Services or capabilities described in Amazon Web Services documentation might vary by Region. To see the differences applicable to the China Regions, see Getting Started with Amazon Web Services in China (PDF).

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