How Amazon Managed Streaming for Apache Kafka Works with IAM - Amazon Managed Streaming for Apache Kafka

How Amazon Managed Streaming for Apache Kafka Works with IAM

Before you use IAM to manage access to Amazon MSK, you should understand what IAM features are available to use with Amazon MSK. To get a high-level view of how Amazon MSK and other AWS services work with IAM, see AWS Services That Work with IAM in the IAM User Guide.

Amazon MSK Identity-Based Policies

With IAM identity-based policies, you can specify allowed or denied actions and resources as well as the conditions under which actions are allowed or denied. Amazon MSK supports specific actions, resources, and condition keys. To learn about all of the elements that you use in a JSON policy, see IAM JSON Policy Elements Reference in the IAM User Guide.

Actions

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Action element of a JSON policy describes the actions that you can use to allow or deny access in a policy. Policy actions usually have the same name as the associated AWS API operation. There are some exceptions, such as permission-only actions that don't have a matching API operation. There are also some operations that require multiple actions in a policy. These additional actions are called dependent actions.

Include actions in a policy to grant permissions to perform the associated operation.

Policy actions in Amazon MSK use the following prefix before the action: kafka:. For example, to grant someone permission to describe an MSK cluster with the Amazon MSK DescribeCluster API operation, you include the kafka:DescribeCluster action in their policy. Policy statements must include either an Action or NotAction element. Amazon MSK defines its own set of actions that describe tasks that you can perform with this service.

To specify multiple actions in a single statement, separate them with commas as follows:

"Action": ["kafka:action1", "kafka:action2"]

You can specify multiple actions using wildcards (*). For example, to specify all actions that begin with the word Describe, include the following action:

"Action": "kafka:Describe*"

To see a list of Amazon MSK actions, see Actions Defined by Amazon Managed Streaming for Apache Kafka in the IAM User Guide.

Resources

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Resource JSON policy element specifies the object or objects to which the action applies. Statements must include either a Resource or a NotResource element. As a best practice, specify a resource using its Amazon Resource Name (ARN). You can do this for actions that support a specific resource type, known as resource-level permissions.

For actions that don't support resource-level permissions, such as listing operations, use a wildcard (*) to indicate that the statement applies to all resources.

"Resource": "*"

The Amazon MSK instance resource has the following ARN:

arn:${Partition}:kafka:${Region}:${Account}:cluster/${ClusterName}/${UUID}

For more information about the format of ARNs, see Amazon Resource Names (ARNs) and AWS Service Namespaces.

For example, to specify the CustomerMessages instance in your statement, use the following ARN:

"Resource": "arn:aws:kafka:us-east-1:123456789012:cluster/CustomerMessages/abcd1234-abcd-dcba-4321-a1b2abcd9f9f-2"

To specify all instances that belong to a specific account, use the wildcard (*):

"Resource": "arn:aws:kafka:us-east-1:123456789012:cluster/*"

Some Amazon MSK actions, such as those for creating resources, cannot be performed on a specific resource. In those cases, you must use the wildcard (*).

"Resource": "*"

To specify multiple resources in a single statement, separate the ARNs with commas.

"Resource": ["resource1", "resource2"]

To see a list of Amazon MSK resource types and their ARNs, see Resources Defined by Amazon Managed Streaming for Apache Kafka in the IAM User Guide. To learn with which actions you can specify the ARN of each resource, see Actions Defined by Amazon Managed Streaming for Apache Kafka.

Condition Keys

Administrators can use AWS JSON policies to specify who has access to what. That is, which principal can perform actions on what resources, and under what conditions.

The Condition element (or Condition block) lets you specify conditions in which a statement is in effect. The Condition element is optional. You can create conditional expressions that use condition operators, such as equals or less than, to match the condition in the policy with values in the request.

If you specify multiple Condition elements in a statement, or multiple keys in a single Condition element, AWS evaluates them using a logical AND operation. If you specify multiple values for a single condition key, AWS evaluates the condition using a logical OR operation. All of the conditions must be met before the statement's permissions are granted.

You can also use placeholder variables when you specify conditions. For example, you can grant an IAM user permission to access a resource only if it is tagged with their IAM user name. For more information, see IAM policy elements: variables and tags in the IAM User Guide.

AWS supports global condition keys and service-specific condition keys. To see all AWS global condition keys, see AWS global condition context keys in the IAM User Guide.

Amazon MSK defines its own set of condition keys and also supports using some global condition keys. To see all AWS global condition keys, see AWS Global Condition Context Keys in the IAM User Guide.

To see a list of Amazon MSK condition keys, see Condition Keys for Amazon Managed Streaming for Apache Kafka in the IAM User Guide. To learn with which actions and resources you can use a condition key, see Actions Defined by Amazon Managed Streaming for Apache Kafka.

Examples

To view examples of Amazon MSK identity-based policies, see Amazon Managed Streaming for Apache Kafka Identity-Based Policy Examples.

Amazon MSK Resource-Based Policies

Amazon MSK does not support resource-based policies.

Authorization Based on Amazon MSK Tags

You can attach tags to Amazon MSK clusters. To control access based on tags, you provide tag information in the condition element of a policy using the kafka:ResourceTag/key-name, aws:RequestTag/key-name, or aws:TagKeys condition keys. For more information about tagging Amazon MSK resources, see Tagging an Amazon MSK Cluster.

To view an example identity-based policy for limiting access to a cluster based on the tags on that cluster, see Accessing Amazon MSK Clusters Based on Tags.

Amazon MSK IAM Roles

An IAM role is an entity within your AWS account that has specific permissions.

Using Temporary Credentials with Amazon MSK

You can use temporary credentials to sign in with federation, assume an IAM role, or to assume a cross-account role. You obtain temporary security credentials by calling AWS STS API operations such as AssumeRole or GetFederationToken.

Amazon MSK supports using temporary credentials.

Service-Linked Roles

Service-linked roles allow AWS services to access resources in other services to complete an action on your behalf. Service-linked roles appear in your IAM account and are owned by the service. An IAM administrator can view but not edit the permissions for service-linked roles.

Amazon MSK supports service-linked roles. For details about creating or managing Amazon MSK service-linked roles, Using Service-Linked Roles for Amazon MSK.