Use RemoteCredProvider instead of EC2RoleProvider

builtin/logical/aws/client.go

@@ -2,6 +2,7 @@ package aws
 
 import (
 	"fmt"
+	"os"
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/session"
@@ -31,7 +32,13 @@ func getRootConfig(s logical.Storage) (*aws.Config, error) {
 	}
 
 	if credsConfig.Region == "" {
-		credsConfig.Region = "us-east-1"
+		credsConfig.Region = os.Getenv("AWS_REGION")
+		if credsConfig.Region == "" {
+			credsConfig.Region = os.Getenv("AWS_DEFAULT_REGION")
+			if credsConfig.Region == "" {
+				credsConfig.Region = "us-east-1"
+			}
+		}
 	}
 
 	credsConfig.HTTPClient = cleanhttp.DefaultClient()

builtin/logical/aws/path_config_root.go

@@ -37,9 +37,6 @@ func pathConfigRoot() *framework.Path {
 func pathConfigRootWrite(
 	req *logical.Request, data *framework.FieldData) (*logical.Response, error) {
 	region := data.Get("region").(string)
-	if region == "" {
-		region = "us-east-1"
-	}
 
 	entry, err := logical.StorageEntryJSON("config/root", rootConfig{
 		AccessKey: data.Get("access_key").(string),

helper/awsutil/generate_credentials.go

@@ -6,9 +6,7 @@ import (
 
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/credentials"
-	"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
-	"github.com/aws/aws-sdk-go/aws/ec2metadata"
-	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/aws/aws-sdk-go/aws/defaults"
 )
 
 type CredentialsConfig struct {
@@ -65,14 +63,14 @@ func (c *CredentialsConfig) GenerateCredentialChain() (*credentials.Credentials,
 		Profile:  c.Profile,
 	})
 
-	// Add the instance metadata role provider
-	providers = append(providers, &ec2rolecreds.EC2RoleProvider{
-		Client: ec2metadata.New(session.New(&aws.Config{
-			Region:     aws.String(c.Region),
-			HTTPClient: c.HTTPClient,
-		})),
-		ExpiryWindow: 15,
-	})
+	// Add the remote provider
+	def := defaults.Get()
+	if c.Region != "" {
+		def.Config.Region = aws.String(c.Region)
+	}
+	def.Config.HTTPClient = c.HTTPClient
+
+	providers = append(providers, defaults.RemoteCredProvider(*def.Config, def.Handlers))
 
 	// Create the credentials required to access the API.
 	creds := credentials.NewChainCredentials(providers)

physical/dynamodb.go

@@ -3,6 +3,7 @@ package physical
 import (
 	"fmt"
 	"math"
+	"net/http"
 	"os"
 	pkgPath "path"
 	"sort"
@@ -16,14 +17,14 @@ import (
 	"github.com/armon/go-metrics"
 	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/awserr"
-	"github.com/aws/aws-sdk-go/aws/credentials"
-	"github.com/aws/aws-sdk-go/aws/credentials/ec2rolecreds"
-	"github.com/aws/aws-sdk-go/aws/ec2metadata"
 	"github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/dynamodb"
 	"github.com/aws/aws-sdk-go/service/dynamodb/dynamodbattribute"
 	"github.com/hashicorp/errwrap"
+	cleanhttp "github.com/hashicorp/go-cleanhttp"
 	"github.com/hashicorp/go-uuid"
+	"github.com/hashicorp/vault/helper/awsutil"
+	"github.com/hashicorp/vault/helper/consts"
 )
 
 const (
@@ -166,29 +167,37 @@ func newDynamoDBBackend(conf map[string]string, logger log.Logger) (Backend, err
 	if endpoint == "" {
 		endpoint = conf["endpoint"]
 	}
-	region := os.Getenv("AWS_DEFAULT_REGION")
+	region := os.Getenv("AWS_REGION")
 	if region == "" {
-		region = conf["region"]
+		region = os.Getenv("AWS_DEFAULT_REGION")
 		if region == "" {
-			region = DefaultDynamoDBRegion
+			region = conf["region"]
+			if region == "" {
+				region = DefaultDynamoDBRegion
+			}
 		}
 	}
 
-	creds := credentials.NewChainCredentials([]credentials.Provider{
-		&credentials.StaticProvider{Value: credentials.Value{
-			AccessKeyID:     accessKey,
-			SecretAccessKey: secretKey,
-			SessionToken:    sessionToken,
-		}},
-		&credentials.EnvProvider{},
-		&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
-		&ec2rolecreds.EC2RoleProvider{Client: ec2metadata.New(session.New())},
-	})
+	credsConfig := &awsutil.CredentialsConfig{
+		AccessKey:    accessKey,
+		SecretKey:    secretKey,
+		SessionToken: sessionToken,
+	}
+	creds, err := credsConfig.GenerateCredentialChain()
+	if err != nil {
+		return nil, err
+	}
+
+	pooledTransport := cleanhttp.DefaultPooledTransport()
+	pooledTransport.MaxIdleConnsPerHost = consts.ExpirationRestoreWorkerCount
 
