github.com/mirantis/virtlet@v1.5.2-0.20191204181327-1659b8a48e9b/pkg/image/virtualsize_test.go (about)

     1  /*
     2  Copyright 2018 Mirantis
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package image
    18  
    19  import (
    20  	"io/ioutil"
    21  	"os"
    22  	"os/exec"
    23  	"path/filepath"
    24  	"runtime"
    25  	"testing"
    26  )
    27  
    28  const (
    29  	expectedImageSize = 10485760
    30  )
    31  
    32  // Here's how this test was made:
    33  // $ qemu-img create -f qcow2 /tmp/foobar.qcow2 10M
    34  // Formatting '/tmp/foobar.qcow2', fmt=qcow2 size=10485760 encryption=off cluster_size=65536 lazy_refcounts=off refcount_bits=16
    35  // $ qemu-img info --output json /tmp/foobar.qcow2
    36  // {
    37  // 	"virtual-size": 10485760,
    38  // 	"filename": "/tmp/foobar.qcow2",
    39  // 	"cluster-size": 65536,
    40  // 	"format": "qcow2",
    41  // 	"actual-size": 200704,
    42  // 	"format-specific": {
    43  // 		"type": "qcow2",
    44  // 		"data": {
    45  // 			"compat": "1.1",
    46  // 			"lazy-refcounts": false,
    47  // 			"refcount-bits": 16,
    48  // 			"corrupt": false
    49  // 		}
    50  // 	},
    51  // 	"dirty-flag": false
    52  // }
    53  
    54  func TestImageSize(t *testing.T) {
    55  	// it may be possible to run it on non-Linux systems but
    56  	// that would require installing qemu-img tools
    57  	if runtime.GOOS != "linux" {
    58  		t.Skip("ImageSize only works on Linux")
    59  	}
    60  
    61  	tmpDir, err := ioutil.TempDir("", "images")
    62  	if err != nil {
    63  		t.Fatalf("TempDir(): %v", err)
    64  	}
    65  	defer os.RemoveAll(tmpDir)
    66  
    67  	imagePath := filepath.Join(tmpDir, "image.qcow2")
    68  	if out, err := exec.Command("qemu-img", "create", "-f", "qcow2", imagePath, "10M").CombinedOutput(); err != nil {
    69  		t.Fatalf("qemu-img create: %q: %v\noutput:\n%v", imagePath, err, out)
    70  	}
    71  
    72  	imageSize, err := GetImageVirtualSize(imagePath)
    73  	if err != nil {
    74  		t.Fatalf("GetImageSize(): %q: %v", imagePath, err)
    75  	}
    76  
    77  	if imageSize != expectedImageSize {
    78  		t.Errorf("bad image size: %d instead of %d", imageSize, expectedImageSize)
    79  	}
    80  }