mirror of
https://github.com/NVIDIA/nvidia-container-toolkit
synced 2024-11-22 16:29:18 +00:00
b6a585c77d
This change copies the cmd/nvidia-container-runtime, internal, and test folders from github.com/NVIDIA/nvidia-container-runtime@8a63b4b34f3ce3b4167f0516aa3f7207ca280dfb Signed-off-by: Evan Lezar <elezar@nvidia.com>
103 lines
2.6 KiB
Go
103 lines
2.6 KiB
Go
/*
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# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
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#
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# Licensed under the Apache License, Version 2.0 (the "License");
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# you may not use this file except in compliance with the License.
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# You may obtain a copy of the License at
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#
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# http://www.apache.org/licenses/LICENSE-2.0
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#
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# Unless required by applicable law or agreed to in writing, software
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# distributed under the License is distributed on an "AS IS" BASIS,
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# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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# See the License for the specific language governing permissions and
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# limitations under the License.
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*/
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package oci
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import (
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"encoding/json"
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"fmt"
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"os"
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oci "github.com/opencontainers/runtime-spec/specs-go"
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)
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// SpecModifier is a function that accepts a pointer to an OCI Srec and returns an
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// error. The intention is that the function would modify the spec in-place.
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type SpecModifier func(*oci.Spec) error
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// Spec defines the operations to be performed on an OCI specification
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type Spec interface {
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Load() error
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Flush() error
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Modify(SpecModifier) error
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}
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type fileSpec struct {
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*oci.Spec
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path string
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}
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var _ Spec = (*fileSpec)(nil)
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// NewSpecFromFile creates an object that encapsulates a file-backed OCI spec.
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// This can be used to read from the file, modify the spec, and write to the
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// same file.
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func NewSpecFromFile(filepath string) Spec {
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oci := fileSpec{
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path: filepath,
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}
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return &oci
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}
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// Load reads the contents of an OCI spec from file to be referenced internally.
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// The file is opened "read-only"
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func (s *fileSpec) Load() error {
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specFile, err := os.Open(s.path)
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if err != nil {
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return fmt.Errorf("error opening OCI specification file: %v", err)
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}
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defer specFile.Close()
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decoder := json.NewDecoder(specFile)
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var spec oci.Spec
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err = decoder.Decode(&spec)
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if err != nil {
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return fmt.Errorf("error reading OCI specification from file: %v", err)
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}
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s.Spec = &spec
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return nil
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}
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// Modify applies the specified SpecModifier to the stored OCI specification.
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func (s *fileSpec) Modify(f SpecModifier) error {
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if s.Spec == nil {
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return fmt.Errorf("no spec loaded for modification")
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}
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return f(s.Spec)
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}
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// Flush writes the stored OCI specification to the filepath specifed by the path member.
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// The file is truncated upon opening, overwriting any existing contents.
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func (s fileSpec) Flush() error {
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specFile, err := os.Create(s.path)
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if err != nil {
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return fmt.Errorf("error opening OCI specification file: %v", err)
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}
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defer specFile.Close()
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encoder := json.NewEncoder(specFile)
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err = encoder.Encode(s.Spec)
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if err != nil {
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return fmt.Errorf("error writing OCI specification to file: %v", err)
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}
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return nil
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}
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