nvidia-container-toolkit/internal/lookup/file.go
Evan Lezar fd135f1a8b Add Relative function to Locator interface
This adds a Relative function to the Locator interface and uses
this to determine the host and container paths for located files
(and devices). This ensures that the root (e.g. the nvidia driver
root) is stripped from the container path.

Signed-off-by: Evan Lezar <elezar@nvidia.com>
2022-07-01 16:23:50 +02:00

103 lines
2.8 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 lookup
import (
"fmt"
"os"
"path/filepath"
log "github.com/sirupsen/logrus"
)
// file can be used to locate file (or file-like elements) at a specified set of
// prefixes. The validity of a file is determined by a filter function.
type file struct {
logger *log.Logger
root string
prefixes []string
filter func(string) error
}
// NewFileLocator creates a Locator that can be used to find files at the specified root. A logger
// can also be specified.
func NewFileLocator(logger *log.Logger, root string) Locator {
l := newFileLocator(logger, root)
return &l
}
func newFileLocator(logger *log.Logger, root string) file {
return file{
logger: logger,
prefixes: []string{root},
filter: assertFile,
}
}
var _ Locator = (*file)(nil)
// Locate attempts to find files with names matching the specified pattern.
// All prefixes are searched and any matching candidates are returned. If no matches are found, an error is returned.
func (p file) Locate(pattern string) ([]string, error) {
var filenames []string
for _, prefix := range p.prefixes {
pathPattern := filepath.Join(prefix, pattern)
candidates, err := filepath.Glob(pathPattern)
if err != nil {
p.logger.Debugf("Checking pattern '%v' failed: %v", pathPattern, err)
}
for _, candidate := range candidates {
p.logger.Debugf("Checking candidate '%v'", candidate)
err := p.filter(candidate)
if err != nil {
p.logger.Debugf("Candidate '%v' does not meet requirements: %v", candidate, err)
continue
}
filenames = append(filenames, candidate)
}
}
if len(filenames) == 0 {
return nil, fmt.Errorf("pattern %v not found", pattern)
}
return filenames, nil
}
// Relative returns the path relative to the root for the file locator
func (p file) Relative(path string) (string, error) {
if p.root == "" || p.root == "/" {
return path, nil
}
return filepath.Rel(p.root, path)
}
// assertFile checks whether the specified path is a regular file
func assertFile(filename string) error {
info, err := os.Stat(filename)
if err != nil {
return fmt.Errorf("error getting info for %v: %v", filename, err)
}
if info.IsDir() {
return fmt.Errorf("specified path '%v' is a directory", filename)
}
return nil
}