Initial attempt at volumeattach extension
diff --git a/openstack/compute/v2/extensions/volumeattach/doc.go b/openstack/compute/v2/extensions/volumeattach/doc.go
new file mode 100644
index 0000000..22f68d8
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/doc.go
@@ -0,0 +1,3 @@
+// Package volumeattach provides the ability to attach and detach volumes
+// to instances
+package volumeattach
diff --git a/openstack/compute/v2/extensions/volumeattach/fixtures.go b/openstack/compute/v2/extensions/volumeattach/fixtures.go
new file mode 100644
index 0000000..6b08e18
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/fixtures.go
@@ -0,0 +1,139 @@
+// +build fixtures
+
+package volumeattach
+
+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 = `
+{
+  "volumeAttachments": [
+    {
+      "device": "/dev/vdd",
+      "id": "a26887c6-c47b-4654-abb5-dfadf7d3f803",
+      "serverId": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+      "volumeId": "a26887c6-c47b-4654-abb5-dfadf7d3f803"
+    },
+    {
+      "device": "/dev/vdc",
+      "id": "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+      "serverId": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+      "volumeId": "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+    }
+  ]
+}
+`
+
+// GetOutput is a sample response to a Get call.
+const GetOutput = `
+{
+  "volumeAttachment": {
+    "device": "/dev/vdc",
+    "id": "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+    "serverId": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+    "volumeId": "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+  }
+}
+`
+
+// CreateOutput is a sample response to a Create call.
+const CreateOutput = `
+{
+  "volumeAttachment": {
+    "device": "/dev/vdc",
+    "id": "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+    "serverId": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+    "volumeId": "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+  }
+}
+`
+
+// FirstVolumeAttachment is the first result in ListOutput.
+var FirstVolumeAttachment = VolumeAttachment{
+	Device:   "/dev/vdd",
+	ID:       "a26887c6-c47b-4654-abb5-dfadf7d3f803",
+	ServerID: "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+	VolumeID: "a26887c6-c47b-4654-abb5-dfadf7d3f803",
+}
+
+// SecondVolumeAttachment is the first result in ListOutput.
+var SecondVolumeAttachment = VolumeAttachment{
+	Device:   "/dev/vdc",
+	ID:       "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+	ServerID: "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+	VolumeID: "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+}
+
+// ExpectedVolumeAttachmentSlide is the slice of results that should be parsed
+// from ListOutput, in the expected order.
+var ExpectedVolumeAttachmentSlice = []VolumeAttachment{FirstVolumeAttachment, SecondVolumeAttachment}
+
+// CreatedVolumeAttachment is the parsed result from CreatedOutput.
+var CreatedVolumeAttachment = VolumeAttachment{
+	Device:   "/dev/vdc",
+	ID:       "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+	ServerID: "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+	VolumeID: "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+}
+
+// HandleListSuccessfully configures the test server to respond to a List request.
+func HandleListSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/os-volume_attachments", 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 attachment
+func HandleGetSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/os-volume_attachments/a26887c6-c47b-4654-abb5-dfadf7d3f804", 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 attachment
+func HandleCreateSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/os-volume_attachments", 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, `
+{
+  "volumeAttachment": {
+    "volumeId": "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+		"serverId": "4d8c3732-a248-40ed-bebc-539a6ffd25c0",
+    "device": "/dev/vdc"
+  }
+}
+`)
+
+		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 attachment
+func HandleDeleteSuccessfully(t *testing.T) {
+	th.Mux.HandleFunc("/servers/4d8c3732-a248-40ed-bebc-539a6ffd25c0/os-volume_attachments/a26887c6-c47b-4654-abb5-dfadf7d3f804", 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)
+	})
+}
diff --git a/openstack/compute/v2/extensions/volumeattach/requests.go b/openstack/compute/v2/extensions/volumeattach/requests.go
new file mode 100644
index 0000000..ba1b7d4
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/requests.go
@@ -0,0 +1,119 @@
+package volumeattach
+
+import (
+	"errors"
+
+	"github.com/racker/perigee"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/openstack/compute/v2/servers"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// CreateOptsExt adds a VolumeAttachment option to the base CreateOpts.
+type CreateOptsExt struct {
+	servers.CreateOptsBuilder
+	Device   string `json:"device"`
+	VolumeID string `json:"volumeId"`
+	ServerID string `json:"serverId"`
+}
+
+// ToServerCreateMap adds the volume_id, device, and optionally server_id to
+// the base server creation options.
+func (opts CreateOptsExt) ToServerCreateMap() (map[string]interface{}, error) {
+	base, err := opts.CreateOptsBuilder.ToServerCreateMap()
+	if err != nil {
+		return nil, err
+	}
+
+	serverMap := base["server"].(map[string]interface{})
+	serverMap["device"] = opts.Device
+	serverMap["volume_id"] = opts.VolumeID
+	serverMap["server_id"] = opts.ServerID
+
+	return base, nil
+}
+
+// List returns a Pager that allows you to iterate over a collection of VolumeAttachments.
