Work with IAM policies - AWS SDK for Java 2.x
Create a policyGet a policyAttach a role policyList attached role policiesDetach a role policyMore information

Work with IAM policies

Create a policy

To create a new policy, provide the policy’s name and a JSON-formatted policy document in a CreatePolicyRequest to the IamClient’s createPolicy method.

Imports 

import software.amazon.awssdk.core.waiters.WaiterResponse;
import software.amazon.awssdk.services.iam.model.CreatePolicyRequest;
import software.amazon.awssdk.services.iam.model.CreatePolicyResponse;
import software.amazon.awssdk.services.iam.model.GetPolicyRequest;
import software.amazon.awssdk.services.iam.model.GetPolicyResponse;
import software.amazon.awssdk.services.iam.model.IamException;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
import software.amazon.awssdk.services.iam.waiters.IamWaiter;

Code 

    public static String createIAMPolicy(IamClient iam, String policyName ) {

        try {
            // Create an IamWaiter object
            IamWaiter iamWaiter = iam.waiter();

            CreatePolicyRequest request = CreatePolicyRequest.builder()
                .policyName(policyName)
                .policyDocument(PolicyDocument).build();

            CreatePolicyResponse response = iam.createPolicy(request);

            // Wait until the policy is created
            GetPolicyRequest polRequest = GetPolicyRequest.builder()
                    .policyArn(response.policy().arn())
                    .build();

            WaiterResponse<GetPolicyResponse> waitUntilPolicyExists = iamWaiter.waitUntilPolicyExists(polRequest);
            waitUntilPolicyExists.matched().response().ifPresent(System.out::println);
            return response.policy().arn();

         } catch (IamException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
        return "" ;
    }

See the complete example on GitHub.

Get a policy

To retrieve an existing policy, call the IamClient’s getPolicy method, providing the policy’s ARN within a GetPolicyRequest object.

Imports 

import software.amazon.awssdk.services.iam.model.GetPolicyRequest;
import software.amazon.awssdk.services.iam.model.GetPolicyResponse;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
import software.amazon.awssdk.services.iam.model.IamException;

Code 

    public static void getIAMPolicy(IamClient iam, String policyArn) {

        try {
            GetPolicyRequest request = GetPolicyRequest.builder()
                .policyArn(policyArn).build();

            GetPolicyResponse response = iam.getPolicy(request);
            System.out.format("Successfully retrieved policy %s",
                response.policy().policyName());

        } catch (IamException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

See the complete example on GitHub.

Attach a role policy

You can attach a policy to an IAM role by calling the IamClient’s attachRolePolicy method, providing it with the role name and policy ARN in an AttachRolePolicyRequest.

Imports 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
import software.amazon.awssdk.services.iam.model.IamException;
import software.amazon.awssdk.services.iam.model.AttachRolePolicyRequest;
import software.amazon.awssdk.services.iam.model.AttachedPolicy;
import software.amazon.awssdk.services.iam.model.ListAttachedRolePoliciesRequest;
import software.amazon.awssdk.services.iam.model.ListAttachedRolePoliciesResponse;
import java.util.List;

Code 

    public static void attachIAMRolePolicy(IamClient iam, String roleName, String policyArn ) {

        try {

             ListAttachedRolePoliciesRequest request = ListAttachedRolePoliciesRequest.builder()
                    .roleName(roleName)
                    .build();

            ListAttachedRolePoliciesResponse  response = iam.listAttachedRolePolicies(request);
            List<AttachedPolicy> attachedPolicies = response.attachedPolicies();

            // Ensure that the policy is not attached to this role
            String polArn = "";
            for (AttachedPolicy policy: attachedPolicies) {
                polArn = policy.policyArn();
                if (polArn.compareTo(policyArn)==0) {
                   System.out.println(roleName +
                            " policy is already attached to this role.");
                    return;
                }
          }

            AttachRolePolicyRequest attachRequest =
                AttachRolePolicyRequest.builder()
                        .roleName(roleName)
                        .policyArn(policyArn)
                        .build();

            iam.attachRolePolicy(attachRequest);

            System.out.println("Successfully attached policy " + policyArn +
                " to role " + roleName);

         } catch (IamException e) {
                System.err.println(e.awsErrorDetails().errorMessage());
                System.exit(1);
          }

     System.out.println("Done");
    }

See the complete example on GitHub.

List attached role policies

List attached policies on a role by calling the IamClient’s listAttachedRolePolicies method. It takes a ListAttachedRolePoliciesRequest object that contains the role name to list the policies for.

Call getAttachedPolicies on the returned ListAttachedRolePoliciesResponse object to get the list of attached policies. Results may be truncated; if the ListAttachedRolePoliciesResponse object’s isTruncated method returns true, call the ListAttachedRolePoliciesResponse object’s marker method. Use the marker returned to create a new request and use it to call listAttachedRolePolicies again to get the next batch of results.

Imports 

import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
import software.amazon.awssdk.services.iam.model.IamException;
import software.amazon.awssdk.services.iam.model.AttachRolePolicyRequest;
import software.amazon.awssdk.services.iam.model.AttachedPolicy;
import software.amazon.awssdk.services.iam.model.ListAttachedRolePoliciesRequest;
import software.amazon.awssdk.services.iam.model.ListAttachedRolePoliciesResponse;
import java.util.List;

Code 

    public static void attachIAMRolePolicy(IamClient iam, String roleName, String policyArn ) {

        try {

             ListAttachedRolePoliciesRequest request = ListAttachedRolePoliciesRequest.builder()
                    .roleName(roleName)
                    .build();

            ListAttachedRolePoliciesResponse  response = iam.listAttachedRolePolicies(request);
            List<AttachedPolicy> attachedPolicies = response.attachedPolicies();

            // Ensure that the policy is not attached to this role
            String polArn = "";
            for (AttachedPolicy policy: attachedPolicies) {
                polArn = policy.policyArn();
                if (polArn.compareTo(policyArn)==0) {
                   System.out.println(roleName +
                            " policy is already attached to this role.");
                    return;
                }
          }

            AttachRolePolicyRequest attachRequest =
                AttachRolePolicyRequest.builder()
                        .roleName(roleName)
                        .policyArn(policyArn)
                        .build();

            iam.attachRolePolicy(attachRequest);

            System.out.println("Successfully attached policy " + policyArn +
                " to role " + roleName);

         } catch (IamException e) {
                System.err.println(e.awsErrorDetails().errorMessage());
                System.exit(1);
          }

     System.out.println("Done");
    }

See the complete example on GitHub.

Detach a role policy

To detach a policy from a role, call the IamClient’s detachRolePolicy method, providing it with the role name and policy ARN in a DetachRolePolicyRequest.

Imports 

import software.amazon.awssdk.services.iam.model.DetachRolePolicyRequest;
import software.amazon.awssdk.regions.Region;
import software.amazon.awssdk.services.iam.IamClient;
import software.amazon.awssdk.services.iam.model.IamException;

Code 

    public static void detachPolicy(IamClient iam, String roleName, String policyArn ) {

        try {
            DetachRolePolicyRequest request = DetachRolePolicyRequest.builder()
                    .roleName(roleName)
                    .policyArn(policyArn)
                    .build();

            iam.detachRolePolicy(request);
            System.out.println("Successfully detached policy " + policyArn +
                " from role " + roleName);

        } catch (IamException e) {
            System.err.println(e.awsErrorDetails().errorMessage());
            System.exit(1);
        }
    }

See the complete example on GitHub.

More information