nvidia-container-toolkit/internal/oci/runtime_low_level.go
Evan Lezar b8acd7657a Import internal/oci package from experimental branch
Signed-off-by: Evan Lezar <elezar@nvidia.com>
2021-10-29 16:44:31 +02:00

62 lines
2.1 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 oci
import (
"fmt"
"os/exec"
log "github.com/sirupsen/logrus"
)
// NewLowLevelRuntime creates a Runtime that wraps a low-level runtime executable.
// The executable specified is taken from the list of supplied candidates, with the first match
// present in the PATH being selected.
func NewLowLevelRuntime(candidates ...string) (Runtime, error) {
return NewLowLevelRuntimeWithLogger(log.StandardLogger(), candidates...)
}
// NewLowLevelRuntimeWithLogger creates a Runtime as with NewLowLevelRuntime using the specified logger.
func NewLowLevelRuntimeWithLogger(logger *log.Logger, candidates ...string) (Runtime, error) {
runtimePath, err := findRuntime(candidates)
if err != nil {
return nil, fmt.Errorf("error locating runtime: %v", err)
}
return NewRuntimeForPathWithLogger(logger, runtimePath)
}
// findRuntime checks elements in a list of supplied candidates for a matching executable in the PATH.
// The absolute path to the first match is returned.
func findRuntime(candidates []string) (string, error) {
if len(candidates) == 0 {
return "", fmt.Errorf("at least one runtime candidate must be specified")
}
for _, candidate := range candidates {
log.Infof("Looking for runtime binary '%v'", candidate)
runcPath, err := exec.LookPath(candidate)
if err == nil {
log.Infof("Found runtime binary '%v'", runcPath)
return runcPath, nil
}
log.Warnf("Runtime binary '%v' not found: %v", candidate, err)
}
return "", fmt.Errorf("no runtime binary found from candidate list: %v", candidates)
}