mirror of
https://github.com/k8snetworkplumbingwg/multus-cni.git
synced 2025-04-28 11:36:13 +00:00
dcf92c8e94
This commit changes thin container base image to distroless to simplify container image. It replace old shell script entrypoint to golang implementation and implement multus installer (i.e. copy).
85 lines
2.5 KiB
Go
85 lines
2.5 KiB
Go
// Copyright (c) 2023 Multus Authors
|
|
//
|
|
// 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 cmdutils is the package that contains utilities for multus command
|
|
package cmdutils
|
|
|
|
import (
|
|
"fmt"
|
|
"io"
|
|
"os"
|
|
"path/filepath"
|
|
)
|
|
|
|
// CopyFileAtomic does file copy atomically
|
|
func CopyFileAtomic(srcFilePath, destDir, tempFileName, destFileName string) error {
|
|
tempFilePath := filepath.Join(destDir, tempFileName)
|
|
// check temp filepath and remove old file if exists
|
|
if _, err := os.Stat(tempFilePath); err == nil {
|
|
err = os.Remove(tempFilePath)
|
|
if err != nil {
|
|
return fmt.Errorf("cannot remove old temp file %q: %v", tempFilePath, err)
|
|
}
|
|
}
|
|
|
|
// create temp file
|
|
f, err := os.CreateTemp(destDir, tempFileName)
|
|
defer f.Close()
|
|
if err != nil {
|
|
return fmt.Errorf("cannot create temp file %q in %q: %v", tempFileName, destDir, err)
|
|
}
|
|
|
|
srcFile, err := os.Open(srcFilePath)
|
|
if err != nil {
|
|
return fmt.Errorf("cannot open file %q: %v", srcFilePath, err)
|
|
}
|
|
defer srcFile.Close()
|
|
|
|
// Copy file to tempfile
|
|
_, err = io.Copy(f, srcFile)
|
|
if err != nil {
|
|
f.Close()
|
|
os.Remove(tempFilePath)
|
|
return fmt.Errorf("cannot write data to temp file %q: %v", tempFilePath, err)
|
|
}
|
|
if err := f.Sync(); err != nil {
|
|
return fmt.Errorf("cannot flush temp file %q: %v", tempFilePath, err)
|
|
}
|
|
if err := f.Close(); err != nil {
|
|
return fmt.Errorf("cannot close temp file %q: %v", tempFilePath, err)
|
|
}
|
|
|
|
// change file mode if different
|
|
destFilePath := filepath.Join(destDir, destFileName)
|
|
_, err = os.Stat(destFilePath)
|
|
if err != nil && !os.IsNotExist(err) {
|
|
return err
|
|
}
|
|
srcFileStat, err := os.Stat(srcFilePath)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
|
|
if err := os.Chmod(f.Name(), srcFileStat.Mode()); err != nil {
|
|
return fmt.Errorf("cannot set stat on temp file %q: %v", f.Name(), err)
|
|
}
|
|
|
|
// replace file with tempfile
|
|
if err := os.Rename(f.Name(), destFilePath); err != nil {
|
|
return fmt.Errorf("cannot replace %q with temp file %q: %v", destFilePath, tempFilePath, err)
|
|
}
|
|
|
|
return nil
|
|
}
|