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    Get topic policy

    Gets the IAM policy associated with a topic.

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

    Code sample

    C++

    Before trying this sample, follow the C++ setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub C++ API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      namespace 
  
 iam 
  
 = 
  
 google 
 :: 
 cloud 
 :: 
 iam 
 ; 
 namespace 
  
 pubsub 
  
 = 
  
 google 
 :: 
 cloud 
 :: 
 pubsub 
 ; 
 []( 
 std 
 :: 
 string 
  
 project_id 
 , 
  
 std 
 :: 
 string 
  
 topic_id 
 ) 
  
 { 
  
 auto 
  
 const 
  
 topic 
  
 = 
  
 pubsub 
 :: 
 Topic 
 ( 
 std 
 :: 
 move 
 ( 
 project_id 
 ), 
  
 std 
 :: 
 move 
 ( 
 topic_id 
 )); 
  
 auto 
  
 client 
  
 = 
  
 iam 
 :: 
 IAMPolicyClient 
 ( 
  
 iam 
 :: 
 MakeIAMPolicyConnection 
 ( 
 pubsub 
 :: 
 IAMPolicyOptions 
 ())); 
  
 google 
 :: 
 iam 
 :: 
 v1 
 :: 
 GetIamPolicyRequest 
  
 request 
 ; 
  
 request 
 . 
 set_resource 
 ( 
 topic 
 . 
 FullName 
 ()); 
  
 auto 
  
 response 
  
 = 
  
 client 
 . 
 GetIamPolicy 
 ( 
 request 
 ); 
  
 if 
  
 ( 
 ! 
 response 
 ) 
  
 throw 
  
 std 
 :: 
 move 
 ( 
 response 
 ). 
 status 
 (); 
  
 std 
 :: 
 cout 
 << 
 "Policy for topic " 
 << 
 topic 
 . 
 FullName 
 () 
 << 
 ": " 
 << 
 response 
 - 
> DebugString 
 () 
 << 
 " 
 \n 
 " 
 ; 
 }

    C#

    Before trying this sample, follow the C# setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub C# API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      using 
  
  Google.Cloud.Iam.V1 
 
 ; 
 using 
  
  Google.Cloud.PubSub.V1 
 
 ; 
 public 
  
 class 
  
 GetTopicIamPolicySample 
 { 
  
 public 
  
 Policy 
  
 GetTopicIamPolicy 
 ( 
 string 
  
 projectId 
 , 
  
 string 
  
 topicId 
 ) 
  
 { 
  
  PublisherServiceApiClient 
 
  
 publisher 
  
 = 
  
  PublisherServiceApiClient 
 
 . 
  Create 
 
 (); 
  
  TopicName 
 
  
 topicName 
  
 = 
  
  TopicName 
 
 . 
  FromProjectTopic 
 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  Policy 
 
  
 policy 
  
 = 
  
 publisher 
 . 
  IAMPolicyClient 
 
 . 
 GetIamPolicy 
 ( 
 new 
  
  GetIamPolicyRequest 
 
  
 { 
  
 ResourceAsResourceName 
  
 = 
  
 topicName 
  
 }); 
  
 return 
  
 policy 
 ; 
  
 } 
 }

    Go

    Before trying this sample, follow the Go setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Go API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      import 
  
 ( 
  
 "context" 
  
 "fmt" 
  
 "io" 
  
 "cloud.google.com/go/iam/apiv1/iampb" 
  
 "cloud.google.com/go/pubsub/v2" 
 ) 
 func 
  
 getIAMPolicy 
 ( 
 w 
  
 io 
 . 
 Writer 
 , 
  
 projectID 
 , 
  
 topicID 
  
 string 
 ) 
  
 error 
  
 { 
  
 // projectID := "my-project-id" 
  
 // topicID := "my-topic" 
  
 ctx 
  
 := 
  
 context 
 . 
 Background 
 () 
  
 client 
 , 
  
 err 
  
 := 
  
 pubsub 
 . 
 NewClient 
 ( 
 ctx 
 , 
  
 projectID 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "pubsub.NewClient: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 defer 
  
 client 
 . 
 Close 
 () 
  
 req 
  
 := 
  
& iampb 
 . 
  GetIamPolicyRequest 
 
 { 
  
 Resource 
 : 
  
 fmt 
 . 
 Sprintf 
 ( 
 "projects/%s/topics/%s" 
 , 
  
 projectID 
 , 
  
 topicID 
 ), 
  
 } 
  
 policy 
 , 
  
 err 
  
 := 
  
 client 
 . 
 TopicAdminClient 
 . 
  GetIamPolicy 
 
 ( 
 ctx 
 , 
  
 req 
 ) 
  
 if 
  
 err 
  
 != 
  
 nil 
  
 { 
  
 return 
  
 fmt 
 . 
 Errorf 
 ( 
 "Policy: %w" 
 , 
  
 err 
 ) 
  
