How can I get EC2 instance metadata using Spring Cloud v3?

Question

I am working on a Java / Spring Boot / Spring application which was using Version 1 of the AWS Java SDK and version 2.4.4 of io.awspring.cloud.

This application is using the class io.awspring.cloud.core.env.ec2.AmazonEc2InstanceDataPropertySource like this, to get the AMI ID for the EC2 instance:

var amazonEc2InstanceDataPropertySource = new AmazonEc2InstanceDataPropertySource("xxx");

String amiId = getInstanceDataProperty(amazonEc2InstanceDataPropertySource,"ami-id", "N/A");

..and so on for other properties.

I have now upgraded this application to version 2 of the AWS Java SDK and version 3.0.2 of io.awspring.cloud. In the new version of io.awspring.cloud there is no class called AmazonEc2InstanceDataPropertySource.

How can I rewrite the existing code to work in the new version of this library to get EC2 instance metadata?

Answer 1

The AmazonEc2InstanceDataPropertySource class fetches EC2 instance metadata properties via the IMDS (Instance Metadata Service), for the current EC2 instance.

It seems to have been replaced with @EnableContextInstanceData (not needed in Spring Boot with the right configuration) & field injection using Value annotations.

In your case, as you're looking to get the AMI ID and other properties, inject these properties directly using the @Value annotation.

@Configuration
@EnableContextInstanceData
public static class MyConfig {}

@Value("${ami-id}")
private String amiId;

@Value("${hostname}")
private String hostname;

@Value("${instance-type}")
private String instanceType;

@Value("${services/domain}")
private String serviceDomain;