metadata

Linode Metadata Service Client for Go

This package allows Go projects to easily interact with the Linode Metadata Service.

Getting Started

Prerequisites

• Go >= 1.20
• A running Linode Instance

Installation

go get github.com/linode/go-metadata

Basic Example

The follow sample shows a simple Go project that initializes a new metadata client and retrieves various information about the current Linode.

package main

import (
	"context"
	"fmt"
	"log"

	metadata "github.com/linode/go-metadata"
)

func main() {
	// Create a new client
	client, err := metadata.NewClient(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	// Retrieve metadata about the current instance from the metadata API
	instanceInfo, err := client.GetInstance(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("Instance Label:", instanceInfo.Label)
}

Without Token Management

By default, metadata API tokens are automatically generated and refreshed without any user intervention. If you would like to manage API tokens yourself, this functionality can be disabled:

package main

import (
	"context"
	"fmt"
	"log"
	"os"

	metadata "github.com/linode/go-metadata"
)

func main() {
	// Get a token from the environment
	token := os.Getenv("LINODE_METADATA_TOKEN")

	// Create a new client
	client, err := metadata.NewClient(
		context.Background(), 
		metadata.ClientWithoutManagedToken(), 
		metadata.ClientWithToken(token),
	)
	if err != nil {
		log.Fatal(err)
	}

	// Retrieve metadata about the current instance from the metadata API
	instanceInfo, err := client.GetInstance(context.Background())
	if err != nil {
		log.Fatal(err)
	}

	fmt.Println("Instance Label:", instanceInfo.Label)
}

For more examples, visit the examples directory.

Documentation

See godoc for a complete documentation reference.

Testing

Before running tests on this project, please ensure you have a Linode Personal Access Token exported under the LINODE_TOKEN environment variable.

End-to-End Testing Using Ansible

This project contains an Ansible playbook to automatically deploy the necessary infrastructure and run end-to-end tests on it.

To install the dependencies for this playbook, ensure you have Python 3 installed and run the following:

make test-deps

After all dependencies have been installed, you can run the end-to-end test suite by running the following:

make e2e

If your local SSH public key is stored in a location other than ~/.ssh/id_rsa.pub, you may need to override the TEST_PUBKEY argument:

make TEST_PUBKEY=/path/to/my/pubkey e2e

NOTE: To speed up subsequent test runs, the infrastructure provisioned for testing will persist after the test run is complete. This infrastructure is safe to manually remove.

Manual End-to-End Testing

End-to-end tests can also be manually run using the make e2e-local target. This test suite is expected to run from within a Linode instance and will likely fail in other environments.

Contribution Guidelines

Want to improve metadata-go? Please start here.

License

This software is Copyright Akamai Technologies, Inc. and is released under the Apache 2.0 license.