How Amazon EMR Works with IAM

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 EMR 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.

Amazon EMR does not support resource-based policies.

Actions

The Action element of an IAM identity-based policy describes the specific action or actions that will be allowed or denied by the policy. Policy actions usually have the same name as the associated AWS API operation. The action is used in a policy to grant permissions to perform the associated operation.

Policy actions in Amazon EMR use the following prefix before the action: elasticmapreduce:. For example, to grant someone permission to create a cluster using the RunJobFlow API operation, you include the elasticmapreduce:RunJobFlow action in their policy. Policy statements must include either an Action or NotAction element. Amazon EMR 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": [
      "elasticmapreduce:action1",
      "elasticmapreduce: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": "elasticmapreduce:Describe*"

To see a list of Amazon EMR actions, see Actions Defined by Amazon EMR in the IAM User Guide.

Resources

The Resource element specifies the object or objects to which the action applies. Statements must include either a Resource or a NotResource element. You specify a resource using an ARN or using the wildcard (*) to indicate that the statement applies to all resources.

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

Condition Keys

The Condition element (or Condition block) lets you specify conditions in which a statement is in effect. The Condition element is optional. You can build 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.

Amazon EMR 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.

All Amazon EC2 actions support the aws:RequestedRegion and ec2:Region condition keys. For more information, see Example: Restricting Access to a Specific Region.

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

Use Cluster and Notebook Tags with IAM Policies for Access Control

Permission for Amazon EMR actions associated with EMR Notebooks and EMR clusters can be fine-tuned using tag-based access control with identity-based IAM policies. You can use condition keys within a Condition element (also called a Condition block) to allow certain actions only when a notebook, cluster, or both has a certain tag key or key-value combination. You can also limit the CreateEditor action (which creates an EMR notebook) and the RunJobFlow action (which creates a cluster) so that a request for a tag must be submitted when the resource is created.

In Amazon EMR, the condition keys that can be used in a Condition element apply only to those Amazon EMR API actions where ClusterID or NotebookID is a required request parameter. For example, the ModifyInstanceGroups action does not support context keys because ClusterID is an optional parameter.

When you create an EMR notebook, a default tag is applied with a key string of creatorUserId set to the value of the IAM User ID who created the notebook. This is useful for limiting allowed actions for the notebook only to the creator.

The following condition keys are available in Amazon EMR:

• Use the elasticmapreduce:ResourceTag/TagKeyString condition context key to allow or deny user actions on clusters or notebooks with tags that have the TagKeyString that you specify. If an action passes both ClusterID and NotebookID, the condition applies to both the cluster and the notebook. This means that both resources must have the tag key string or key-value combination that you specify. You can use the Resource element to limit the statement so that it applies only to clusters or notebooks as required. For more information, see Amazon EMR Identity-Based Policy Examples.

• Use the elasticmapreduce:RequestTag/TagKeyString condition context key to require a specific tag with actions/API calls. For example, you can use this condition context key along with the CreateEditor action to require that a key with TagKeyString is applied to a notebook when it is created.

Understanding the EMR Cluster VisibleToAllUsers Setting

VisibleToAllUsers is a cluster setting unique to Amazon EMR that works in conjunction with IAM policies. When this setting is true, it indicates that IAM users in the AWS account can perform actions associated with EMR that their IAM policy allows. If set to false, only the IAM user that created the cluster (in addition to the AWS account root user) can perform EMR actions.

When you create a cluster using the console, the default value is true. You can use advanced cluster creation options to modify the setting by selecting or clearing the Cluster visible to all IAM users in account setting on the Security page.

When you create a cluster using the Amazon EMR API or the AWS CLI, the value defaults to false unless it is provided. When using the AWS CLI to create a cluster, use the --visible-to-all-users or --no-visible-to-all-users options of the emr create-cluster command to set the value to true or false respectively. When using the Amazon EMR API to create a cluster, use the VisibleToAllUsers property of the RunJobFlow action to set the value.

On a running cluster that has VisibleToAllUsers set to false, only the IAM user that created the cluster and the AWS account root user can change the setting. If VisibleToAllUsers is set to true, IAM users who are allowed to use the SetVisibleToAllUsers action can change the setting. The SetVisibleToAllUsers action of the Amazon EMR API or the AWS CLI emr modify-cluster-attributes command with the --visible-to-all-users and --no-visible-to-all-users options must be used to change the value to true if the cluster was created with the value set to false. It cannot be changed using the console.

Examples

To view examples of Amazon EMR identity-based policies, see Amazon EMR Identity-Based Policy Examples.