github.com/SagerNet/gvisor@v0.0.0-20210707092255-7731c139d75c/pkg/shim/utils/utils.go (about)

     1  // Copyright 2018 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 utils container miscellaneous utility function used by the shim.
    16  package utils
    17  
    18  import (
    19  	"encoding/json"
    20  	"io/ioutil"
    21  	"path/filepath"
    22  
    23  	specs "github.com/opencontainers/runtime-spec/specs-go"
    24  )
    25  
    26  const configFilename = "config.json"
    27  
    28  // ReadSpec reads OCI spec from the bundle directory.
    29  func ReadSpec(bundle string) (*specs.Spec, error) {
    30  	b, err := ioutil.ReadFile(filepath.Join(bundle, configFilename))
    31  	if err != nil {
    32  		return nil, err
    33  	}
    34  	var spec specs.Spec
    35  	if err := json.Unmarshal(b, &spec); err != nil {
    36  		return nil, err
    37  	}
    38  	return &spec, nil
    39  }
    40  
    41  // WriteSpec writes OCI spec to the bundle directory.
    42  func WriteSpec(bundle string, spec *specs.Spec) error {
    43  	b, err := json.Marshal(spec)
    44  	if err != nil {
    45  		return err
    46  	}
    47  	return ioutil.WriteFile(filepath.Join(bundle, configFilename), b, 0666)
    48  }
    49  
    50  // IsSandbox checks whether a container is a sandbox container.
    51  func IsSandbox(spec *specs.Spec) bool {
    52  	t, ok := spec.Annotations[ContainerTypeAnnotation]
    53  	return !ok || t == containerTypeSandbox
    54  }
    55  
    56  // UserLogPath gets user log path from OCI annotation.
    57  func UserLogPath(spec *specs.Spec) string {
    58  	sandboxLogDir := spec.Annotations[sandboxLogDirAnnotation]
    59  	if sandboxLogDir == "" {
    60  		return ""
    61  	}
    62  	return filepath.Join(sandboxLogDir, "gvisor.log")
    63  }