Lambda PutObjectCommand 失败并显示“解析的凭证对象无效”

Question

我有一个 lambda 尝试将一个对象放入 S3 存储桶中。

配置s3客户端的代码如下：

const configuration: S3ClientConfig = {
  region: 'us-west-2',
};

if (process.env.DEVELOPMENT_MODE) {
  configuration.credentials = {
    accessKeyId: process.env.AWS_ACCESS_KEY!,
    secretAccessKey: process.env.AWS_SECRET_KEY!,
  }
}

export const s3 = new S3Client(configuration);

上传文件的代码如下：

s3.send(new PutObjectCommand({
  Bucket: bucketName,
  Key: fileName,
  ContentType: contentType,
  Body: body,
}))

这在本地有效。lambda 的角色包括一个策略，该策略又包含以下语句：

{
    "Action": [
        "s3:DeleteObject",
        "s3:PutObject"
    ],
    "Resource": [
        "arn:aws:s3:::BUCKET_NAME/*"
    ],
    "Effect": "Allow"
}

但是，当我调用此 lambda 时，它会失败并显示以下堆栈跟踪

Error: Resolved credential object is not valid
    at SignatureV4.validateResolvedCredentials (webpack://backend/../node_modules/@aws-sdk/signature-v4-multi-region/node_modules/@aws-sdk/signature-v4/dist-es/SignatureV4.js?:307:19)
    at SignatureV4.eval (webpack://backend/../node_modules/@aws-sdk/signature-v4-multi-region/node_modules/@aws-sdk/signature-v4/dist-es/SignatureV4.js?:50:30)
    at step (webpack://backend/../node_modules/tslib/tslib.es6.js?:130:23)
    at Object.eval [as next] (webpack://backend/../node_modules/tslib/tslib.es6.js?:111:53)
    at fulfilled (webpack://backend/../node_modules/tslib/tslib.es6.js?:101:58)

我正在使用（当前）最新的 javascript aws sdk，版本 3.165.0。我在这里缺少什么？

Answer 1

问题是我试图从环境变量加载配置凭证，而不是依赖 IAM 角色。结果process.env.DEVELOPMENT_MODE是解析为 string'true'而不是 boolean true。

if (process.env.DEVELOPMENT_MODE === 'true') {
  configuration.credentials = {
    accessKeyId: process.env.AWS_ACCESS_KEY!,
    secretAccessKey: process.env.AWS_SECRET_KEY!,
  }
}