host-local: trim whitespace from container IDs and disk file contents

It doesn't seem like container IDs should really have whitespace or
newlines in them.  As a complete edge-case, manipulating the host-local
store's IP reservations with 'echo' puts a newline at the end, which
caused matching to fail in ReleaseByID().  Don't ask...

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

@@ -20,6 +20,7 @@ import (
 	"net"
 	"os"
 	"path/filepath"
+	"strings"
 )
 
 const lastIPFile = "last_reserved_ip"
@@ -56,7 +57,7 @@ func (s *Store) Reserve(id string, ip net.IP) (bool, error) {
 	if err != nil {
 		return false, err
 	}
-	if _, err := f.WriteString(id); err != nil {
+	if _, err := f.WriteString(strings.TrimSpace(id)); err != nil {
 		f.Close()
 		os.Remove(f.Name())
 		return false, err
@@ -99,7 +100,7 @@ func (s *Store) ReleaseByID(id string) error {
 		if err != nil {
 			return nil
 		}
-		if string(data) == id {
+		if strings.TrimSpace(string(data)) == strings.TrimSpace(id) {
 			if err := os.Remove(path); err != nil {
 				return nil
 			}

plugins/ipam/host-local/host_local_test.go

@@ -89,4 +89,52 @@ var _ = Describe("host-local Operations", func() {
 		_, err = os.Stat(ipFilePath)
 		Expect(err).To(HaveOccurred())
 	})
+
+	It("ignores whitespace in disk files", func() {
+		const ifname string = "eth0"
+		const nspath string = "/some/where"
+
+		tmpDir, err := ioutil.TempDir("", "host_local_artifacts")
+		Expect(err).NotTo(HaveOccurred())
+		defer os.RemoveAll(tmpDir)
+
+		conf := fmt.Sprintf(`{
+    "cniVersion": "0.2.0",
+    "name": "mynet",
+    "type": "ipvlan",
+    "master": "foo0",
+    "ipam": {
+        "type": "host-local",
+        "subnet": "10.1.2.0/24",
+        "dataDir": "%s"
+    }
+}`, tmpDir)
+
+		args := &skel.CmdArgs{
+			ContainerID: "   dummy\n ",
+			Netns:       nspath,
+			IfName:      ifname,
+			StdinData:   []byte(conf),
+		}
+
+		// Allocate the IP
+		result, err := testutils.CmdAddWithResult(nspath, ifname, func() error {
+			return cmdAdd(args)
+		})
+		Expect(err).NotTo(HaveOccurred())
+
+		ipFilePath := filepath.Join(tmpDir, "mynet", result.IP4.IP.IP.String())
+		contents, err := ioutil.ReadFile(ipFilePath)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(string(contents)).To(Equal("dummy"))
+
+		// Release the IP
+		err = testutils.CmdDelWithResult(nspath, ifname, func() error {
+			return cmdDel(args)
+		})
+		Expect(err).NotTo(HaveOccurred())
+
+		_, err = os.Stat(ipFilePath)
+		Expect(err).To(HaveOccurred())
+	})
 })