 } 
  
 for 
  
 _ 
 , 
  
 b 
  
 := 
  
 range 
  
 policy 
 . 
 Bindings 
  
 { 
  
 for 
  
 _ 
 , 
  
 m 
  
 := 
  
 range 
  
 b 
 . 
 Members 
  
 { 
  
 fmt 
 . 
 Fprintf 
 ( 
 w 
 , 
  
 "role: %s, member: %s\n" 
 , 
  
 b 
 . 
 Role 
 , 
  
 m 
 ) 
  
 } 
  
 } 
  
 return 
  
 nil 
 }

    Java

    Before trying this sample, follow the Java setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Java API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      import 
  
 com.google.cloud.pubsub.v1. TopicAdminClient 
 
 ; 
 import 
  
 com.google.iam.v1. GetIamPolicyRequest 
 
 ; 
 import 
  
 com.google.iam.v1. Policy 
 
 ; 
 import 
  
 com.google.pubsub.v1. TopicName 
 
 ; 
 import 
  
 java.io.IOException 
 ; 
 public 
  
 class 
 GetTopicPolicyExample 
  
 { 
  
 public 
  
 static 
  
 void 
  
 main 
 ( 
 String 
 ... 
  
 args 
 ) 
  
 throws 
  
 Exception 
  
 { 
  
 // TODO(developer): Replace these variables before running the sample. 
  
 String 
  
 projectId 
  
 = 
  
 "your-project-id" 
 ; 
  
 String 
  
 topicId 
  
 = 
  
 "your-topic-id" 
 ; 
  
 getTopicPolicyExample 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
 } 
  
 public 
  
 static 
  
 void 
  
 getTopicPolicyExample 
 ( 
 String 
  
 projectId 
 , 
  
 String 
  
 topicId 
 ) 
  
 throws 
  
 IOException 
  
 { 
  
 try 
  
 ( 
  TopicAdminClient 
 
  
 topicAdminClient 
  
 = 
  
  TopicAdminClient 
 
 . 
 create 
 ()) 
  
 { 
  
  TopicName 
 
  
 topicName 
  
 = 
  
  TopicName 
 
 . 
 of 
 ( 
 projectId 
 , 
  
 topicId 
 ); 
  
  GetIamPolicyRequest 
 
  
 getIamPolicyRequest 
  
 = 
  
  GetIamPolicyRequest 
 
 . 
 newBuilder 
 (). 
 setResource 
 ( 
 topicName 
 . 
  toString 
 
 ()). 
 build 
 (); 
  
  Policy 
 
  
 policy 
  
 = 
  
 topicAdminClient 
 . 
 getIamPolicy 
 ( 
 getIamPolicyRequest 
 ); 
  
 System 
 . 
 out 
 . 
 println 
 ( 
 "Topic policy: " 
  
 + 
  
 policy 
 ); 
  
 } 
  
 } 
 }

    Node.js

    Before trying this sample, follow the Node.js setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Node.js API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      /** 
 * TODO(developer): Uncomment this variable before running the sample. 
 */ 
 // 
  
 const 
  
 topicNameOrId 
  
 = 
  
 'YOUR_TOPIC_NAME_OR_ID' 
 ; 
 // 
  
 Imports 
  
 the 
  
 Google 
  
 Cloud 
  
 client 
  
 library 
 const 
  
 { 
 PubSub 
 } 
  
 = 
  
 require 
 ( 
 '@google-cloud/pubsub' 
 ); 
 // 
  
 Creates 
  
 a 
  
 client 
 ; 
  
 cache 
  
 this 
  
 for 
  
 further 
  
 use 
 const 
  
 pubSubClient 
  
 = 
  
 new 
  
 PubSub 
 (); 
 async 
  
 function 
  
 getTopicPolicy 
 ( 
 topicNameOrId 
 ) 
  
 { 
  
 // 
  
 Retrieves 
  
 the 
  
 IAM 
  
 policy 
  
 for 
  
 the 
  
 topic 
  
 const 
  
 [ 
 policy 
 ] 
  
