144 lines
3.7 KiB
Go
144 lines
3.7 KiB
Go
// Copyright 2015 CNI authors
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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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package disk
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import (
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"io/ioutil"
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"net"
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"os"
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"path/filepath"
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"strings"
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"github.com/containernetworking/plugins/plugins/ipam/host-local/backend"
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"runtime"
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)
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const lastIPFilePrefix = "last_reserved_ip."
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const LineBreak = "\r\n"
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var defaultDataDir = "/var/lib/cni/networks"
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// Store is a simple disk-backed store that creates one file per IP
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// address in a given directory. The contents of the file are the container ID.
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type Store struct {
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*FileLock
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dataDir string
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}
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// Store implements the Store interface
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var _ backend.Store = &Store{}
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func New(network, dataDir string) (*Store, error) {
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if dataDir == "" {
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dataDir = defaultDataDir
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}
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dir := filepath.Join(dataDir, network)
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if err := os.MkdirAll(dir, 0755); err != nil {
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return nil, err
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}
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lk, err := NewFileLock(dir)
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if err != nil {
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return nil, err
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}
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return &Store{lk, dir}, nil
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}
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func (s *Store) Reserve(id string, ifname string, ip net.IP, rangeID string) (bool, error) {
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fname := GetEscapedPath(s.dataDir, ip.String())
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f, err := os.OpenFile(fname, os.O_RDWR|os.O_EXCL|os.O_CREATE, 0644)
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if os.IsExist(err) {
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return false, nil
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}
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if err != nil {
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return false, err
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}
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if _, err := f.WriteString(strings.TrimSpace(id) + LineBreak + ifname); err != nil {
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f.Close()
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os.Remove(f.Name())
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return false, err
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}
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if err := f.Close(); err != nil {
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os.Remove(f.Name())
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return false, err
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}
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// store the reserved ip in lastIPFile
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ipfile := GetEscapedPath(s.dataDir, lastIPFilePrefix+rangeID)
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err = ioutil.WriteFile(ipfile, []byte(ip.String()), 0644)
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if err != nil {
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return false, err
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}
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return true, nil
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}
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// LastReservedIP returns the last reserved IP if exists
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func (s *Store) LastReservedIP(rangeID string) (net.IP, error) {
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ipfile := GetEscapedPath(s.dataDir, lastIPFilePrefix+rangeID)
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data, err := ioutil.ReadFile(ipfile)
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if err != nil {
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return nil, err
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}
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return net.ParseIP(string(data)), nil
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}
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func (s *Store) Release(ip net.IP) error {
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return os.Remove(GetEscapedPath(s.dataDir, ip.String()))
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}
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func (s *Store) ReleaseByKey(id string, ifname string, match string) (bool, error) {
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found := false
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err := filepath.Walk(s.dataDir, func(path string, info os.FileInfo, err error) error {
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if err != nil || info.IsDir() {
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return nil
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}
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data, err := ioutil.ReadFile(path)
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if err != nil {
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return nil
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}
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if strings.TrimSpace(string(data)) == match {
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if err := os.Remove(path); err != nil {
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return nil
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}
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found = true
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}
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return nil
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})
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return found, err
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}
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// N.B. This function eats errors to be tolerant and
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// release as much as possible
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func (s *Store) ReleaseByID(id string, ifname string) error {
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found := false
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match := strings.TrimSpace(id) + LineBreak + ifname
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found, err := s.ReleaseByKey(id, ifname, match)
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// For backwards compatibility, look for files written by a previous version
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if !found && err == nil {
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match := strings.TrimSpace(id)
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found, err = s.ReleaseByKey(id, ifname, match)
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}
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return err
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}
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func GetEscapedPath(dataDir string, fname string) string {
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if runtime.GOOS == "windows" {
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fname = strings.Replace(fname, ":", "_", -1)
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}
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return filepath.Join(dataDir, fname)
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}
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