Support "args" in static and tuning

Support "args" field in JSON config to additional configuration
in static and tuning plugins.

plugins/ipam/static/README.md

@@ -56,3 +56,7 @@ The following [CNI_ARGS](https://github.com/containernetworking/cni/blob/master/
 The plugin also support following [capability argument](https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md).
 
 * `ips`: Pass IP addresses for CNI interface
+
+The following [args conventions](https://github.com/containernetworking/cni/blob/master/CONVENTIONS.md#args-in-network-config) are supported:
+
+* `ips` (array of strings): A list of custom IPs to attempt to allocate, with prefix (e.g. '10.10.0.1/24')

plugins/ipam/static/main.go

@@ -38,6 +38,9 @@ type Net struct {
 	RuntimeConfig struct {
 		IPs []string `json:"ips,omitempty"`
 	} `json:"runtimeConfig,omitempty"`
+	Args *struct {
+		A *IPAMArgs `json:"cni"`
+	} `json:"args"`
 }
 
 type IPAMConfig struct {
@@ -54,6 +57,10 @@ type IPAMEnvArgs struct {
 	GATEWAY types.UnmarshallableString `json:"gateway,omitempty"`
 }
 
+type IPAMArgs struct {
+	IPs []string `json:"ips"`
+}
+
 type Address struct {
 	AddressStr string `json:"address"`
 	Gateway    net.IP `json:"gateway,omitempty"`
@@ -146,6 +153,15 @@ func LoadIPAMConfig(bytes []byte, envArgs string) (*IPAMConfig, string, error) {
 		}
 	}
 
+	// import address from args
+	if n.Args != nil && n.Args.A != nil && len(n.Args.A.IPs) != 0 {
+		// args IP overwrites IP, so clear IPAM Config
+		n.IPAM.Addresses = make([]Address, 0, len(n.Args.A.IPs))
+		for _, addr := range n.Args.A.IPs {
+			n.IPAM.Addresses = append(n.IPAM.Addresses, Address{AddressStr: addr})
+		}
+	}
+
 	if n.IPAM == nil {
 		return nil, "", fmt.Errorf("IPAM config missing 'ipam' key")
 	}

plugins/ipam/static/static_test.go

@@ -334,6 +334,76 @@ var _ = Describe("static Operations", func() {
 		})
 		Expect(err).NotTo(HaveOccurred())
 	})
+
+	It("allocates and releases multiple addresses with ADD/DEL, from args", func() {
+		const ifname string = "eth0"
+		const nspath string = "/some/where"
+
+		conf := `{
+			"cniVersion": "0.3.1",
+			"name": "mynet",
+			"type": "ipvlan",
+			"master": "foo0",
+			"ipam": {
+				"type": "static",
+				"routes": [
+				{ "dst": "0.0.0.0/0", "gw": "10.10.0.254" },
+				{ "dst": "3ffe:ffff:0:01ff::1/64",
+                                  "gw": "3ffe:ffff:0::1" } ],
+				  "dns": {
+					"nameservers" : ["8.8.8.8"],
+					"domain": "example.com",
+					"search": [ "example.com" ]
+			        }
+			},
+			"args": {
+				"cni": {
+					"ips" : ["10.10.0.1/24", "3ffe:ffff:0:01ff::1/64"]
+			        }
+			}
+		}`
+
+		args := &skel.CmdArgs{
+			ContainerID: "dummy",
+			Netns:       nspath,
+			IfName:      ifname,
+			StdinData:   []byte(conf),
+		}
+
+		// Allocate the IP
+		r, raw, err := testutils.CmdAddWithArgs(args, func() error {
+			return cmdAdd(args)
+		})
+		Expect(err).NotTo(HaveOccurred())
+		Expect(strings.Index(string(raw), "\"version\":")).Should(BeNumerically(">", 0))
+
+		result, err := current.GetResult(r)
+		Expect(err).NotTo(HaveOccurred())
+
+		// Gomega is cranky about slices with different caps
+		Expect(*result.IPs[0]).To(Equal(
+			current.IPConfig{
+				Version: "4",
+				Address: mustCIDR("10.10.0.1/24"),
+			}))
+		Expect(*result.IPs[1]).To(Equal(
+			current.IPConfig{
+				Version: "6",
+				Address: mustCIDR("3ffe:ffff:0:01ff::1/64"),
+			},
+		))
+		Expect(len(result.IPs)).To(Equal(2))
+		Expect(result.Routes).To(Equal([]*types.Route{
+			{Dst: mustCIDR("0.0.0.0/0"), GW: net.ParseIP("10.10.0.254")},
+			{Dst: mustCIDR("3ffe:ffff:0:01ff::1/64"), GW: net.ParseIP("3ffe:ffff:0::1")},
+		}))
+
+		// Release the IP
+		err = testutils.CmdDelWithArgs(args, func() error {
+			return cmdDel(args)
+		})
+		Expect(err).NotTo(HaveOccurred())
+	})
 })
 
 func mustCIDR(s string) net.IPNet {