+func List(client *gophercloud.ServiceClient, serverId string) pagination.Pager {
+	return pagination.NewPager(client, listURL(client, serverId), func(r pagination.PageResult) pagination.Page {
+		return VolumeAttachmentsPage{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 {
+	ToVolumeAttachmentCreateMap() (map[string]interface{}, error)
+}
+
+// CreateOpts specifies volume attachment creation or import parameters.
+type CreateOpts struct {
+	// Device is the device that the volume will attach to the instance as. Omit for "auto"
+	Device string
+
+	// VolumeID is the ID of the volume to attach to the instance
+	VolumeID string
+
+	// ServerID is the ID of the server that the volume will be attached to
+	ServerID string
+}
+
+// ToVolumeAttachmentCreateMap constructs a request body from CreateOpts.
+func (opts CreateOpts) ToVolumeAttachmentCreateMap() (map[string]interface{}, error) {
+	if opts.VolumeID == "" {
+		return nil, errors.New("Missing field required for volume attachment creation: VolumeID")
+	}
+
+	if opts.ServerID == "" {
+		return nil, errors.New("Missing field required for volume attachment creation: ServerID")
+	}
+
+	volumeAttachment := make(map[string]interface{})
+	volumeAttachment["volumeId"] = opts.VolumeID
+	volumeAttachment["serverId"] = opts.ServerID
+	if opts.Device != "" {
+		volumeAttachment["device"] = opts.Device
+	}
+
+	return map[string]interface{}{"volumeAttachment": volumeAttachment}, nil
+}
+
+// Create requests the creation of a new volume attachment on the server
+func Create(client *gophercloud.ServiceClient, serverId string, opts CreateOptsBuilder) CreateResult {
+	var res CreateResult
+
+	reqBody, err := opts.ToVolumeAttachmentCreateMap()
+	if err != nil {
+		res.Err = err
+		return res
+	}
+
+	_, res.Err = perigee.Request("POST", createURL(client, serverId), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		ReqBody:     reqBody,
+		Results:     &res.Body,
+		OkCodes:     []int{200},
+	})
+	return res
+}
+
+// Get returns public data about a previously created VolumeAttachment.
+func Get(client *gophercloud.ServiceClient, serverId, aId string) GetResult {
+	var res GetResult
+	_, res.Err = perigee.Request("GET", getURL(client, serverId, aId), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		Results:     &res.Body,
+		OkCodes:     []int{200},
+	})
+	return res
+}
+
+// Delete requests the deletion of a previous stored VolumeAttachment from the server.
+func Delete(client *gophercloud.ServiceClient, serverId, aId string) DeleteResult {
+	var res DeleteResult
+	_, res.Err = perigee.Request("DELETE", deleteURL(client, serverId, aId), perigee.Options{
+		MoreHeaders: client.AuthenticatedHeaders(),
+		OkCodes:     []int{202},
+	})
+	return res
+}
diff --git a/openstack/compute/v2/extensions/volumeattach/requests_test.go b/openstack/compute/v2/extensions/volumeattach/requests_test.go
new file mode 100644
index 0000000..e0d5fdf
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/requests_test.go
@@ -0,0 +1,66 @@
+package volumeattach
+
+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)
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	count := 0
+	err := List(client.ServiceClient(), serverId).EachPage(func(page pagination.Page) (bool, error) {
+		count++
+		actual, err := ExtractVolumeAttachments(page)
+		th.AssertNoErr(t, err)
+		th.CheckDeepEquals(t, ExpectedVolumeAttachmentSlice, 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)
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	actual, err := Create(client.ServiceClient(), serverId, CreateOpts{
+		Device:   "/dev/vdc",
+		VolumeID: "a26887c6-c47b-4654-abb5-dfadf7d3f804",
+		ServerID: serverId,
+	}).Extract()
+	th.AssertNoErr(t, err)
+	th.CheckDeepEquals(t, &CreatedVolumeAttachment, actual)
+}
+
+func TestGet(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleGetSuccessfully(t)
+	aId := "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	actual, err := Get(client.ServiceClient(), serverId, aId).Extract()
+	th.AssertNoErr(t, err)
+	th.CheckDeepEquals(t, &SecondVolumeAttachment, actual)
+}
+
+func TestDelete(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleDeleteSuccessfully(t)
+	aId := "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	err := Delete(client.ServiceClient(), serverId, aId).ExtractErr()
+	th.AssertNoErr(t, err)
+}
diff --git a/openstack/compute/v2/extensions/volumeattach/results.go b/openstack/compute/v2/extensions/volumeattach/results.go
new file mode 100644
index 0000000..26be39e
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/results.go
@@ -0,0 +1,84 @@
+package volumeattach
+
+import (
+	"github.com/mitchellh/mapstructure"
+	"github.com/rackspace/gophercloud"
+	"github.com/rackspace/gophercloud/pagination"
+)
+
+// VolumeAttach controls the attachment of a volume to an instance.
