Added support for os-floating-ips extension

This commit adds support for the os-floating-ips extention. This allows
users to allocate and deallocate floating IPs as well as have instances
associate and disassociate floating IPs in a nova-network based cloud.
diff --git a/openstack/compute/v2/extensions/floatingip/doc.go b/openstack/compute/v2/extensions/floatingip/doc.go
new file mode 100644
index 0000000..f74f58c
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/doc.go
@@ -0,0 +1,3 @@
+// Package floatingip provides the ability to manage floating ips through
+// nova-network
+package floatingip
diff --git a/openstack/compute/v2/extensions/floatingip/fixtures.go b/openstack/compute/v2/extensions/floatingip/fixtures.go
new file mode 100644
index 0000000..26f3299
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/fixtures.go
@@ -0,0 +1,174 @@
+// +build fixtures
+
+package floatingip
+
+import (
+	"fmt"
+	"net/http"
+	"testing"
+
+	th "github.com/rackspace/gophercloud/testhelper"
+	"github.com/rackspace/gophercloud/testhelper/client"
+)
+
+// ListOutput is a sample response to a List call.
+const ListOutput = `
+{
+    "floating_ips": [
+        {
+            "fixed_ip": null,
+            "id": 1,
+            "instance_id": null,
+            "ip": "10.10.10.1",
+            "pool": "nova"
+        },
+        {
+            "fixed_ip": "166.78.185.201",
+            "id": 2,
+            "instance_id": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+            "ip": "10.10.10.2",
+            "pool": "nova"
+        }
+    ]
+}
+`
+
+// GetOutput is a sample response to a Get call.
+const GetOutput = `
+{
+    "floating_ip": {
+        "fixed_ip": "166.78.185.201",
+        "id": 2,
+        "instance_id": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+        "ip": "10.10.10.2",
+        "pool": "nova"
+    }
+}
+`
+
+// CreateOutput is a sample response to a Post call
+const CreateOutput = `
+{
+    "floating_ip": {
+        "fixed_ip": null,
+        "id": 1,
+        "instance_id": null,
+        "ip": "10.10.10.1",
+        "pool": "nova"
+    }
+}
+`
+
+// FirstFloatingIP is the first result in ListOutput.
+var FirstFloatingIP = FloatingIP{
+	ID:   "1",
+	IP:   "10.10.10.1",
+	Pool: "nova",
+}
+
+// SecondFloatingIP is the first result in ListOutput.
+var SecondFloatingIP = FloatingIP{
+	FixedIP:    "166.78.185.201",
+	ID:         "2",
+	InstanceID: "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+	IP:         "10.10.10.2",
+	Pool:       "nova",
+}
+
+// ExpectedFloatingIPsSlice is the slice of results that should be parsed
+// from ListOutput, in the expected order.
+var ExpectedFloatingIPsSlice = []FloatingIP{FirstFloatingIP, SecondFloatingIP}
+
+// CreatedFloatingIP is the parsed result from CreateOutput.
+var CreatedFloatingIP = FloatingIP{
+	ID:   "1",
+	IP:   "10.10.10.1",
+	Pool: "nova",
+}
+
+// HandleListSuccessfully configures the test server to respond to a List request.
