Add support for reading meters

Author: carlpett

openstack/telemetry/v2/meters/fixtures.go

@@ -4,11 +4,11 @@ package meters
 
 import (
 	"fmt"
-	"net/http"
-	"testing"
-
 	th "github.com/rackspace/gophercloud/testhelper"
 	"github.com/rackspace/gophercloud/testhelper/client"
+	"net/http"
+	"testing"
+	"time"
 )
 
 // MeterListBody contains the canned body of a meters.List response.
@@ -119,6 +119,23 @@ var (
 		UserId:     "7ya0f7a33717400b951037d55b929c53",
 	}
 
+	ShowHerp = OldSample{
+		Name:       "instance",
+		Type:       "gauge",
+		Unit:       "instance",
+		Volume:     1.0,
+		MessageId:  "5460acce-4fd6-480d-ab18-9735ec7b1996",
+		ProjectId:  "35b17138-b364-4e6a-a131-8f3099c5be68",
+		ResourceId: "bd9431c1-8d69-4ad3-803a-8d4a6b89fd36",
+		ResourceMetadata: map[string]string{
+			"name1": "value1",
+			"name2": "value2",
+		},
+		Source:    "openstack",
+		Timestamp: time.Date(2013, time.November, 21, 12, 33, 8, 323533000, time.UTC),
+		UserId:    "efd87807-12d2-4b38-9c70-5f5c2ac427ff",
+	}
+
 	// StatisticsHerp is a Statistics struct that should correspond to the first result in *[]Statistics.
 	StatisticsHerp = Statistics{
 		Avg:           4.5,

openstack/telemetry/v2/meters/requests.go

@@ -43,6 +43,51 @@ func List(client *gophercloud.ServiceClient, opts ListOptsBuilder) ListResult {
 	return res
 }
 
+// ShowOptsBuilder allows extensions to add additional parameters to the
+// Show request.
+type ShowOptsBuilder interface {
+	ToShowQuery() (string, error)
+}
+
+// ShowOpts allows the filtering and sorting of collections through
+// the API. Filtering is achieved by passing in struct field values that map to
+// the server attributes you want to see returned.
+type ShowOpts struct {
+	QueryField string `q:"q.field"`
+	QueryOp    string `q:"q.op"`
+	QueryValue string `q:"q.value"`
+
+	// Optional, maximum number of results to return
+	Limit int `q:"limit"`
+}
+
+// ToMeterShowQuery formats a ShowOpts into a query string.
+func (opts ShowOpts) ToShowQuery() (string, error) {
+	q, err := gophercloud.BuildQueryString(opts)
+	if err != nil {
+		return "", err
+	}
+	return q.String(), nil
+}
+
+// Show makes a request against the API to show a specific meter
+func Show(client *gophercloud.ServiceClient, meterName string, opts ShowOptsBuilder) ShowResult {
+	var res ShowResult
+	url := showURL(client, meterName)
+
+	if opts != nil {
+		query, err := opts.ToShowQuery()
+		if err != nil {
+			res.Err = err
+			return res
+		}
+		url += query
+	}
+
+	_, res.Err = client.Get(url, &res.Body, &gophercloud.RequestOpts{})
+	return res
+}
+
 // StatisticsOptsBuilder allows extensions to add additional parameters to the
 // List request.
 type MeterStatisticsOptsBuilder interface {

openstack/telemetry/v2/meters/requests_test.go

@@ -22,6 +22,20 @@ func TestListMeters(t *testing.T) {
 	th.CheckDeepEquals(t, MeterDerp, (list)[1])
 }
 
+func TestShowMeters(t *testing.T) {
+	th.SetupHTTP()
+	defer th.TeardownHTTP()
+	HandleMeterShowSuccessfully(t)
+
+	meters, err := Show(client.ServiceClient(), "instance", ShowOpts{}).Extract()
+	th.AssertNoErr(t, err)
+
+	if len(meters) != 1 {
+		t.Fatalf("Expected 1 meters, got %d", len(meters))
+	}
+	th.CheckDeepEquals(t, ShowHerp, (meters)[0])
+}
+
 func TestMeterStatistics(t *testing.T) {
 	th.SetupHTTP()
 	defer th.TeardownHTTP()

openstack/telemetry/v2/meters/results.go

@@ -2,6 +2,7 @@ package meters
 
 import (
 	"reflect"
+	"time"
 
 	"github.com/mitchellh/mapstructure"
 	"github.com/rackspace/gophercloud"
@@ -18,6 +19,21 @@ type Meter struct {
 	UserId     string `mapstructure:"user_id"`
 }
 
+type OldSample struct {
+	Name             string            `mapstructure:"counter_name"`
+	Type             string            `mapstructure:"counter_type"`
+	Unit             string            `mapstructure:"counter_unit"`
+	Volume           float32           `mapstructure:"counter_volume"`
+	MessageId        string            `mapstructure:"message_id"`
+	ProjectId        string            `mapstructure:"project_id"`
+	RecordedAt       time.Time         `mapstructure:"recorded_at"`
+	ResourceId       string            `mapstructure:"resource_id"`
+	ResourceMetadata map[string]string `mapstructure:"resource_metadata"`
+	Source           string            `mapstructure:"source"`
+	Timestamp        time.Time         `mapstructure:"timestamp"`
+	UserId           string            `mapstructure:"user_id"`
+}
+
 type ListResult struct {
 	gophercloud.Result
 }
@@ -47,6 +63,34 @@ func (r ListResult) Extract() ([]Meter, error) {
 	return response, nil
 }
 
+type ShowResult struct {
+	gophercloud.Result
+}
+
+func (r ShowResult) Extract() ([]OldSample, error) {
+	if r.Err != nil {
+		return nil, r.Err
+	}
+
+	var response []OldSample
+
+	config := &mapstructure.DecoderConfig{
+		DecodeHook: decoderHooks,
+		Result:     &response,
+	}
+	decoder, err := mapstructure.NewDecoder(config)
+	if err != nil {
+		return nil, err
+	}
+
+	err = decoder.Decode(r.Body)
+	if err != nil {
+		return nil, err
+	}
+
+	return response, nil
+}
+
 type Statistics struct {
 	Avg           float32 `json:"avg"`
 	Count         int     `json:"count"`
@@ -91,9 +135,26 @@ func (r StatisticsResult) Extract() ([]Statistics, error) {
 	return response, nil
 }
 
+func decoderHooks(from reflect.Type, to reflect.Type, data interface{}) (interface{}, error) {
+	if (from.Kind() == reflect.String) && (to.Kind() == reflect.Map) {
+		return toMapFromString(from.Kind(), to.Kind(), data)
+	} else if to == reflect.TypeOf(time.Time{}) && from == reflect.TypeOf("") {
+		return toDateFromString(from, to, data)
+	}
+	return data, nil
+}
 func toMapFromString(from reflect.Kind, to reflect.Kind, data interface{}) (interface{}, error) {
 	if (from == reflect.String) && (to == reflect.Map) {
 		return map[string]interface{}{}, nil
 	}
 	return data, nil
 }
+
+// From https://github.com/mitchellh/mapstructure/issues/41
+func toDateFromString(from reflect.Type, to reflect.Type, data interface{}) (interface{}, error) {
+	if to == reflect.TypeOf(time.Time{}) && from == reflect.TypeOf("") {
+		return time.Parse("2006-01-02T15:04:05.999999999", data.(string))
+	}
+
+	return data, nil
+}