+type VolumeAttachment struct {
+	// ID is a unique id of the attachment
+	ID string `mapstructure:"id"`
+
+	// Device is what device the volume is attached as
+	Device string `mapstructure:"device"`
+
+	// VolumeID is the ID of the attached volume
+	VolumeID string `mapstructure:"volumeId"`
+
+	// ServerID is the ID of the instance that has the volume attached
+	ServerID string `mapstructure:"serverId"`
+}
+
+// VolumeAttachmentsPage stores a single, only page of VolumeAttachments
+// results from a List call.
+type VolumeAttachmentsPage struct {
+	pagination.SinglePageBase
+}
+
+// IsEmpty determines whether or not a VolumeAttachmentsPage is empty.
+func (page VolumeAttachmentsPage) IsEmpty() (bool, error) {
+	va, err := ExtractVolumeAttachments(page)
+	return len(va) == 0, err
+}
+
+// ExtractVolumeAttachments interprets a page of results as a slice of
+// VolumeAttachments.
+func ExtractVolumeAttachments(page pagination.Page) ([]VolumeAttachment, error) {
+	casted := page.(VolumeAttachmentsPage).Body
+	var response struct {
+		VolumeAttachments []VolumeAttachment `mapstructure:"volumeAttachments"`
+	}
+
+	err := mapstructure.WeakDecode(casted, &response)
+
+	return response.VolumeAttachments, err
+}
+
+type VolumeAttachmentResult struct {
+	gophercloud.Result
+}
+
+// Extract is a method that attempts to interpret any VolumeAttachment resource
+// response as a VolumeAttachment struct.
+func (r VolumeAttachmentResult) Extract() (*VolumeAttachment, error) {
+	if r.Err != nil {
+		return nil, r.Err
+	}
+
+	var res struct {
+		VolumeAttachment *VolumeAttachment `json:"volumeAttachment" mapstructure:"volumeAttachment"`
+	}
+
+	err := mapstructure.Decode(r.Body, &res)
+	return res.VolumeAttachment, err
+}
+
+// CreateResult is the response from a Create operation. Call its Extract method to interpret it
+// as a VolumeAttachment.
+type CreateResult struct {
+	VolumeAttachmentResult
+}
+
+// GetResult is the response from a Get operation. Call its Extract method to interpret it
+// as a VolumeAttachment.
+type GetResult struct {
+	VolumeAttachmentResult
+}
+
+// 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
+}
diff --git a/openstack/compute/v2/extensions/volumeattach/urls.go b/openstack/compute/v2/extensions/volumeattach/urls.go
new file mode 100644
index 0000000..9d9d178
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/urls.go
@@ -0,0 +1,25 @@
+package volumeattach
+
+import "github.com/rackspace/gophercloud"
+
+const resourcePath = "os-volume_attachments"
+
+func resourceURL(c *gophercloud.ServiceClient, serverId string) string {
+	return c.ServiceURL("servers", serverId, resourcePath)
+}
+
+func listURL(c *gophercloud.ServiceClient, serverId string) string {
+	return resourceURL(c, serverId)
+}
+
+func createURL(c *gophercloud.ServiceClient, serverId string) string {
+	return resourceURL(c, serverId)
+}
+
+func getURL(c *gophercloud.ServiceClient, serverId, aId string) string {
+	return c.ServiceURL("servers", serverId, resourcePath, aId)
+}
+
+func deleteURL(c *gophercloud.ServiceClient, serverId, aId string) string {
+	return getURL(c, serverId, aId)
+}
diff --git a/openstack/compute/v2/extensions/volumeattach/urls_test.go b/openstack/compute/v2/extensions/volumeattach/urls_test.go
new file mode 100644
index 0000000..8ee0e42
--- /dev/null
+++ b/openstack/compute/v2/extensions/volumeattach/urls_test.go
@@ -0,0 +1,46 @@
+package volumeattach
+
+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()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/os-volume_attachments", listURL(c, serverId))
+}
+
+func TestCreateURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/os-volume_attachments", createURL(c, serverId))
+}
+
+func TestGetURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+	aId := "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/os-volume_attachments/"+aId, getURL(c, serverId, aId))
+}
+
+func TestDeleteURL(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	c := client.ServiceClient()
+	serverId := "4d8c3732-a248-40ed-bebc-539a6ffd25c0"
+	aId := "a26887c6-c47b-4654-abb5-dfadf7d3f804"
+
+	th.CheckEquals(t, c.Endpoint+"servers/"+serverId+"/os-volume_attachments/"+aId, deleteURL(c, serverId, aId))
+}