+func HandleListSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/os-floating-ips", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+		fmt.Fprintf(w, ListOutput)
+	})
+}
+
+// HandleGetSuccessfully configures the test server to respond to a Get request
+// for an existing floating ip
+func HandleGetSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/os-floating-ips/2", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "GET")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+
+		w.Header().Add("Content-Type", "application/json")
+		fmt.Fprintf(w, GetOutput)
+	})
+}
+
+// HandleCreateSuccessfully configures the test server to respond to a Create request
+// for a new floating ip
+func HandleCreateSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/os-floating-ips", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "POST")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+		th.TestJSONRequest(t, r, `
+{
+	"pool": "nova"
+}
+`)
+
+		w.Header().Add("Content-Type", "application/json")
+		fmt.Fprintf(w, CreateOutput)
+	})
+}
+
+// HandleDeleteSuccessfully configures the test server to respond to a Delete request for a
+// an existing floating ip
+func HandleDeleteSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/os-floating-ips/1", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "DELETE")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+
+		w.WriteHeader(http.StatusAccepted)
+	})
+}
+
+// HandleAssociateSuccessfully configures the test server to respond to a Post request
+// to associate an allocated floating IP
+func HandleAssociateSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/action", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "POST")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+		th.TestJSONRequest(t, r, `
+{
+	"addFloatingIp": {
+		"address": "10.10.10.2"
+	}
+}
+`)
+
+		w.WriteHeader(http.StatusAccepted)
+	})
+}
+
+// HandleDisassociateSuccessfully configures the test server to respond to a Post request
+// to disassociate an allocated floating IP
+func HandleDisassociateSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/action", func(w http.ResponseWriter, r *http.Request) {
+		th.TestMethod(t, r, "POST")
+		th.TestHeader(t, r, "X-Auth-Token", client.TokenID)
+		th.TestJSONRequest(t, r, `
+{
+	"removeFloatingIp": {
+		"address": "10.10.10.2"
+	}
+}
+`)
+
+		w.WriteHeader(http.StatusAccepted)
+	})
+}
diff --git a/openstack/compute/v2/extensions/floatingip/requests.go b/openstack/compute/v2/extensions/floatingip/requests.go
new file mode 100644
index 0000000..ab681dc
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/requests.go
@@ -0,0 +1,111 @@
+package floatingip
+
+import (
+	"errors"
+
+	"github.com/racker/perigee"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// List returns a Pager that allows you to iterate over a collection of FloatingIPs.
+func List(client *gophercloud.ServiceClient) pagination.Pager {
+	return pagination.NewPager(client, listURL(client), func(r pagination.PageResult) pagination.Page {
+		return FloatingIPsPage{pagination.SinglePageBase(r)}
+	})
+}
+
+// CreateOptsBuilder describes struct types that can be accepted by the Create call. Notable, the
+// CreateOpts struct in this package does.
+type CreateOptsBuilder interface {
+	ToFloatingIPCreateMap() (map[string]interface{}, error)
+}
+
+// CreateOpts specifies a Floating IP allocation request
+type CreateOpts struct {
+	// Pool is the pool of floating IPs to allocate one from
+	Pool string
+}
+
+// ToFloatingIPCreateMap constructs a request body from CreateOpts.
+func (opts CreateOpts) ToFloatingIPCreateMap() (map[string]interface{}, error) {
+	if opts.Pool == "" {
+		return nil, errors.New("Missing field required for floating IP creation: Pool")
+	}
+
+	return map[string]interface{}{"pool": opts.Pool}, nil
+}
+
+// Create requests the creation of a new floating IP
+func Create(client *gophercloud.ServiceClient, opts CreateOptsBuilder) CreateResult {
+	var res CreateResult
+
+	reqBody, err := opts.ToFloatingIPCreateMap()
+	if err != nil {
+		res.Err = err
+		return res
+	}
+
+	_, res.Err = perigee.Request("POST", createURL(client), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		ReqBody:     reqBody,
+		Results:     &res.Body,
+		OkCodes:     []int{200},
+	})
+	return res
+}
+
+// Get returns data about a previously created FloatingIP.
+func Get(client *gophercloud.ServiceClient, id string) GetResult {
+	var res GetResult
+	_, res.Err = perigee.Request("GET", getURL(client, id), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		Results:     &res.Body,
+		OkCodes:     []int{200},
+	})
+	return res
+}
+
+// Delete requests the deletion of a previous allocated FloatingIP.