 	awsConf := aws.NewConfig().
 		WithCredentials(creds).
 		WithRegion(region).
-		WithEndpoint(endpoint)
+		WithEndpoint(endpoint).
+		WithHTTPClient(&http.Client{
+			Transport: pooledTransport,
+		})
 	client := dynamodb.New(session.New(awsConf))
 
 	if err := ensureTableExists(client, table, readCapacity, writeCapacity); err != nil {

physical/s3.go

@@ -62,11 +62,14 @@ func newS3Backend(conf map[string]string, logger log.Logger) (Backend, error) {
 	if endpoint == "" {
 		endpoint = conf["endpoint"]
 	}
-	region := os.Getenv("AWS_DEFAULT_REGION")
+	region := os.Getenv("AWS_REGION")
 	if region == "" {
-		region = conf["region"]
+		region = os.Getenv("AWS_DEFAULT_REGION")
 		if region == "" {
-			region = "us-east-1"
+			region = conf["region"]
+			if region == "" {
+				region = "us-east-1"
+			}
 		}
 	}
 

website/source/api/secret/aws/index.html.md

@@ -23,13 +23,17 @@ are multiple ways to pass root IAM credentials to the Vault server, specified
 below with the highest precedence first. If credentials already exist, this will
 overwrite them.
 
+The official AWS SDK is used for sourcing credentials from env vars, shared
+files, or IAM/ECS instances.
+
 - Static credentials provided to the API as a payload
 
 - Credentials in the `AWS_ACCESS_KEY`, `AWS_SECRET_KEY`, and `AWS_REGION`
   environment variables **on the server**
 
-- Querying the EC2 metadata service if the **Vault server** is on EC2 and has
-  querying capabilities
+- Shared credentials files
+
+- Assigned IAM role or ECS task role credentials
 
 At present, this endpoint does not confirm that the provided AWS credentials are
 valid AWS credentials with proper permissions.
@@ -44,7 +48,9 @@ valid AWS credentials with proper permissions.
 
 - `secret_key` `(string: <required>)` – Specifies the AWS secret access key.
 
-- `region` `(string: <required>)` – Specifies the AWS region.
+- `region` `(string: <optional>)` – Specifies the AWS region. If not set it
+  will use the `AWS_REGION` env var, `AWS_DEFAULT_REGION` env var, or
+  `us-east-1` in that order.
 
 ### Sample Payload
 

website/source/docs/auth/aws.html.md

@@ -546,10 +546,10 @@ $ vault auth -method=aws header_value=vault.example.com role=dev-role-iam
 
 This assumes you have AWS credentials configured in the standard locations AWS
 SDKs search for credentials (environment variables, ~/.aws/credentials, IAM
-instance profile in that order). If you do not have IAM credentials available at
-any of these locations, you can explicitly pass them in on the command line
-(though this is not recommended), omitting `aws_security_token` if not
-applicable .
+instance profile, or ECS task role, in that order). If you do not have IAM
+credentials available at any of these locations, you can explicitly pass them
+in on the command line (though this is not recommended), omitting
+`aws_security_token` if not applicable.
 
 ```
 $ vault auth -method=aws header_value=vault.example.com role=dev-role-iam \

website/source/docs/configuration/storage/s3.html.md

@@ -35,10 +35,11 @@ storage "s3" {
 
 - `endpoint` `(string: "")` – Specifies an alternative, AWS compatible, S3
   endpoint. This can also be provided via the environment variable
-  `AWS_DEFAULT_REGION`.
+  `AWS_S3_ENDPOINT`.
 
 - `region` `(string "us-east-1")` – Specifies the AWS region. This can also be
-  provided via the environment variable `AWS_DEFAULT_REGION`.
+  provided via the environment variable `AWS_REGION` or `AWS_DEFAULT_REGION`,
+  in that order of preference.
 
 The following settings are used for authenticating to AWS. If you are
 running your Vault server on an EC2 instance, you can also make use of the EC2

website/source/docs/secrets/aws/index.html.md

@@ -43,10 +43,16 @@ The following parameters are required:
   credentials.
 - `secret_key` - the AWS secret key that has permission to manage IAM
   credentials.
-- `region` the AWS region for API calls.
 
-Note: the client uses the official AWS SDK and will use environment variable or IAM
-role-provided credentials if available.
+The following parameter is optional:
+
+- `region` the AWS region for API calls. If not provided, the `AWS_REGION` and
+  `AWS_DEFAULT_REGION` env vars will be used, in that order. If there is still
+  no region, `us-east-1` will be used as a fallback.
+
+Note: the client uses the official AWS SDK and will use the specified
+credentials, environment credentials, shared file credentials, or IAM role/ECS
+task credentials in that order.
 
 The next step is to configure a role. A role is a logical name that maps
 to a policy used to generated those credentials.