instancecreds_windows.go

//go:build windows

// 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 instancecreds

import (
	"fmt"

	"github.com/aws/amazon-ecs-agent/ecs-agent/credentials/providers"
	"github.com/aws/amazon-ecs-agent/ecs-agent/logger"

	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/aws/aws-sdk-go/aws/defaults"
)

// GetCredentials returns the instance credentials chain. This is the default chain
// credentials plus the "rotating shared credentials provider", so credentials will
// be checked in this order:
//
//  1. Env vars (AWS_ACCESS_KEY_ID, AWS_SECRET_ACCESS_KEY).
//
//  2. Shared credentials file (https://docs.aws.amazon.com/ses/latest/DeveloperGuide/create-shared-credentials-file.html) (file at ~/.aws/credentials containing access key id and secret access key).
//
//  3. EC2 role credentials. This is an IAM role that the user specifies when they launch their EC2 container instance (ie ecsInstanceRole (https://docs.aws.amazon.com/AmazonECS/latest/developerguide/instance_IAM_role.html)).
//
//  4. Rotating shared credentials file located at /rotatingcreds/credentials
//
//     The default credential chain provided by the SDK includes:
//     * EnvProvider
//     * SharedCredentialsProvider
//     * RemoteCredProvider (EC2RoleProvider)
//
//     In the case of ECS-A on Windows, the `SharedCredentialsProvider` takes
//     precedence over the `RotatingSharedCredentialsProvider` and this results
//     in the credentials not being refreshed. To mitigate this issue, we will
//     reorder the credential chain and ensure that `RotatingSharedCredentialsProvider`
//     takes precedence over the `SharedCredentialsProvider` for ECS-A.
func GetCredentials(isExternal bool) *credentials.Credentials {
	mu.Lock()
	credProviders := defaults.CredProviders(defaults.Config(), defaults.Handlers())
	if isExternal {
		credProviders = append(credProviders[:1], append([]credentials.Provider{providers.NewRotatingSharedCredentialsProvider()}, credProviders[1:]...)...)
	} else {
		credProviders = append(credProviders, providers.NewRotatingSharedCredentialsProvider())
	}
	credentialChain = credentials.NewCredentials(&credentials.ChainProvider{
		VerboseErrors: false,
		Providers:     credProviders,
	})
	mu.Unlock()

	// credentials.Credentials is concurrency-safe, so lock not needed here
	v, err := credentialChain.Get()
	if err != nil {
		logger.Error(fmt.Sprintf("Error getting ECS instance credentials from default chain: %s", err))
	} else {
		logger.Info(fmt.Sprintf("Successfully got ECS instance credentials from provider: %s", v.ProviderName))
	}
	return credentialChain
}