我在golang中有以下代码，用于读取文件并提取文件的一些列，fileName是从我的lambda接收的，但在我的第一步，即从s3获取文件时，我遇到了一个问题。
我的代码是：

package main

import (
    "fmt"
    "packageXXX/cmd/utils"

    "github.com/aws/aws-lambda-go/lambda"
    "github.com/aws/aws-sdk-go/aws"
    "github.com/aws/aws-sdk-go/aws/session"
    "github.com/aws/aws-sdk-go/service/s3"
    "github.com/aws/aws-sdk-go/service/s3/s3manager"
    "go.uber.org/zap"
)

var (
    log *zap.Logger
)

func init() {
    log = utils.InitLogger()
}

func DownloadFile(downloader *s3manager.Downloader, bucketName string, key string) error {

    buff := &aws.WriteAtBuffer{}

    numBytes, err := downloader.Download(
        buff,
        &s3.GetObjectInput{
            Bucket: aws.String(bucketName),
            Key:    aws.String(key),
        },
    )

    data := buff.Bytes() // now data is my []byte array

    log.Info("nnnnnnnnnnnnnnn", zap.Any("nnn", numBytes))
    log.Info("xxxxxxxxxxxxxxx", zap.Any("bytes", data))
    return err
}

func handler(fileName string) (string, error) {
    log.Info(fmt.Sprintf("received: %s", fileName))
    sess, err := session.NewSessionWithOptions(session.Options{
        Profile: "default",
        Config: aws.Config{
            Region: aws.String("us-west-2"),
        },
    })

    if err != nil {
        log.Info("errorrrrrrrrr", zap.Any("session", err))
        return "errorr,", nil
    } else {
        log.Info("sessionnnnnnnnnnnnnn", zap.Any("sess", sess))
    }

    bucketName := "s3-test-lambda-go-xxx"
    downloader := s3manager.NewDownloader(sess)
    log.Info("downloader", zap.Any("downloader", err))
    key := fileName
    err = DownloadFile(downloader, bucketName, key)

    if err != nil {
        fmt.Printf("Couldn't download file: %v", err)
        return "errror", nil
    }

    fmt.Println("Successfully downloaded file")

    return fmt.Sprintf("el file recibido es: %s", fileName), nil
}

func main() {
    lambda.Start(handler)
}

正在打印的日志为：

For verbose messaging see aws.Config.CredentialsChainVerboseErrorsSTART RequestId: dba8ebd5-9102-4a2f-8e45-cdef355f1bbd Version: $LATEST
{"level":"info","ts":"2022-11-02T17:31:32Z","msg":"received: gggggg2.txt"}
{"level":"info","ts":"2022-11-02T17:31:32Z","msg":"sessionnnnnnnnnnnnnn","sessError":"json: unsupported type: endpoints.endpointDefaults"}
{"level":"info","ts":"2022-11-02T17:31:32Z","msg":"downloader","downloader":null}
{"level":"info","ts":"2022-11-02T17:31:38Z","msg":"nnnnnnnnnnnnnnn","nnn":0}
{"level":"info","ts":"2022-11-02T17:31:38Z","msg":"xxxxxxxxxxxxxxx","bytes":""}
Couldn't download file: NoCredentialProviders: no valid providers in chain. Deprecated.
END RequestId: dba8ebd5-9102-4a2f-8e45-cdef355f1bbd

问题是会话
那么是否可以创建与角色的会话，因为像是生产我不想使用访问和密钥？谢谢