Connect to cluster through C++ client

This document describes how to connect to a cluster through a C++ client, and use the C++ producer and consumer to produce and consume messages to and from a topic. The Java client supports to connect to a Pulsar cluster either through the Oauth2 authentication plugin or Token authentication plugin.

Connect to cluster through OAuth2 authentication plugin

To connect a cluster through the OAuth2 authentication plugin, follow these steps.

1. Get the service URL of your Pulsar cluster. For details, see get a service URL.

2. Get the OAuth2 credential file of your service account. For details, see get an OAuth2 credential file.

3. Connect to a Pulsar cluster through the OAuth2 authentication plugin.

   int main() {
     ClientConfiguration config;
     std::string oauthParams = R"({
     "issuer_url": "https://auth.streamnative.cloud",
     "private_key": "file:///absolute path/to/key/file.json",
     "audience": "https://cloud.auth0.com/api/v2/"})";
   
     config.setAuth(pulsar::AuthOauth2::create(oauthParams));
   
     Client client("broker-service-url", config);
     client.close();
   }
   

   • issuerUrl: the URL of your OAuth2 authentication provider. You can get the value from your downloaded OAuth2 credential file.
   • private_key: the path to your downloaded OAuth2 credential file. The privateKey parameter supports the following three pattern formats:
     • file:///path/to/file
     • file:/path/to/file
     • data:application/json;base64,<base64-encoded value>
   • audience: the audience parameter is the Uniform Resource Name (URN), which is a combination of the urn:sn:pulsar, the organization name, and the Pulsar instance name, in this format urn:sn:pulsar:<org_name>:<instance_name>.
   • broker-service-url: the broker service URL of your Pulsar cluster.

4. Create a C++ consumer and use the C++ consumer to consume messages.

   int main(int argc, char *argv[]) {
     ClientConfiguration config;
     std::string oauthParams = argv[2];
   
     config.setAuth(pulsar::AuthOauth2::create(oauthParams));
   
     Client client(argv[1], config);
   
     Consumer consumer;
     Result result = client.subscribe("persistent://public/default/my-topic", "consumer-1", consumer);
     if (result != ResultOk) {
       std::cout << "Failed to subscribe: " << result << "\n";
       return -1;
     }
   
     Message msg;
     while (true) {
       consumer.receive(msg);
       std::cout << "Received: " << msg << "  with payload '" << msg.getDataAsString() << "'" << "\n";
   
       consumer.acknowledge(msg);
     }
   }
   

5. Create a C++ producer and use the C++ producer to produce messages.

   int main(int argc, char *argv[]) {
     ClientConfiguration config;
     std::string oauthParams = argv[2];
   
     config.setAuth(pulsar::AuthOauth2::create(oauthParams));
   
     Client client(argv[1], config);
   
     Producer producer;
     Result result = client.createProducer("persistent://public/default/my-topic", producer);
     if (result != ResultOk) {
       std::cout << "Error creating producer: " << result << "\n";
       return -1;
     }
   
     // Send synchronously
     Message msg = MessageBuilder().setContent("content").build();
     Result res = producer.send(msg);
     std::cout << "Message sent: " << res << "\n";
   
     client.close();
   }
   

Connect to cluster through Token authentication plugin

To connect a cluster through the Token authentication plugin, follow these steps.

1. Get the service URL of your Pulsar cluster. For details, see get a service URL.

2. Get the token of your service account. For details, see get a token.

3. Connect to a Pulsar cluster through the Token authentication plugin.

   int main() {
     ClientConfiguration config;
     config.setAuth(AuthToken::create("AUTH_PARAMS"));
     Client client(SERVICE_URL, config);
   
     client.close();
   }
   

   • SERVICE_URL: the broker service URL of your Pulsar cluster.
   • AUTH_PARAMS: the token of your service account.

For a complete example about how to connect to a cluster through the Pulsar C++ client, see C++ client examples.