mirror of
https://github.com/NVIDIA/nvidia-container-toolkit
synced 2024-11-24 04:54:00 +00:00
133 lines
3.9 KiB
Go
133 lines
3.9 KiB
Go
/*
|
|
# Copyright (c) 2021, NVIDIA CORPORATION. All rights reserved.
|
|
#
|
|
# Licensed under the Apache License, Version 2.0 (the "License");
|
|
# you may not use this file except in compliance with the License.
|
|
# You may obtain a copy of the License at
|
|
#
|
|
# http://www.apache.org/licenses/LICENSE-2.0
|
|
#
|
|
# Unless required by applicable law or agreed to in writing, software
|
|
# distributed under the License is distributed on an "AS IS" BASIS,
|
|
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
|
|
# See the License for the specific language governing permissions and
|
|
# limitations under the License.
|
|
*/
|
|
|
|
package main
|
|
|
|
import (
|
|
"fmt"
|
|
"os"
|
|
"os/exec"
|
|
"strings"
|
|
|
|
"github.com/NVIDIA/nvidia-container-toolkit/internal/oci"
|
|
"github.com/opencontainers/runtime-spec/specs-go"
|
|
log "github.com/sirupsen/logrus"
|
|
)
|
|
|
|
// nvidiaContainerRuntime encapsulates the NVIDIA Container Runtime. It wraps the specified runtime, conditionally
|
|
// modifying the specified OCI specification before invoking the runtime.
|
|
type nvidiaContainerRuntime struct {
|
|
logger *log.Logger
|
|
runtime oci.Runtime
|
|
ociSpec oci.Spec
|
|
}
|
|
|
|
var _ oci.Runtime = (*nvidiaContainerRuntime)(nil)
|
|
|
|
// newNvidiaContainerRuntime is a constructor for a standard runtime shim.
|
|
func newNvidiaContainerRuntimeWithLogger(logger *log.Logger, runtime oci.Runtime, ociSpec oci.Spec) (oci.Runtime, error) {
|
|
r := nvidiaContainerRuntime{
|
|
logger: logger,
|
|
runtime: runtime,
|
|
ociSpec: ociSpec,
|
|
}
|
|
|
|
return &r, nil
|
|
}
|
|
|
|
// Exec defines the entrypoint for the NVIDIA Container Runtime. A check is performed to see whether modifications
|
|
// to the OCI spec are required -- and applicable modifcations applied. The supplied arguments are then
|
|
// forwarded to the underlying runtime's Exec method.
|
|
func (r nvidiaContainerRuntime) Exec(args []string) error {
|
|
if r.modificationRequired(args) {
|
|
err := r.modifyOCISpec()
|
|
if err != nil {
|
|
return fmt.Errorf("error modifying OCI spec: %v", err)
|
|
}
|
|
}
|
|
|
|
r.logger.Println("Forwarding command to runtime")
|
|
return r.runtime.Exec(args)
|
|
}
|
|
|
|
// modificationRequired checks the intput arguments to determine whether a modification
|
|
// to the OCI spec is required.
|
|
func (r nvidiaContainerRuntime) modificationRequired(args []string) bool {
|
|
if oci.HasCreateSubcommand(args) {
|
|
r.logger.Infof("'create' command detected; modification required")
|
|
return true
|
|
}
|
|
|
|
r.logger.Infof("No modification required")
|
|
return false
|
|
}
|
|
|
|
// modifyOCISpec loads and modifies the OCI spec specified in the nvidiaContainerRuntime
|
|
// struct. The spec is modified in-place and written to the same file as the input after
|
|
// modifcationas are applied.
|
|
func (r nvidiaContainerRuntime) modifyOCISpec() error {
|
|
err := r.ociSpec.Load()
|
|
if err != nil {
|
|
return fmt.Errorf("error loading OCI specification for modification: %v", err)
|
|
}
|
|
|
|
err = r.ociSpec.Modify(r.addNVIDIAHook)
|
|
if err != nil {
|
|
return fmt.Errorf("error injecting NVIDIA Container Runtime hook: %v", err)
|
|
}
|
|
|
|
err = r.ociSpec.Flush()
|
|
if err != nil {
|
|
return fmt.Errorf("error writing modified OCI specification: %v", err)
|
|
}
|
|
return nil
|
|
}
|
|
|
|
// addNVIDIAHook modifies the specified OCI specification in-place, inserting a
|
|
// prestart hook.
|
|
func (r nvidiaContainerRuntime) addNVIDIAHook(spec *specs.Spec) error {
|
|
path, err := exec.LookPath("nvidia-container-runtime-hook")
|
|
if err != nil {
|
|
path = hookDefaultFilePath
|
|
_, err = os.Stat(path)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
}
|
|
|
|
r.logger.Printf("prestart hook path: %s\n", path)
|
|
|
|
args := []string{path}
|
|
if spec.Hooks == nil {
|
|
spec.Hooks = &specs.Hooks{}
|
|
} else if len(spec.Hooks.Prestart) != 0 {
|
|
for _, hook := range spec.Hooks.Prestart {
|
|
if !strings.Contains(hook.Path, "nvidia-container-runtime-hook") {
|
|
continue
|
|
}
|
|
r.logger.Println("existing nvidia prestart hook in OCI spec file")
|
|
return nil
|
|
}
|
|
}
|
|
|
|
spec.Hooks.Prestart = append(spec.Hooks.Prestart, specs.Hook{
|
|
Path: path,
|
|
Args: append(args, "prestart"),
|
|
})
|
|
|
|
return nil
|
|
}
|