Merge pull request #3235 from mitchellh/b-amazon-credentials-crash

Create a session for EC2RoleProvider; prevents crash; fixes #3123

builder/amazon/common/access_config.go

@@ -10,6 +10,8 @@ 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/mitchellh/packer/template/interpolate"
 )
 
@@ -42,6 +44,7 @@ func (c *AccessConfig) Config() (*aws.Config, error) {
 			return nil, err
 		}
 	} else {
+		sess := session.New(config)
 		creds = credentials.NewChainCredentials([]credentials.Provider{
 			&credentials.StaticProvider{Value: credentials.Value{
 				AccessKeyID:     c.AccessKey,
@@ -50,7 +53,9 @@ func (c *AccessConfig) Config() (*aws.Config, error) {
 			}},
 			&credentials.EnvProvider{},
 			&credentials.SharedCredentialsProvider{Filename: "", Profile: ""},
-			&ec2rolecreds.EC2RoleProvider{},
+			&ec2rolecreds.EC2RoleProvider{
+				Client: ec2metadata.New(sess),
+			},
 		})
 	}
 	return config.WithCredentials(creds), nil