host-local: add DataDir IPAM conf option and use it for testcases

Add an e2e host-local plugin testcase, which requires being able
to pass the datadir into the plugin so we can erase it later.
We're not always guaranteed to have access to the default data
dir location, plus it should probably be configurable anyway.

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

@@ -31,8 +31,11 @@ type Store struct {
 	dataDir string
 }
 
-func New(network string) (*Store, error) {
-	dir := filepath.Join(defaultDataDir, network)
+func New(network, dataDir string) (*Store, error) {
+	if dataDir == "" {
+		dataDir = defaultDataDir
+	}
+	dir := filepath.Join(dataDir, network)
 	if err := os.MkdirAll(dir, 0644); err != nil {
 		return nil, err
 	}

plugins/ipam/host-local/config.go

@@ -31,6 +31,7 @@ type IPAMConfig struct {
 	Subnet     types.IPNet   `json:"subnet"`
 	Gateway    net.IP        `json:"gateway"`
 	Routes     []types.Route `json:"routes"`
+	DataDir    string        `json:"dataDir"`
 	Args       *IPAMArgs     `json:"-"`
 }
 

plugins/ipam/host-local/host_local_test.go

@@ -0,0 +1,92 @@
+// 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 main
+
+import (
+	"fmt"
+	"io/ioutil"
+	"net"
+	"os"
+	"path/filepath"
+
+	"github.com/containernetworking/cni/pkg/skel"
+	"github.com/containernetworking/cni/pkg/testutils"
+	"github.com/containernetworking/cni/pkg/types"
+
+	. "github.com/onsi/ginkgo"
+	. "github.com/onsi/gomega"
+)
+
+var _ = Describe("host-local Operations", func() {
+	It("allocates and releases an address with ADD/DEL", 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",
+			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())
+
+		expectedAddress, err := types.ParseCIDR("10.1.2.2/24")
+		Expect(err).NotTo(HaveOccurred())
+		expectedAddress.IP = expectedAddress.IP.To16()
+		Expect(result.IP4.IP).To(Equal(*expectedAddress))
+
+		Expect(result.IP4.Gateway).To(Equal(net.ParseIP("10.1.2.1")))
+
+		ipFilePath := filepath.Join(tmpDir, "mynet", "10.1.2.2")
+		contents, err := ioutil.ReadFile(ipFilePath)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(string(contents)).To(Equal("dummy"))
+
+		lastFilePath := filepath.Join(tmpDir, "mynet", "last_reserved_ip")
+		contents, err = ioutil.ReadFile(lastFilePath)
+		Expect(err).NotTo(HaveOccurred())
+		Expect(string(contents)).To(Equal("10.1.2.2"))
+
+		// 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())
+	})
+})

plugins/ipam/host-local/main.go

@@ -32,7 +32,7 @@ func cmdAdd(args *skel.CmdArgs) error {
 		return err
 	}
 
-	store, err := disk.New(ipamConf.Name)
+	store, err := disk.New(ipamConf.Name, ipamConf.DataDir)
 	if err != nil {
 		return err
 	}
@@ -60,7 +60,7 @@ func cmdDel(args *skel.CmdArgs) error {
 		return err
 	}
 
-	store, err := disk.New(ipamConf.Name)
+	store, err := disk.New(ipamConf.Name, ipamConf.DataDir)
 	if err != nil {
 		return err
 	}