gvisor.dev/gvisor@v0.0.0-20240520182842-f9d4d51c7e0f/pkg/shim/state.go (about)

     1  // Copyright 2020 The gVisor Authors.
     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  //     https://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 shim
    16  
    17  import (
    18  	"encoding/json"
    19  	"io/ioutil"
    20  	"path/filepath"
    21  )
    22  
    23  const filename = "state.json"
    24  
    25  // state holds information needed between shim invocations.
    26  type state struct {
    27  	// Rootfs is the full path to the location rootfs was mounted.
    28  	Rootfs string `json:"rootfs"`
    29  
    30  	// Options is the configuration loaded from config.toml.
    31  	Options options `json:"options"`
    32  }
    33  
    34  func (s state) load(path string) error {
    35  	data, err := ioutil.ReadFile(filepath.Join(path, filename))
    36  	if err != nil {
    37  		return err
    38  	}
    39  	return json.Unmarshal(data, &s)
    40  }
    41  
    42  func (s state) save(path string) error {
    43  	data, err := json.Marshal(&s)
    44  	if err != nil {
    45  		return err
    46  	}
    47  	return ioutil.WriteFile(filepath.Join(path, filename), data, 0644)
    48  }