+func Delete(client *gophercloud.ServiceClient, id string) DeleteResult {
+	var res DeleteResult
+	_, res.Err = perigee.Request("DELETE", deleteURL(client, id), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		OkCodes:     []int{202},
+	})
+	return res
+}
+
+// association / disassociation
+
+// Associate pairs an allocated floating IP with an instance
+func Associate(client *gophercloud.ServiceClient, serverId, fip string) AssociateResult {
+	var res AssociateResult
+
+	addFloatingIp := make(map[string]interface{})
+	addFloatingIp["address"] = fip
+	reqBody := map[string]interface{}{"addFloatingIp": addFloatingIp}
+
+	_, res.Err = perigee.Request("POST", associateURL(client, serverId), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		ReqBody:     reqBody,
+		OkCodes:     []int{202},
+	})
+	return res
+}
+
+// Disassociate decouples an allocated floating IP from an instance
+func Disassociate(client *gophercloud.ServiceClient, serverId, fip string) DisassociateResult {
+	var res DisassociateResult
+
+	removeFloatingIp := make(map[string]interface{})
+	removeFloatingIp["address"] = fip
+	reqBody := map[string]interface{}{"removeFloatingIp": removeFloatingIp}
+
+	_, res.Err = perigee.Request("POST", disassociateURL(client, serverId), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		ReqBody:     reqBody,
+		OkCodes:     []int{202},
+	})
+	return res
+}
diff --git a/openstack/compute/v2/extensions/floatingip/requests_test.go b/openstack/compute/v2/extensions/floatingip/requests_test.go
new file mode 100644
index 0000000..ed2460e
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/requests_test.go
@@ -0,0 +1,80 @@
+package floatingip
+
+import (
+	"testing"
+
+	"github.com/rackspace/gophercloud/pagination"
+	th "github.com/rackspace/gophercloud/testhelper"
+	"github.com/rackspace/gophercloud/testhelper/client"
+)
+
+func TestList(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleListSuccessfully(t)
+
+	count := 0
+	err := List(client.ServiceClient()).EachPage(func(page pagination.Page) (bool, error) {
+		count++
+		actual, err := ExtractFloatingIPs(page)
+		th.AssertNoErr(t, err)
+		th.CheckDeepEquals(t, ExpectedFloatingIPsSlice, actual)
+
+		return true, nil
+	})
+	th.AssertNoErr(t, err)
+	th.CheckEquals(t, 1, count)
+}
+
+func TestCreate(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleCreateSuccessfully(t)
+
+	actual, err := Create(client.ServiceClient(), CreateOpts{
+		Pool: "nova",
+	}).Extract()
+	th.AssertNoErr(t, err)
+	th.CheckDeepEquals(t, &CreatedFloatingIP, actual)
+}
+
+func TestGet(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleGetSuccessfully(t)
+
+	actual, err := Get(client.ServiceClient(), "2").Extract()
+	th.AssertNoErr(t, err)
+	th.CheckDeepEquals(t, &SecondFloatingIP, actual)
+}
+
+func TestDelete(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleDeleteSuccessfully(t)
+
+	err := Delete(client.ServiceClient(), "1").ExtractErr()
+	th.AssertNoErr(t, err)
+}
+
+func TestAssociate(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleAssociateSuccessfully(t)
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+	fip := "10.10.10.2"
+
+	err := Associate(client.ServiceClient(), serverId, fip).ExtractErr()
+	th.AssertNoErr(t, err)
+}
+
+func TestDisassociate(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleDisassociateSuccessfully(t)
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+	fip := "10.10.10.2"
+
+	err := Disassociate(client.ServiceClient(), serverId, fip).ExtractErr()
+	th.AssertNoErr(t, err)
+}
diff --git a/openstack/compute/v2/extensions/floatingip/results.go b/openstack/compute/v2/extensions/floatingip/results.go
new file mode 100644
index 0000000..be77fa1
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/results.go
@@ -0,0 +1,99 @@
+package floatingip
+
+import (
+	"github.com/mitchellh/mapstructure"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// A FloatingIP is an IP that can be associated with an instance
+type FloatingIP struct {
+	// ID is a unique ID of the Floating IP
+	ID string `mapstructure:"id"`
+
+	// FixedIP is the IP of the instance related to the Floating IP
+	FixedIP string `mapstructure:"fixed_ip,omitempty"`
+
+	// InstanceID is the ID of the instance that is using the Floating IP
+	InstanceID string `mapstructure:"instance_id"`
+
+	// IP is the actual Floating IP
+	IP string `mapstructure:"ip"`
+
+	// Pool is the pool of floating IPs that this floating IP belongs to
+	Pool string `mapstructure:"pool"`
+}
+
+// FloatingIPsPage stores a single, only page of FloatingIPs
+// results from a List call.
+type FloatingIPsPage struct {
+	pagination.SinglePageBase
+}
+
+// IsEmpty determines whether or not a FloatingIPsPage is empty.
+func (page FloatingIPsPage) IsEmpty() (bool, error) {
+	va, err := ExtractFloatingIPs(page)
+	return len(va) == 0, err
+}
+
+// ExtractFloatingIPs interprets a page of results as a slice of
+// FloatingIPs.
