Add ECSClientFactory to create new ECS clients

agent/app/agent.go

@@ -295,8 +295,9 @@ func (agent *ecsAgent) start() int {
 		})
 		return exitcodes.ExitError
 	}
-	client, err := ecsclient.NewECSClient(agent.credentialProvider, cfgAccessor, agent.ec2MetadataClient,
+	clientFactory := ecsclient.NewECSClientFactory(agent.credentialProvider, cfgAccessor, agent.ec2MetadataClient,
 		version.String(), ecsclient.WithIPv6PortBindingExcluded(true))
+	client, err := clientFactory.NewClient()
 	if err != nil {
 		logger.Critical("Unable to create new ECS client", logger.Fields{
 			field.Error: err,

ecs-agent/api/ecs/client/ecs_client_factory.go

@@ -0,0 +1,61 @@
+// Copyright Amazon.com Inc. or its affiliates. All Rights Reserved.
+//
+// Licensed under the Apache License, Version 2.0 (the "License"). You may
+// not use this file except in compliance with the License. A copy of the
+// License is located at
+//
+//	http://aws.amazon.com/apache2.0/
+//
+// or in the "license" file accompanying this file. This file is distributed
+// on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either
+// express or implied. See the License for the specific language governing
+// permissions and limitations under the License.
+
+package ecsclient
+
+import (
+	"github.com/aws/amazon-ecs-agent/ecs-agent/api/ecs"
+	"github.com/aws/amazon-ecs-agent/ecs-agent/config"
+	"github.com/aws/amazon-ecs-agent/ecs-agent/ec2"
+	"github.com/aws/aws-sdk-go/aws/credentials"
+)
+
+// ECSClientFactory interface can be used to create new ECS clients.
+// It wraps the internal ecsClientFactory and can help ease writing unit test code for consumers.
+type ECSClientFactory interface {
+	// NewClient creates a new ECS client.
+	NewClient() (ecs.ECSClient, error)
+	// Credentials returns the credentials chain used by the ECS client.
+	Credentials() *credentials.Credentials
+}
+
+type ecsClientFactory struct {
+	credentialsProvider *credentials.Credentials
+	configAccessor      config.AgentConfigAccessor
+	ec2MetadataClient   ec2.EC2MetadataClient
+	agentVer            string
+	options             []ECSClientOption
+}
+
+func NewECSClientFactory(
+	credentialsProvider *credentials.Credentials,
+	configAccessor config.AgentConfigAccessor,
+	ec2MetadataClient ec2.EC2MetadataClient,
+	agentVer string,
+	options ...ECSClientOption) ECSClientFactory {
+	return &ecsClientFactory{
+		credentialsProvider: credentialsProvider,
+		configAccessor:      configAccessor,
+		ec2MetadataClient:   ec2MetadataClient,
+		agentVer:            agentVer,
+		options:             options,
+	}
+}
+
+func (f *ecsClientFactory) NewClient() (ecs.ECSClient, error) {
+	return NewECSClient(f.credentialsProvider, f.configAccessor, f.ec2MetadataClient, f.agentVer, f.options...)
+}
+
+func (f *ecsClientFactory) Credentials() *credentials.Credentials {
+	return f.credentialsProvider
+}