host-local: Update host-local IPAM to support Windows

plugins/ipam/host-local/backend/disk/backend.go

@@ -22,6 +22,7 @@ import (
 	"strings"
 
 	"github.com/containernetworking/plugins/plugins/ipam/host-local/backend"
+	"runtime"
 )
 
 const lastIPFilePrefix = "last_reserved_ip."
@@ -55,7 +56,8 @@ func New(network, dataDir string) (*Store, error) {
 }
 
 func (s *Store) Reserve(id string, ip net.IP, rangeID string) (bool, error) {
-	fname := filepath.Join(s.dataDir, ip.String())
+	fname := GetEscapedPath(s.dataDir, ip.String())
+
 	f, err := os.OpenFile(fname, os.O_RDWR|os.O_EXCL|os.O_CREATE, 0644)
 	if os.IsExist(err) {
 		return false, nil
@@ -73,7 +75,7 @@ func (s *Store) Reserve(id string, ip net.IP, rangeID string) (bool, error) {
 		return false, err
 	}
 	// store the reserved ip in lastIPFile
-	ipfile := filepath.Join(s.dataDir, lastIPFilePrefix+rangeID)
+	ipfile := GetEscapedPath(s.dataDir, lastIPFilePrefix+rangeID)
 	err = ioutil.WriteFile(ipfile, []byte(ip.String()), 0644)
 	if err != nil {
 		return false, err
@@ -83,7 +85,7 @@ func (s *Store) Reserve(id string, ip net.IP, rangeID string) (bool, error) {
 
 // LastReservedIP returns the last reserved IP if exists
 func (s *Store) LastReservedIP(rangeID string) (net.IP, error) {
-	ipfile := filepath.Join(s.dataDir, lastIPFilePrefix+rangeID)
+	ipfile := GetEscapedPath(s.dataDir, lastIPFilePrefix+rangeID)
 	data, err := ioutil.ReadFile(ipfile)
 	if err != nil {
 		return nil, err
@@ -92,7 +94,7 @@ func (s *Store) LastReservedIP(rangeID string) (net.IP, error) {
 }
 
 func (s *Store) Release(ip net.IP) error {
-	return os.Remove(filepath.Join(s.dataDir, ip.String()))
+	return os.Remove(GetEscapedPath(s.dataDir, ip.String()))
 }
 
 // N.B. This function eats errors to be tolerant and
@@ -115,3 +117,10 @@ func (s *Store) ReleaseByID(id string) error {
 	})
 	return err
 }
+
+func GetEscapedPath(dataDir string, fname string) string {
+	if runtime.GOOS == "windows" {
+		fname = strings.Replace(fname, ":", "_", -1)
+	}
+	return filepath.Join(dataDir, fname)
+}

plugins/ipam/host-local/backend/disk/disk_suite_test.go

@@ -0,0 +1,27 @@
+// Copyright 2016 CNI 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 disk
+
+import (
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+
+	"testing"
+)
+
+func TestLock(t *testing.T) {
+	RegisterFailHandler(Fail)
+	RunSpecs(t, "Disk Suite")
+}

plugins/ipam/host-local/backend/disk/lock.go

@@ -1,4 +1,3 @@
-// +build !windows
 // Copyright 2015 CNI authors
 //
 // Licensed under the Apache License, Version 2.0 (the "License");
@@ -16,36 +15,45 @@
 package disk
 
 import (
+	"github.com/alexflint/go-filemutex"
 	"os"
-	"syscall"
+	"path"
 )
 
 // FileLock wraps os.File to be used as a lock using flock
 type FileLock struct {
-	f *os.File
+	f *filemutex.FileMutex
 }
 
 // NewFileLock opens file/dir at path and returns unlocked FileLock object
-func NewFileLock(path string) (*FileLock, error) {
-	f, err := os.Open(path)
+func NewFileLock(lockPath string) (*FileLock, error) {
+	fi, err := os.Stat(lockPath)
+	if err != nil {
+		return nil, err
+	}
+
+	if fi.IsDir() {
+		lockPath = path.Join(lockPath, "lock")
+	}
+
+	f, err := filemutex.New(lockPath)
 	if err != nil {
 		return nil, err
 	}
 
 	return &FileLock{f}, nil
 }
 
-// Close closes underlying file
 func (l *FileLock) Close() error {
 	return l.f.Close()
 }
 
 // Lock acquires an exclusive lock
 func (l *FileLock) Lock() error {
-	return syscall.Flock(int(l.f.Fd()), syscall.LOCK_EX)
+	return l.f.Lock()
 }
 
 // Unlock releases the lock
 func (l *FileLock) Unlock() error {
-	return syscall.Flock(int(l.f.Fd()), syscall.LOCK_UN)
+	return l.f.Unlock()
 }

plugins/ipam/host-local/backend/disk/lock_test.go

@@ -0,0 +1,63 @@
+// Copyright 2016 CNI 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 disk
+
+import (
+	"io/ioutil"
+	"os"
+	"path/filepath"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("Lock Operations", func() {
+	It("locks a file path", func() {
+		dir, err := ioutil.TempDir("", "")
+		Expect(err).ToNot(HaveOccurred())
+		defer os.RemoveAll(dir)
+
+		// create a dummy file to lock
+		path := filepath.Join(dir, "x")
+		f, err := os.OpenFile(path, os.O_RDONLY|os.O_CREATE, 0666)
+		Expect(err).ToNot(HaveOccurred())
+		err = f.Close()
+		Expect(err).ToNot(HaveOccurred())
+
+		// now use it to lock
+		m, err := NewFileLock(path)
+		Expect(err).ToNot(HaveOccurred())
+
+		err = m.Lock()
+		Expect(err).ToNot(HaveOccurred())
+		err = m.Unlock()
+		Expect(err).ToNot(HaveOccurred())
+	})
+
+	It("locks a folder path", func() {
+		dir, err := ioutil.TempDir("", "")
+		Expect(err).ToNot(HaveOccurred())
+		defer os.RemoveAll(dir)
+
+		// use the folder to lock
+		m, err := NewFileLock(dir)
+		Expect(err).ToNot(HaveOccurred())
+
+		err = m.Lock()
+		Expect(err).ToNot(HaveOccurred())
+		err = m.Unlock()
+		Expect(err).ToNot(HaveOccurred())
+	})
+})