This module provides a factory function, fromEnv, that will attempt to source AWS credentials from a Node.JS environment. It will attempt to find credentials from the following sources (listed in order of precedence):

• Environment variables exposed via process.env
• SSO credentials from token cache
• Web identity token credentials
• Shared credentials and config ini files
• The EC2/ECS Instance Metadata Service

The default credential provider will invoke one provider at a time and only continue to the next if no credentials have been located. For example, if the process finds values defined via the AWS_ACCESS_KEY_ID and AWS_SECRET_ACCESS_KEY environment variables, the files at ~/.aws/credentials and ~/.aws/config will not be read, nor will any messages be sent to the Instance Metadata Service.

If invalid configuration is encountered (such as a profile in ~/.aws/credentials specifying as its source_profile the name of a profile that does not exist), then the chained provider will be rejected with an error and will not invoke the next provider in the list.

IMPORTANT: if you intend to acquire credentials using EKS IAM Roles for Service Accounts then you must explicitly specify a value for roleAssumerWithWebIdentity. There is a default function available in @aws-sdk/client-sts package. An example of using this:

const { getDefaultRoleAssumerWithWebIdentity } = require("@aws-sdk/client-sts");
const { defaultProvider } = require("@aws-sdk/credential-provider-node");
const { S3Client, GetObjectCommand } = require("@aws-sdk/client-s3");

const provider = defaultProvider({
  roleAssumerWithWebIdentity: getDefaultRoleAssumerWithWebIdentity({
    // You must explicitly pass a region if you are not using us-east-1
    region: "eu-west-1"
  }),
});

const client = new S3Client({ credentialDefaultProvider: provider });

IMPORTANT: We provide a wrapper of this provider in @aws-sdk/credential-providers package to save you from importing getDefaultRoleAssumerWithWebIdentity() or getDefaultRoleAssume() from STS package. Similarly, you can do:

const { fromNodeProviderChain } = require("@aws-sdk/credential-providers");

const credentials = fromNodeProviderChain();

const client = new S3Client({ credentials });

You may customize how credentials are resolved by providing an options hash to the defaultProvider factory function. The following options are supported:

• profile - The configuration profile to use. If not specified, the provider will use the value in the AWS_PROFILE environment variable or a default of default.
• filepath - The path to the shared credentials file. If not specified, the provider will use the value in the AWS_SHARED_CREDENTIALS_FILE environment variable or a default of ~/.aws/credentials.
• configFilepath - The path to the shared config file. If not specified, the provider will use the value in the AWS_CONFIG_FILE environment variable or a default of ~/.aws/config.
• mfaCodeProvider - A function that returns a a promise fulfilled with an MFA token code for the provided MFA Serial code. If a profile requires an MFA code and mfaCodeProvider is not a valid function, the credential provider promise will be rejected.
• roleAssumer - A function that assumes a role and returns a promise fulfilled with credentials for the assumed role. If not specified, no role will be assumed, and an error will be thrown.
• roleArn - ARN to assume. If not specified, the provider will use the value in the AWS_ROLE_ARN environment variable.
• webIdentityTokenFile - File location of where the OIDC token is stored. If not specified, the provider will use the value in the AWS_WEB_IDENTITY_TOKEN_FILE environment variable.
• roleAssumerWithWebIdentity - A function that assumes a role with web identity and returns a promise fulfilled with credentials for the assumed role.
• timeout - The connection timeout (in milliseconds) to apply to any remote requests. If not specified, a default value of 1000 (one second) is used.
• maxRetries - The maximum number of times any HTTP connections should be retried. If not specified, a default value of 0 will be used.

• AWS Credential Provider for Node.JS - Environment Variables
• AWS Credential Provider for Node.JS - SSO
• AWS Credential Provider for Node.JS - Web Identity
• AWS Credential Provider for Node.JS - Shared Configuration Files
• AWS Credential Provider for Node.JS - Instance and Container Metadata
• AWS Shared Configuration File Loader