Get an IAM policy

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Demonstrates retrieving an IAM policy.

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For detailed documentation that includes this code sample, see the following:

Code sample

C#

To learn how to install and use the client library for IAM, see IAM client libraries. For more information, see the IAM C# API reference documentation.


using Google.Apis.Auth.OAuth2;
using Google.Apis.CloudResourceManager.v1;
using Google.Apis.CloudResourceManager.v1.Data;

public partial class AccessManager
{
    public static Policy GetPolicy(string projectId)
    {
        var credential = GoogleCredential.GetApplicationDefault()
            .CreateScoped(CloudResourceManagerService.Scope.CloudPlatform);
        var service = new CloudResourceManagerService(
            new CloudResourceManagerService.Initializer
            {
                HttpClientInitializer = credential
            });

        var policy = service.Projects.GetIamPolicy(new GetIamPolicyRequest(),
            projectId).Execute();
        return policy;
    }
}

C++

To learn how to install and use the client library for IAM, see IAM client libraries. For more information, see the IAM C++ API reference documentation.

namespace iam = ::google::cloud::iam;
[](std::string const& name) {
  iam::IAMClient client(iam::MakeIAMConnection());
  auto response = client.GetIamPolicy(name);
  if (!response) throw std::runtime_error(response.status().message());
  std::cout << "Policy successfully retrieved: " << response->DebugString()
            << "\n";
}

Java

To learn how to install and use the client library for IAM, see IAM client libraries. For more information, see the IAM Java API reference documentation.

import com.google.api.client.googleapis.javanet.GoogleNetHttpTransport;
import com.google.api.client.json.jackson2.JacksonFactory;
import com.google.api.services.cloudresourcemanager.v3.CloudResourceManager;
import com.google.api.services.cloudresourcemanager.v3.model.GetIamPolicyRequest;
import com.google.api.services.cloudresourcemanager.v3.model.Policy;
import com.google.api.services.iam.v1.IamScopes;
import com.google.auth.http.HttpCredentialsAdapter;
import com.google.auth.oauth2.GoogleCredentials;
import java.io.IOException;
import java.security.GeneralSecurityException;
import java.util.Collections;

public class GetPolicy {

  // Gets a project's policy.
  public static Policy getPolicy(String projectId) {
    // projectId = "my-project-id"

    Policy policy = null;

    CloudResourceManager service = null;
    try {
      service = createCloudResourceManagerService();
    } catch (IOException | GeneralSecurityException e) {
      System.out.println("Unable to initialize service: \n" + e.toString());
      return policy;
    }

    try {
      GetIamPolicyRequest request = new GetIamPolicyRequest();
      policy = service.projects().getIamPolicy(projectId, request).execute();
      System.out.println("Policy retrieved: " + policy.toString());
      return policy;
    } catch (IOException e) {
      System.out.println("Unable to get policy: \n" + e.toString());
      return policy;
    }
  }

  public static CloudResourceManager createCloudResourceManagerService()
      throws IOException, GeneralSecurityException {
    // Use the Application Default Credentials strategy for authentication. For more info, see:
    // https://cloud.google.com/docs/authentication/production#finding_credentials_automatically
    GoogleCredentials credential =
        GoogleCredentials.getApplicationDefault()
            .createScoped(Collections.singleton(IamScopes.CLOUD_PLATFORM));

    CloudResourceManager service =
        new CloudResourceManager.Builder(
                GoogleNetHttpTransport.newTrustedTransport(),
                JacksonFactory.getDefaultInstance(),
                new HttpCredentialsAdapter(credential))
            .setApplicationName("service-accounts")
            .build();
    return service;
  }
}

Python

To learn how to install and use the client library for IAM, see IAM client libraries. For more information, see the IAM Python API reference documentation.

def get_policy(project_id, version=1):
    """Gets IAM policy for a project."""

    credentials = service_account.Credentials.from_service_account_file(
        filename=os.environ["GOOGLE_APPLICATION_CREDENTIALS"],
        scopes=["https://www.googleapis.com/auth/cloud-platform"],
    )
    service = googleapiclient.discovery.build(
        "cloudresourcemanager", "v1", credentials=credentials
    )
    policy = (
        service.projects()
        .getIamPolicy(
            resource=project_id,
            body={"options": {"requestedPolicyVersion": version}},
        )
        .execute()
    )
    print(policy)
    return policy

What's next

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