What is ARN in AWS? A Guide to ARN AWS and Its Uses

Introduction

Nowadays, having a cloud system for your business is trending immensely. Most businesses have adopted this trend and have started using the cloud pioneer Amazon Web Services (AWS). AWS is a leader in cloud computing and Infrastructure-as-a-Service (IaaS.)  

Amazon Resource Names (ARNs) are used to identify individual AWS resources. These ARNs in AWS are majorly used for API Calls, IAM Policies, and Amazon Relational Database Services (RDS). They play an important role in IAM policies and IAM Permissions. 

ARNs access AWS resources without creating and saving any credentials depending on long-term access keys. This article will walk you through ARNs and explain how you can configure your ARN in AWS for various services.

What is an ARN in AWS?

ARNs are exclusive identifiers assigned to individual AWS resources. They are used to specify a resource unmistakable through all of AWS, as in API Calls, Amazon RDS tags, and IAM Policies. For certain Amazon RDS operations, you can exclusively identify an Amazon RDS resource by its ARN. 

What is ARN in AWS used for?

Administrators use ARNs in AWS to track and use AWS policies and items across all AWS Products and API Calls. ARN-based credentials offer better security, as you do not need any long-term credentials to access AWS resources. 

ARNs in AWS are crucial for IAM policies. If you follow the standard security best practices for IAM policies and roles, you will use ARNs. They grant restricted granular access to resources in IAM Policies. ARNs in AWS are also used in API Calls and automation scripts to signify to other resources. Furthermore, ARNs are used in the IAM permissions system to whitelist access to certain AWS resources rather than providing service-wide access.

How do I find my ARN in AWS?

For some services, you can find your ARN easily from the resource’s info page. It will start from arn:aws:. If it is an S3 service, you can simply copy it from the sidebar of the info page. 

For other services, such as EC2 in particular, the ARN is not displayed. Thus, you have to manually construct the ARN in AWS from the command line, according to the format given below: 

arn:${Partition}:ec2:${Region}:${Account}:instance/${InstanceId} 

How do I find my resource ARN in AWS?

You can get the ARN of an RDS resource using the AWS management console, RDS API, or AWS command-line interface.  

• If you are using the AWS management console, you have to navigate to the resource you need the ARN for and click on the details of that resource. 
• If you use the RDS API, you can check the RDI resource operations from the list and use the ARN properties. 
• If you want to use the AWS Command line, you have to use the describe command for the resource. Then the table will show you the AWS CLI command, and you can use the ARN property to get the ARN. 

What is S3 ARN in AWS?

Amazon Simple Storage Service (S3) is an AWS service that offers storage for the internet. It is a highly scalable and secure storage system in the cloud. S3 enables you to store and retrieve data from anywhere and anytime. This system runs through AWS Management Console, which is also an easy-to-use interface. 

Amazon S3 uses buckets to store the data as objects. You can have more than one bucket to store objects. You can control the access, view logs and objects, and choose the geographical region for each bucket. Amazon uses S3 for its websites across the globe. Netflix, Tumbler, Pinterest, and Dropbox are some widely known companies that use S3. 

S3 ARN in AWS includes partition, service, and relative ID but excludes the namespace and AWS region.

• Partition: AWS is used for public partition. But if your resource is in China, then use aws-cn as the partition. 
• Service: S3 
• Relative ID: bucket-name or bucket-name/object-key. You can also use wildcards. 

According to this, the format of the S3 ARN is: arn:aws:s3:::bucket_name/key_name

What is Amazon EC2 ARN?

Amazon Elastic Compute Cloud (EC2) offers scalable computing capacity in AWS Cloud. It allows you to scale up or scale down to handle modification and reduces your need to forecast traffic. 

Amazon EC2 offers a virtual computing environment known as instances and a firewall that allows you to specify your ports, protocols, and source IP ranges. 

The general format of an EC2 ARN in AWS is: 

arn:aws-cn:[service]:[region]:[account]:resourceType/resourcePath 

According to this, the ARN for Amazon e2 will be: 

"arn:aws-cn:ec2:us-east-1:123456789012:instance/i-1234567890abcdef0" 

AWS offers benefits such as security, reliability, affordability, and scalability for your business. You can easily master Architecting on AWS. If you want to incorporate AWS into your business, you can take up AWS certification. They will teach you AWS in-depth and help you learn the various benefits of learning AWS Needs Analysis for your business. 

What is ARN Format?

ARNs in AWS can be an S3 bucket, EC2 instance, EBS volumes, load balancers, route tables, etc. It is easy to build an ARN URL if the console has not listed an ARN for a particular resource. The general format of ARN is below: 

arn:partition:service:region:account-id:resource-id 

arn:partition:service:region:account-id:resource-type/resource-id 

arn:partition:service:region:account-id:resource-type:resource-id 

• Partition: AWS splits into three regions–Public, GovCloud, and China. You are most likely to use a Public partition, so this value will always be “aws”. 
• Service: The service belongs to the AWS product such as S3, E2, etc. 
• Region: Depends upon the locality of the resource. For e.g., us-east-1 or us-west-2, etc. This can be left blank for certain resources. 
• Account ID: ID of your AWS account that owns the resource. 
• Resource ID: This varies from service to service. For S3, it can simply be the object’s ID, but this splits by resource type and ID number for other services. 
• Resource Type: Syntax for this varies greatly for each service. It often includes an indicator such as a slash or colon.