how to get AWS credential from ECR with golang

aws-ecr-credential.go

/*
 * Copyright (c) 2019. Inception Asia
 * Maintain by DigithunWorldwide ❤
 * Maintainer
 * - rungsikorn.r@digithunworldwide.com
 * - nipon.chi@digithunworldwide.com
 */

package util

import (
	"fmt"
	"github.com/aws/aws-sdk-go/aws"
	"github.com/aws/aws-sdk-go/aws/credentials"
	"github.com/pkg/errors"
	"github.com/tidwall/gjson"
	"io/ioutil"
	"net/http"
	"os"
)

type ContainerCredentialProvider struct{}

func (m *ContainerCredentialProvider) Retrieve() (credentials.Value, error) {
	awsContainerURI := os.Getenv("AWS_CONTAINER_CREDENTIALS_RELATIVE_URI")

	if len(awsContainerURI) < 1 {
		fmt.Println("[AWS] ECS URI not found, SKIP THIS IF YOU RUNNING OUTSIDE ECS")
		return credentials.Value{}, errors.New("No ECS URI")
	}

	ecsCredentialURL := fmt.Sprintf("http://169.254.170.2%s", awsContainerURI)

	r, err := http.Get(ecsCredentialURL)
	if err != nil {
		panic(err)
	}
	defer r.Body.Close()

	b, _ := ioutil.ReadAll(r.Body)
	fmt.Println("Result")
	awsID := gjson.Get(string(b), "AccessKeyId").String()
	awsSecret := gjson.Get(string(b), "SecretAccessKey").String()
	awsToken := gjson.Get(string(b), "Token").String()
	return credentials.Value{
		SecretAccessKey: awsSecret,
		SessionToken:    awsToken,
		AccessKeyID:     awsID,
		ProviderName:    "ECS Container Credential",
	}, nil
}

func (m *ContainerCredentialProvider) IsExpired() bool {
	return false
}

type AWSConfigOptions struct {
	AWS              *aws.Config
	AWSAccountID     string
	AWSAccountSecret string
}

// Prepare will block thread until it complete gathering resource
func NewAWSConfig(opts AWSConfigOptions) *aws.Config {

	fmt.Println("[AWS] init aws config...")
	fmt.Printf("Config\nID:%s\nSecret:%s\n", opts.AWSAccountID, opts.AWSAccountSecret)

	awsConfig := aws.Config{
		Region: aws.String("ap-southeast-1"),
		Credentials: credentials.NewChainCredentials([]credentials.Provider{
			&ContainerCredentialProvider{},
			&credentials.StaticProvider{
				Value: credentials.Value{
					ProviderName:    "User define",
					AccessKeyID:     opts.AWSAccountID,
					SessionToken:    "",
					SecretAccessKey: opts.AWSAccountSecret,
				},
			},
		}),
	}

	return &awsConfig
}