github.com/coreos/mantle@v0.13.0/util/image.go (about)

     1  // Copyright 2018 Red Hat
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package util
    16  
    17  import (
    18  	"encoding/json"
    19  	"os/exec"
    20  )
    21  
    22  type ImageInfo struct {
    23  	Format      string `json:"format"`
    24  	VirtualSize uint64 `json:"virtual-size"`
    25  }
    26  
    27  func GetImageInfo(path string) (*ImageInfo, error) {
    28  	out, err := exec.Command("qemu-img", "info", "--output=json", path).Output()
    29  	if err != nil {
    30  		return nil, err
    31  	}
    32  
    33  	var info ImageInfo
    34  	err = json.Unmarshal(out, &info)
    35  	if err != nil {
    36  		return nil, err
    37  	}
    38  	return &info, nil
    39  }