Use KCL 1.* in Lambda: Credentials - amazon-web-services

Question

Using the examples provided in https://github.com/aws/aws-sdk-java/tree/master/src/samples/AmazonKinesis I understand how to use the KCL to read KinesisEvents from my local machine.
I am trying to implement the same logic in Lambda Functions.
To set up the KinesisClientLibConfiguration, you need to provide an AWSCredentialsProvider.
Where do I get these AWSCredentials to create the kinesisClientLibConfiguration in a Lambda?
KinesisClientLibConfiguration kinesisClientLibConfiguration = new KinesisClientLibConfiguration(SAMPLE_APPLICATION_NAME, SAMPLE_APPLICATION_STREAM_NAME, credentialsProvider, workerId);
The full code of the handler looks like this:
public class ProcessKinesisRecords implements RequestHandler<KinesisEvent, Void> {
public static final String SAMPLE_APPLICATION_STREAM_NAME = "kinesis-s";
public static final String SAMPLE_APPLICATION_STREAM_REGION = "eu-west-1";
private static final String SAMPLE_APPLICATION_NAME = "SampleKinesisLambdaApplication";
private static final InitialPositionInStream SAMPLE_APPLICATION_INITIAL_POSITION_IN_STREAM =
InitialPositionInStream.LATEST;
private static ProfileCredentialsProvider credentialsProvider;
public Void handleRequest(KinesisEvent event, Context context) {
init();
int exitCode = 0;
try {
String workerId = InetAddress.getLocalHost().getCanonicalHostName() + ":" + UUID.randomUUID();
KinesisClientLibConfiguration kinesisClientLibConfiguration =
new KinesisClientLibConfiguration(SAMPLE_APPLICATION_NAME,
SAMPLE_APPLICATION_STREAM_NAME,
credentialsProvider,
workerId);
kinesisClientLibConfiguration.withInitialPositionInStream(SAMPLE_APPLICATION_INITIAL_POSITION_IN_STREAM);
kinesisClientLibConfiguration.withRegionName(SAMPLE_APPLICATION_STREAM_REGION);
IRecordProcessorFactory recordProcessorFactory = new AmazonKinesisApplicationRecordProcessorFactory();
Worker worker = new Worker(recordProcessorFactory, kinesisClientLibConfiguration);
System.out.printf("Running %s to process stream %s as worker %s...\n",
SAMPLE_APPLICATION_NAME,
SAMPLE_APPLICATION_STREAM_NAME,
workerId);
worker.run();
} catch (Throwable e) {
System.err.println("Caught throwable while processing data.");
e.printStackTrace();
}
System.exit(exitCode);
return null;
}
private static void init() {
// Ensure the JVM will refresh the cached IP values of AWS resources (e.g. service endpoints).
java.security.Security.setProperty("networkaddress.cache.ttl", "60");
credentialsProvider = new ProfileCredentialsProvider();
try {
credentialsProvider.getCredentials();
} catch (Exception e) {
throw new AmazonClientException("Cannot load the credentials", e);
}
}
}

Answer 1

Lambda does provide environment variables for the credentials:
https://docs.aws.amazon.com/lambda/latest/dg/current-supported-versions.html#lambda-environment-variables
Access them via the EnvironmentVariableCredentialsProvider:
https://github.com/aws/aws-sdk-java/blob/master/aws-java-sdk-core/src/main/java/com/amazonaws/auth/EnvironmentVariableCredentialsProvider.java