A developer is locally testing a Node.js microservice that integrates with Amazon S3. The developer wants the service to run using the AWS credentials of a development account, which are configured under a custom profile named `[dev]` in the local `~/.aws/credentials` file.
The developer's workstation also has the environment variables `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` set to credentials representing a secondary testing AWS account.
The client is initialized as follows:
javascript
import { S3Client } from "@aws-sdk/client-s3";
const s3Client = new S3Client({ profile: "dev" });
During test execution, the developer notices that S3 requests are being sent to the secondary testing account instead of the development account.
Why is the S3 client using the incorrect credentials, and how should this be resolved?
- The `profile` parameter is not a valid configuration option for the `S3Client` constructor. The SDK falls back to the default credential provider chain, which prioritizes the `AWS_ACCESS_KEY_ID` and `AWS_SECRET_ACCESS_KEY` environment variables. To resolve this, the developer must import the `fromIni` provider from `@aws-sdk/credential-providers` and pass it to the constructor: `new S3Client({ credentials: fromIni({ profile: 'dev' }) })`.Answer
- BThe default credential provider chain is failing to load the `[dev]` profile because active environment variables override shared credential files. To bypass the default chain, the developer must hardcode the development account's access key and secret key directly into the client initialization options: `new S3Client({ credentials: { accessKeyId: 'AKIAIOSFODNN7EXAMPLE', secretAccessKey: 'wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY' } })`.
- CThe `profile` parameter is ignored because credentials containing sensitive keys must be loaded from a secure storage service. To resolve this, the developer must upload the credentials to the AWS Systems Manager Parameter Store as a SecureString parameter and configure the S3 client to retrieve them dynamically by providing the parameter ARN in the constructor options.
- DThe SDK is unable to assume the IAM role associated with the `[dev]` profile because the IAM User's policy is missing a trust relationship with the local machine. To resolve this, the developer must update the IAM role's trust policy to allow the `sts:AssumeRole` action for the local machine's IP address and specify the role ARN in the client configuration.