fix EC2RoleProvider parameter

pkg/api/cloudwatch/cloudwatch.go

@@ -140,11 +140,12 @@ func handleListMetrics(req *cwRequest, c *middleware.Context) {
 }
 
 func handleDescribeAlarmsForMetric(req *cwRequest, c *middleware.Context) {
+	sess := session.New()
 	creds := credentials.NewChainCredentials(
 		[]credentials.Provider{
 			&credentials.EnvProvider{},
 			&credentials.SharedCredentialsProvider{Filename: "", Profile: req.DataSource.Database},
-			&ec2rolecreds.EC2RoleProvider{ExpiryWindow: 5 * time.Minute},
+			&ec2rolecreds.EC2RoleProvider{Client: ec2metadata.New(sess), ExpiryWindow: 5 * time.Minute},
 		})
 
 	cfg := &aws.Config{
@@ -187,11 +188,12 @@ func handleDescribeAlarmsForMetric(req *cwRequest, c *middleware.Context) {
 }
 
 func handleDescribeAlarmHistory(req *cwRequest, c *middleware.Context) {
+	sess := session.New()
 	creds := credentials.NewChainCredentials(
 		[]credentials.Provider{
 			&credentials.EnvProvider{},
 			&credentials.SharedCredentialsProvider{Filename: "", Profile: req.DataSource.Database},
-			&ec2rolecreds.EC2RoleProvider{ExpiryWindow: 5 * time.Minute},
+			&ec2rolecreds.EC2RoleProvider{Client: ec2metadata.New(sess), ExpiryWindow: 5 * time.Minute},
 		})
 
 	cfg := &aws.Config{