add CloudWatch Alarm API support

pkg/api/cloudwatch/cloudwatch.go

@@ -31,13 +31,15 @@ type cwRequest struct {
 
 func init() {
 	actionHandlers = map[string]actionHandler{
-		"GetMetricStatistics": handleGetMetricStatistics,
-		"ListMetrics":         handleListMetrics,
-		"DescribeInstances":   handleDescribeInstances,
-		"__GetRegions":        handleGetRegions,
-		"__GetNamespaces":     handleGetNamespaces,
-		"__GetMetrics":        handleGetMetrics,
-		"__GetDimensions":     handleGetDimensions,
+		"GetMetricStatistics":     handleGetMetricStatistics,
+		"ListMetrics":             handleListMetrics,
+		"DescribeAlarmsForMetric": handleDescribeAlarmsForMetric,
+		"DescribeAlarmHistory":    handleDescribeAlarmHistory,
+		"DescribeInstances":       handleDescribeInstances,
+		"__GetRegions":            handleGetRegions,
+		"__GetNamespaces":         handleGetNamespaces,
+		"__GetMetrics":            handleGetMetrics,
+		"__GetDimensions":         handleGetDimensions,
 	}
 }
 
@@ -137,6 +139,70 @@ func handleListMetrics(req *cwRequest, c *middleware.Context) {
 	c.JSON(200, resp)
 }
 
+func handleDescribeAlarmsForMetric(req *cwRequest, c *middleware.Context) {
+	svc := cloudwatch.New(&aws.Config{Region: aws.String(req.Region)})
+	reqParam := &struct {
+		Parameters struct {
+			Namespace  string                  `json:"namespace"`
+			MetricName string                  `json:"metricName"`
+			Dimensions []*cloudwatch.Dimension `json:"dimensions"`
+			Statistic  string                  `json:"statistic"`
+			Period     int64                   `json:"period"`
+		} `json:"parameters"`
+	}{}
+	json.Unmarshal(req.Body, reqParam)
+
+	params := &cloudwatch.DescribeAlarmsForMetricInput{
+		Namespace:  aws.String(reqParam.Parameters.Namespace),
+		MetricName: aws.String(reqParam.Parameters.MetricName),
+		Period:     aws.Int64(reqParam.Parameters.Period),
+	}
+	if len(reqParam.Parameters.Dimensions) != 0 {
+		params.Dimensions = reqParam.Parameters.Dimensions
+	}
+	if reqParam.Parameters.Statistic != "" {
+		params.Statistic = aws.String(reqParam.Parameters.Statistic)
+	}
+
+	resp, err := svc.DescribeAlarmsForMetric(params)
+	if err != nil {
+		c.JsonApiErr(500, "Unable to call AWS API", err)
+		return
+	}
+
+	c.JSON(200, resp)
+}
+
+func handleDescribeAlarmHistory(req *cwRequest, c *middleware.Context) {
+	svc := cloudwatch.New(&aws.Config{Region: aws.String(req.Region)})
+	reqParam := &struct {
+		Parameters struct {
+			AlarmName       string `json:"alarmName"`
+			HistoryItemType string `json:"historyItemType"`
+			StartDate       int64  `json:"startDate"`
+			EndDate         int64  `json:"endDate"`
+		} `json:"parameters"`
+	}{}
+	json.Unmarshal(req.Body, reqParam)
+
+	params := &cloudwatch.DescribeAlarmHistoryInput{
+		AlarmName: aws.String(reqParam.Parameters.AlarmName),
+		StartDate: aws.Time(time.Unix(reqParam.Parameters.StartDate, 0)),
+		EndDate:   aws.Time(time.Unix(reqParam.Parameters.EndDate, 0)),
+	}
+	if reqParam.Parameters.HistoryItemType != "" {
+		params.HistoryItemType = aws.String(reqParam.Parameters.HistoryItemType)
+	}
+
+	resp, err := svc.DescribeAlarmHistory(params)
+	if err != nil {
+		c.JsonApiErr(500, "Unable to call AWS API", err)
+		return
+	}
+
+	c.JSON(200, resp)
+}
+
 func handleDescribeInstances(req *cwRequest, c *middleware.Context) {
 	sess := session.New()
 	creds := credentials.NewChainCredentials(