+func ExtractFloatingIPs(page pagination.Page) ([]FloatingIP, error) {
+	casted := page.(FloatingIPsPage).Body
+	var response struct {
+		FloatingIPs []FloatingIP `mapstructure:"floating_ips"`
+	}
+
+	err := mapstructure.WeakDecode(casted, &response)
+
+	return response.FloatingIPs, err
+}
+
+type FloatingIPResult struct {
+	gophercloud.Result
+}
+
+// Extract is a method that attempts to interpret any FloatingIP resource
+// response as a FloatingIP struct.
+func (r FloatingIPResult) Extract() (*FloatingIP, error) {
+	if r.Err != nil {
+		return nil, r.Err
+	}
+
+	var res struct {
+		FloatingIP *FloatingIP `json:"floating_ip" mapstructure:"floating_ip"`
+	}
+
+	err := mapstructure.WeakDecode(r.Body, &res)
+	return res.FloatingIP, err
+}
+
+// CreateResult is the response from a Create operation. Call its Extract method to interpret it
+// as a FloatingIP.
+type CreateResult struct {
+	FloatingIPResult
+}
+
+// GetResult is the response from a Get operation. Call its Extract method to interpret it
+// as a FloatingIP.
+type GetResult struct {
+	FloatingIPResult
+}
+
+// DeleteResult is the response from a Delete operation. Call its Extract method to determine if
+// the call succeeded or failed.
+type DeleteResult struct {
+	gophercloud.ErrResult
+}
+
+// AssociateResult is the response from a Delete operation. Call its Extract method to determine if
+// the call succeeded or failed.
+type AssociateResult struct {
+	gophercloud.ErrResult
+}
+
+// DisassociateResult is the response from a Delete operation. Call its Extract method to determine if
+// the call succeeded or failed.
+type DisassociateResult struct {
+	gophercloud.ErrResult
+}
diff --git a/openstack/compute/v2/extensions/floatingip/urls.go b/openstack/compute/v2/extensions/floatingip/urls.go
new file mode 100644
index 0000000..54198f8
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/urls.go
@@ -0,0 +1,37 @@
+package floatingip
+
+import "github.com/rackspace/gophercloud"
+
+const resourcePath = "os-floating-ips"
+
+func resourceURL(c *gophercloud.ServiceClient) string {
+	return c.ServiceURL(resourcePath)
+}
+
+func listURL(c *gophercloud.ServiceClient) string {
+	return resourceURL(c)
+}
+
+func createURL(c *gophercloud.ServiceClient) string {
+	return resourceURL(c)
+}
+
+func getURL(c *gophercloud.ServiceClient, id string) string {
+	return c.ServiceURL(resourcePath, id)
+}
+
+func deleteURL(c *gophercloud.ServiceClient, id string) string {
+	return getURL(c, id)
+}
+
+func serverURL(c *gophercloud.ServiceClient, serverId string) string {
+	return c.ServiceURL("servers/" + serverId + "/action")
+}
+
+func associateURL(c *gophercloud.ServiceClient, serverId string) string {
+	return serverURL(c, serverId)
+}
+
+func disassociateURL(c *gophercloud.ServiceClient, serverId string) string {
+	return serverURL(c, serverId)
+}
diff --git a/openstack/compute/v2/extensions/floatingip/urls_test.go b/openstack/compute/v2/extensions/floatingip/urls_test.go
new file mode 100644
index 0000000..f73d6fb
--- /dev/null
+++ b/openstack/compute/v2/extensions/floatingip/urls_test.go
@@ -0,0 +1,60 @@
+package floatingip
+
+import (
+	"testing"
+
+	th "github.com/rackspace/gophercloud/testhelper"
+	"github.com/rackspace/gophercloud/testhelper/client"
+)
+
+func TestListURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+
+	th.CheckEquals(t, c.Endpoint+"os-floating-ips", listURL(c))
+}
+
+func TestCreateURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+
+	th.CheckEquals(t, c.Endpoint+"os-floating-ips", createURL(c))
+}
+
+func TestGetURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	id := "1"
+
+	th.CheckEquals(t, c.Endpoint+"os-floating-ips/"+id, getURL(c, id))
+}
+
+func TestDeleteURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	id := "1"
+
+	th.CheckEquals(t, c.Endpoint+"os-floating-ips/"+id, deleteURL(c, id))
+}
+
+func TestAssociateURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/action", associateURL(c, serverId))
+}
+
+func TestDisassociateURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/action", disassociateURL(c, serverId))
+}