fix: load AWS config and assume role

pkg/repository/config/aws.go

@@ -23,9 +23,12 @@ import (
 
 	goerr "errors"
 
+	"github.com/aws/aws-sdk-go/aws"
 	"github.com/aws/aws-sdk-go/aws/credentials"
+	"github.com/aws/aws-sdk-go/aws/credentials/stscreds"
 	"github.com/aws/aws-sdk-go/aws/endpoints"
 	"github.com/aws/aws-sdk-go/aws/session"
+	aws_session "github.com/aws/aws-sdk-go/aws/session"
 	"github.com/aws/aws-sdk-go/service/s3/s3manager"
 	"github.com/pkg/errors"
 )
@@ -57,26 +60,22 @@ func GetS3ResticEnvVars(config map[string]string) (map[string]string, error) {
 // GetS3Credentials gets the S3 credential values according to the information
 // of the provided config or the system's environment variables
 func GetS3Credentials(config map[string]string) (*credentials.Value, error) {
-	if len(os.Getenv("AWS_ROLE_ARN")) > 0 {
+	if os.Getenv("AWS_ROLE_ARN") != "" && os.Getenv("AWS_SHARED_CREDENTIALS_FILE") == "" {
 		return nil, nil
 	}
 
-	credentialsFile := config[CredentialsFileKey]
-	if credentialsFile == "" {
-		credentialsFile = os.Getenv("AWS_SHARED_CREDENTIALS_FILE")
-	}
-
-	if credentialsFile == "" {
-		return nil, errors.New("missing credential file")
-	}
-
-	creds := credentials.NewSharedCredentials(credentialsFile, "")
-	credValue, err := creds.Get()
+	awsConfig := aws.NewConfig().WithMaxRetries(2)
+	sess, err := aws_session.NewSession(awsConfig)
 	if err != nil {
 		return nil, err
 	}
+	if len(os.Getenv("AWS_ROLE_ARN")) > 0 {
+		sess.Config.WithCredentials(stscreds.NewCredentials(sess, os.Getenv("AWS_ROLE_ARN")))
+	}
+
+	creds, err := sess.Config.Credentials.Get()
 
-	return &credValue, nil
+	return &creds, err
 }
 
 // GetAWSBucketRegion returns the AWS region that a bucket is in, or an error