 = 
  
 await 
  
 pubSubClient 
 . 
 topic 
 ( 
 topicNameOrId 
 ). 
 iam 
 . 
 getPolicy 
 (); 
  
 console 
 . 
 log 
 ( 
 'Policy for topic: %j.' 
 , 
  
 policy 
 . 
 bindings 
 ); 
 }

    Node.js

    Before trying this sample, follow the Node.js setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Node.js API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      /** 
 * 
 TODO 
 ( 
 developer 
 ): 
 Uncomment 
 this 
 variable 
 before 
 running 
 the 
 sample 
 . 
 */ 
 // 
 const 
 topicNameOrId 
 = 
 'YOUR_TOPIC_NAME_OR_ID' 
 ; 
 // 
 Imports 
 the 
 Google 
 Cloud 
 client 
 library 
 import 
  
 { 
 PubSub 
 , 
 Policy 
 } 
 from 
  
 '@google-cloud/pubsub' 
 ; 
 // 
 Creates 
 a 
 client 
 ; 
 cache 
 this 
 for 
 further 
 use 
 const 
 pubSubClient 
 = 
 new 
 PubSub 
 (); 
 async 
 function 
 getTopicPolicy 
 ( 
 topicNameOrId 
 : 
 string 
 ) 
 { 
 // 
 Retrieves 
 the 
 IAM 
 policy 
 for 
 the 
 topic 
 const 
 [ 
 policy 
 ]: 
 [ 
 Policy 
 ] 
 = 
 await 
 pubSubClient 
 . 
 topic 
 ( 
 topicNameOrId 
 ) 
 . 
 iam 
 . 
 getPolicy 
 (); 
 console 
 . 
 log 
 ( 
 'Policy for topic: %j.' 
 , 
 policy 
 . 
 bindings 
 ); 
 }

    PHP

    Before trying this sample, follow the PHP setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub PHP API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      use Google\Cloud\PubSub\PubSubClient; 
 /** 
 * Prints the policy for a Pub/Sub topic. 
 * 
 * @param string $projectId  The Google project ID. 
 * @param string $topicName  The Pub/Sub topic name. 
 */ 
 function get_topic_policy($projectId, $topicName) 
 { 
 $pubsub = new PubSubClient([ 
 'projectId' => $projectId, 
 ]); 
 $topic = $pubsub->topic($topicName); 
 $policy = $topic->iam()->policy(); 
 print_r($policy); 
 }

    Python

    Before trying this sample, follow the Python setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Python API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      from 
  
 google.cloud 
  
 import 
 pubsub_v1 
 # TODO(developer): Choose an existing topic. 
 # project_id = "your-project-id" 
 # topic_id = "your-topic-id" 
 client 
 = 
 pubsub_v1 
 . 
  PublisherClient 
 
 () 
 topic_path 
 = 
 client 
 . 
 topic_path 
 ( 
 project_id 
 , 
 topic_id 
 ) 
 policy 
 = 
 client 
 . 
 get_iam_policy 
 ( 
 request 
 = 
 { 
 "resource" 
 : 
 topic_path 
 }) 
 print 
 ( 
 "Policy for topic 
 {} 
 :" 
 . 
 format 
 ( 
 topic_path 
 )) 
 for 
 binding 
 in 
 policy 
 . 
 bindings 
 : 
 print 
 ( 
 "Role: 
 {} 
 , Members: 
 {} 
 " 
 . 
 format 
 ( 
 binding 
 . 
 role 
 , 
 binding 
 . 
 members 
 ))

    Ruby

    Before trying this sample, follow the Ruby setup instructions in the Pub/Sub quickstart using client libraries . For more information, see the Pub/Sub Ruby API reference documentation .

    To authenticate to Pub/Sub, set up Application Default Credentials. For more information, see Set up authentication for a local development environment .

      # topic_id = "your-topic-id" 
 pubsub 
  
 = 
  
 Google 
 :: 
 Cloud 
 :: 
  PubSub 
 
 . 
  new 
 
 policy 
  
 = 
  
 pubsub 
 . 
  iam 
 
 . 
 get_iam_policy 
  
 resource 
 : 
  
 pubsub 
 . 
 topic_path 
 ( 
 topic_id 
 ) 
 puts 
  
 "Topic policy:" 
 puts 
  
 policy 
 . 
 bindings 
 . 
 first 
 . 
 role

    What's next

    To search and filter code samples for other Google Cloud products, see the Google Cloud sample browser .
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