes
    70  		removePool := func() error {
    71  			result := multierror.Append(
    72  				snap.pool.RemovePool(ctx),
    73  				losetup.DetachLoopDevice(loopDataDevice, loopMetaDevice))
    74  
    75  			return result.ErrorOrNil()
    76  		}
    77  
    78  		// Pool cleanup should be called before closing metadata store (as we need to retrieve device names)
    79  		snap.cleanupFn = append([]closeFunc{removePool}, snap.cleanupFn...)
    80  
    81  		return snap, snap.Close, nil
    82  	}
    83  
    84  	testsuite.SnapshotterSuite(t, "devmapper", snapshotterFn)
    85  
    86  	ctx := context.Background()
    87  	ctx = namespaces.WithNamespace(ctx, "testsuite")
    88  
    89  	t.Run("DevMapperUsage", func(t *testing.T) {
    90  		tempDir, err := ioutil.TempDir("", "snapshot-suite-usage")
    91  		assert.NilError(t, err)
    92  		defer os.RemoveAll(tempDir)
    93  
    94  		snapshotter, closer, err := snapshotterFn(ctx, tempDir)
    95  		assert.NilError(t, err)
    96  		defer closer()
    97  
    98  		testUsage(t, snapshotter)
    99  	})
   100  }
   101  
   102  // testUsage tests devmapper's Usage implementation. This is an approximate test as it's hard to
   103  // predict how many blocks will be consumed under different conditions and parameters.
   104  func testUsage(t *testing.T, snapshotter snapshots.Snapshotter) {
   105  	ctx := context.Background()
   106  
   107  	// Create empty base layer
   108  	_, err := snapshotter.Prepare(ctx, "prepare-1", "")
   109  	assert.NilError(t, err)
   110  
   111  	emptyLayerUsage, err := snapshotter.Usage(ctx, "prepare-1")
   112  	assert.NilError(t, err)
   113  
   114  	// Should be > 0 as just written file system also consumes blocks
   115  	assert.Assert(t, emptyLayerUsage.Size > 0)
   116  
   117  	err = snapshotter.Commit(ctx, "layer-1", "prepare-1")
   118  	assert.NilError(t, err)
   119  
   120  	// Create child layer with 1MB file
   121  
   122  	var (
   123  		sizeBytes   int64 = 1048576 // 1MB
   124  		baseApplier       = fstest.Apply(fstest.CreateRandomFile("/a", 12345679, sizeBytes, 0777))
   125  	)
   126  
   127  	mounts, err := snapshotter.Prepare(ctx, "prepare-2", "layer-1")
   128  	assert.NilError(t, err)
   129  
   130  	err = mount.WithTempMount(ctx, mounts, baseApplier.Apply)
   131  	assert.NilError(t, err)
   132  
   133  	err = snapshotter.Commit(ctx, "layer-2", "prepare-2")
   134  	assert.NilError(t, err)
   135  
   136  	layer2Usage, err := snapshotter.Usage(ctx, "layer-2")
   137  	assert.NilError(t, err)
   138  
   139  	// Should be at least 1 MB + fs metadata
   140  	assert.Assert(t, layer2Usage.Size > sizeBytes)
   141  	assert.Assert(t, layer2Usage.Size < sizeBytes+256*dmsetup.SectorSize)
   142  }