2445a960a9
This changes the ip allocation logic to round robin. Before this, host-local IPAM searched for available IPs from start of subnet. Hence it tends to allocate IPs that had been used recently. This is not ideal since it may cause collisions.
108 lines
2.6 KiB
Go
108 lines
2.6 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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"fmt"
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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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)
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const lastIPFile = "last_reserved_ip"
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var defaultDataDir = "/var/lib/cni/networks"
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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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func New(network string) (*Store, error) {
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dir := filepath.Join(defaultDataDir, network)
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if err := os.MkdirAll(dir, 0644); 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, ip net.IP) (bool, error) {
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fname := filepath.Join(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(id); 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 := filepath.Join(s.dataDir, lastIPFile)
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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() (net.IP, error) {
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ipfile := filepath.Join(s.dataDir, lastIPFile)
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data, err := ioutil.ReadFile(ipfile)
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if err != nil {
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return nil, fmt.Errorf("Failed to retrieve last reserved ip: %v", 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(filepath.Join(s.dataDir, ip.String()))
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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) error {
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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 string(data) == id {
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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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}
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return nil
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})
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return err
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}
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