Are you tired of dealing with the complexities of AWS Identity and Access Management (IAM) roles and tokens? Do you want to learn how to use AWS CDK to create a role with a preferred_role claim in tokens? Look no further! In this article, we’ll take you on a journey to explore the world of AWS CDK and show you how to create a role with a preferred_role claim in tokens.
What is AWS CDK?
AWS CDK (Cloud Development Kit) is an open-source framework that allows you to define cloud infrastructure in code. It provides a set of pre-defined resources, known as constructs, that you can use to create and manage AWS resources. With AWS CDK, you can write infrastructure as code (IaC) in familiar programming languages like TypeScript, JavaScript, Python, Java, and C#.
What is a Preferred_Role Claim in Tokens?
A preferred_role claim in tokens is a feature in AWS that allows you to specify a preferred IAM role for an IAM user or federated identity. This feature is useful when you want to allow users to assume a specific role when accessing AWS resources. By including the preferred_role claim in the token, you can ensure that the user assumes the correct role and has the necessary permissions.
Why Use a Preferred_Role Claim in Tokens?
There are several benefits to using a preferred_role claim in tokens:
- Simplified Role Management**: By specifying a preferred role, you can simplify the process of managing roles and permissions for your users.
- Improved Security**: A preferred_role claim ensures that users assume the correct role and have the necessary permissions, reducing the risk of unauthorized access.
- Enhanced User Experience**: Users don’t need to manually switch between roles, making it easier for them to access the resources they need.
Creating an AWS CDK Role with a Preferred_Role Claim in Tokens
Now that we’ve covered the basics, let’s dive into the main event! Creating an AWS CDK role with a preferred_role claim in tokens involves several steps:
Step 1: Create an IAM Role
First, you need to create an IAM role that will be used as the preferred role. You can do this using the AWS Management Console or the AWS CLI. For this example, we’ll use the AWS CLI:
aws iam create-role --role-name my-role --assume-role-policy-document file://role-policy.json
The `role-policy.json` file should contain the following policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Principal": {
"Service": "ec2.amazonaws.com"
},
"Action": "sts:AssumeRole"
}
]
}
Step 2: Create an AWS CDK Stack
Next, you need to create an AWS CDK stack that will define the resources for your role. Create a new file called `cdk-stack.ts` with the following code:
import * as cdk from 'aws-cdk-lib';
import * as iam from 'aws-cdk-lib/aws-iam';
export class MyStack extends cdk.Stack {
constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
const role = new iam.Role(this, 'MyRole', {
assumedBy: new iam.ServicePrincipal('ec2.amazonaws.com'),
});
new iam.RolePolicyAttachment(this, 'MyPolicy', {
role,
policy: iam.PolicyDocument.fromJson({
statements: [
new iam.PolicyStatement({
effect: iam.Effect.ALLOW,
actions: ['s3:GetObject', 's3:PutObject'],
resources: ['arn:aws:s3:::my-bucket/*'],
}),
],
}),
});
}
}
Step 3: Add the Preferred_Role Claim to the Token
To add the preferred_role claim to the token, you need to modify the IAM role policy to include the `sts:TagSession` permission. Update the `cdk-stack.ts` file with the following code:
import * as cdk from 'aws-cdk-lib';
import * as iam from 'aws-cdk-lib/aws-iam';
export class MyStack extends cdk.Stack {
constructor(scope: cdk.Construct, id: string, props?: cdk.StackProps) {
super(scope, id, props);
const role = new iam.Role(this, 'MyRole', {
assumedBy: new iam.ServicePrincipal('ec2.amazonaws.com'),
});
new iam.RolePolicyAttachment(this, 'MyPolicy', {
role,
policy: iam.PolicyDocument.fromJson({
statements: [
new iam.PolicyStatement({
effect: iam.Effect.ALLOW,
actions: ['s3:GetObject', 's3:PutObject', 'sts:TagSession'],
resources: ['arn:aws:s3:::my-bucket/*', 'arn:aws:iam::123456789012:role/my-role'],
}),
],
}),
});
new iam.RolePolicyAttachment(this, 'PreferredRolePolicy', {
role,
policy: iam.PolicyDocument.fromJson({
statements: [
new iam.PolicyStatement({
effect: iam.Effect.ALLOW,
actions: ['sts:GetFederationToken'],
resources: ['*'],
conditions: {
StringLike: {
'sts:PreferredRole': 'my-role',
},
},
}),
],
}),
});
}
}
Step 4: Deploy the AWS CDK Stack
Finally, deploy the AWS CDK stack using the following command:
cdk deploy
This will create the IAM role and attach the necessary policies.
Verifying the Preferred_Role Claim in Tokens
To verify that the preferred_role claim is included in the token, you can use the AWS CLI to get a federated token:
aws sts get-federation-token --duration-seconds 3600 --name my-user --policy file://policy.json
The `policy.json` file should contain the following policy:
{
"Version": "2012-10-17",
"Statement": [
{
"Effect": "Allow",
"Action": "sts:GetFederationToken",
"Resource": "*",
"Condition": {
"StringLike": {
"sts:PreferredRole": "my-role"
}
}
}
]
}
This will return a token that includes the preferred_role claim. You can verify this by decoding the token:
jwt.decode(token)
This should display the token claims, including the preferred_role claim:
{
"iss": "https://url.to.issuer",
"aud": "https://url.to.audience",
"iat": 1643723400,
"exp": 1643726800,
"preferred_role": "my-role",
"sub": "my-user"
}
Conclusion
In this article, we’ve covered the process of creating an AWS CDK role with a preferred_role claim in tokens. By following these steps, you can simplify role management, improve security, and enhance the user experience. Remember to verify the preferred_role claim in tokens to ensure that it’s working as expected.
Additional Resources
| Keyword | Description |
|---|---|
| AWS CDK | AWS Cloud Development Kit |
| Preferred_Role Claim | A feature in AWS that allows you to specify a preferred IAM role for an IAM user or federated identity |
| Token | A security token issued by AWS that includes claims and permissions |
| IAM Role | A role that defines a set of permissions and policies for an IAM user or federated identity |
| Federated Identity | A user or service that uses temporary security credentials to access AWS resources |
Note: The article is optimized for the keyword “
Frequently Asked Question
Confused about AWS CDK role with preferred_role claim in tokens? Don’t worry, we’ve got you covered!
What is the purpose of the preferred_role claim in AWS CDK role?
The preferred_role claim is used to specify the preferred IAM role that the AWS CDK should assume when interacting with AWS services. This allows you to control the permissions and access levels of your CDK applications.
How does the AWS CDK use the preferred_role claim in tokens?
When the AWS CDK authenticates with AWS using an OIDC token, it extracts the preferred_role claim from the token and uses it to assume the specified IAM role. This allows the CDK to access AWS resources with the required permissions.
Can I specify multiple preferred roles in the token?
No, you can only specify one preferred role in the token. If you need to access multiple roles, you’ll need to create separate tokens with different preferred_roles claims.
What happens if the preferred_role claim is not specified in the token?
If the preferred_role claim is not specified, the AWS CDK will default to using the AWS CLI’s default role or the role specified in the AWS CDK configuration file.
Can I override the preferred_role claim in the token with a different role?
Yes, you can override the preferred_role claim in the token by specifying a different role using the AWS CDK’s `–role` command-line option or by configuring a different role in the AWS CDK configuration file.
