Amazon EC2 Instance Metadata Service

You can use the Amazon SDK for Go to access the Amazon EC2 Instance Metadata Service. The feature/ec2/imds Go package provides a Client type that can be used to access the Amazon EC2 Instance Metadata Service. The Client and associated operations can be used similar to the other Amazon service clients provided by the SDK. To learn more information on how to configure the SDK, and use service clients see Configure the SDK and Use the Amazon SDK for Go v2 with Amazon services.

The client can help you easily retrieve information about instances on which your applications run, such as its Amazon Region or local IP address. Typically, you must create and submit HTTP requests to retrieve instance metadata. Instead, create an imds.Client to access the Amazon EC2 Instance Metadata Service using a programmatic client like other Amazon Services.

For example to construct a client:

import "context"
import "github.com/aws/aws-sdk-go-v2/config"
import "github.com/aws/aws-sdk-go-v2/feature/ec2/imds"

// ...

cfg, err := config.LoadDefaultConfig(context.TODO())
if err != nil {
    log.Printf("error: %v", err)
    return
}

client := imds.NewFromConfig(cfg)

Then use the service client to retrieve information from a metadata category such as local-ipv4 (the private IP address of the instance).

localIp, err := client.GetMetadata(context.TODO(), &imds.GetMetadataInput{
    Path: "local-ipv4",
})
if err != nil {
    log.Printf("Unable to retrieve the private IP address from the EC2 instance: %s\n", err)
    return
}
content, _ := io.ReadAll(localIp.Content)
fmt.Printf("local-ip: %v\n", string(content))

For a list of all metadata categories, see Instance metadata categories in the Amazon EC2 User Guide.