service/ec2: Fix max retries with client customizations

Fixes #3374 by correcting the EC2 API client's customization for
ModifyNetworkInterfaceAttribute and AssignPrivateIpAddresses operations
to use the aws.Config.MaxRetries value if set. Previously the API client's
customizations would ignore MaxRetries specified in the SDK's
aws.Config.MaxRetries field.

service/ec2/customizations.go

@@ -26,8 +26,12 @@ func init() {
 
 		// only set the retryer on request if config doesn't have a retryer
 		if r.Config.Retryer == nil && (r.Operation.Name == opModifyNetworkInterfaceAttribute || r.Operation.Name == opAssignPrivateIpAddresses) {
+			maxRetries := client.DefaultRetryerMaxNumRetries
+			if m := r.Config.MaxRetries; m != nil && *m != aws.UseServiceDefaultRetries {
+				maxRetries = *m
+			}
 			r.Retryer = client.DefaultRetryer{
-				NumMaxRetries:    client.DefaultRetryerMaxNumRetries,
+				NumMaxRetries:    maxRetries,
 				MinRetryDelay:    customRetryerMinRetryDelay,
 				MinThrottleDelay: customRetryerMinRetryDelay,
 				MaxRetryDelay:    customRetryerMaxRetryDelay,

service/ec2/customizations_test.go

@@ -1,12 +1,17 @@
 package ec2_test
 
 import (
+	"bytes"
+	"context"
 	"io/ioutil"
+	"net/http"
 	"net/url"
 	"regexp"
 	"testing"
 
 	"github.com/aws/aws-sdk-go/aws"
+	sdkclient "github.com/aws/aws-sdk-go/aws/client"
+	"github.com/aws/aws-sdk-go/aws/request"
 	"github.com/aws/aws-sdk-go/awstesting/unit"
 	"github.com/aws/aws-sdk-go/service/ec2"
 )
@@ -46,3 +51,55 @@ func TestCopySnapshotPresignedURL(t *testing.T) {
 		t.Errorf("expect %v to match, got %v", r.String(), u)
 	}
 }
+
+func TestNoCustomRetryerWithMaxRetries(t *testing.T) {
+	cases := map[string]struct {
+		Config           aws.Config
+		ExpectMaxRetries int
+	}{
+		"With custom retrier": {
+			Config: aws.Config{
+				Retryer: sdkclient.DefaultRetryer{
+					NumMaxRetries: 10,
+				},
+			},
+			ExpectMaxRetries: 10,
+		},
+		"with max retries": {
+			Config: aws.Config{
+				MaxRetries: aws.Int(10),
+			},
+			ExpectMaxRetries: 10,
+		},
+		"no options set": {
+			ExpectMaxRetries: sdkclient.DefaultRetryerMaxNumRetries,
+		},
+	}
+
+	for name, c := range cases {
+		t.Run(name, func(t *testing.T) {
+			client := ec2.New(unit.Session, &aws.Config{
+				DisableParamValidation: aws.Bool(true),
+			}, c.Config.Copy())
+			client.ModifyNetworkInterfaceAttributeWithContext(context.Background(), nil, checkRetryerMaxRetries(t, c.ExpectMaxRetries))
+			client.AssignPrivateIpAddressesWithContext(context.Background(), nil, checkRetryerMaxRetries(t, c.ExpectMaxRetries))
+		})
+	}
+
+}
+
+func checkRetryerMaxRetries(t *testing.T, maxRetries int) func(*request.Request) {
+	return func(r *request.Request) {
+		r.Handlers.Send.Clear()
+		r.Handlers.Send.PushBack(func(rr *request.Request) {
+			if e, a := maxRetries, rr.Retryer.MaxRetries(); e != a {
+				t.Errorf("%s, expect %v max retries, got %v", rr.Operation.Name, e, a)
+			}
+			rr.HTTPResponse = &http.Response{
+				StatusCode: 200,
+				Header:     http.Header{},
+				Body:       ioutil.NopCloser(&bytes.Buffer{}),
+			}
+		})
+	}
+}