Client authentication using OAuth 2.0 access tokens

Pulsar supports authenticating clients using OAuth 2.0 access tokens. You can use OAuth 2.0 access tokens to identify a Pulsar client and associate the Pulsar client with some "principal" (or "role"), which is permitted to do some actions, such as publishing messages to a topic or consume messages from a topic.

This module is used to support the Pulsar client authentication plugin for OAuth 2.0. After communicating with the Oauth 2.0 server, the Pulsar client gets an access token from the Oauth 2.0 server, and passes this access token to the Pulsar broker to do the authentication. The broker can use the org.apache.pulsar.broker.authentication.AuthenticationProviderToken. Or, you can add your own AuthenticationProvider to make it with this module.

Authentication provider configuration

This library allows you to authenticate the Pulsar client by using an access token that is obtained from an OAuth 2.0 authorization service, which acts as a token issuer.

Authentication types

The authentication type determines how to obtain an access token through an OAuth 2.0 authorization flow.

Note

Currently, the Pulsar Java client only supports the client_credentials authentication type.

Client credentials

The following table lists parameters supported for the client credentials authentication type.

Parameter	Description	Example	Required or not
type	Oauth 2.0 authentication type.	client_credentials (default)	Optional
issuerUrl	URL of the authentication provider which allows the Pulsar client to obtain an access token	https://accounts.google.com	Required
privateKey	URL to a JSON credentials file	Support the following pattern formats: file:///path/to/file file:/path/to/file data:application/json;base64,<base64-encoded value>	Required
audience	An OAuth 2.0 "resource server" identifier for the Pulsar cluster	https://broker.example.com	Required

The credentials file contains service account credentials used with the client authentication type. The following shows an example of a credentials file credentials_file.json.

{
  "type": "client_credentials",
  "client_id": "d9ZyX97q1ef8Cr81WHVC4hFQ64vSlDK3",
  "client_secret": "on1uJ...k6F6R",
  "client_email": "1234567890-abcdefghijklmnopqrstuvwxyz@developer.gserviceaccount.com",
  "issuer_url": "https://accounts.google.com"
}

In the above example, the authentication type is set to client_credentials by default. And the fields "client_id" and "client_secret" are required.

Typical original Oauth2 request mapping

The following shows a typical original Oauth2 request, which is used to obtain the access token from the Oauth2 server.

curl --request POST \
  --url https://dev-kt-aa9ne.us.auth0.com/oauth/token \
  --header 'content-type: application/json' \
  --data '{
  "client_id":"Xd23RHsUnvUlP7wchjNYOaIfazgeHd9x",
  "client_secret":"rT7ps7WY8uhdVuBTKWZkttwLdQotmdEliaM5rLfmgNibvqziZ-g07ZH52N_poGAb",
  "audience":"https://dev-kt-aa9ne.us.auth0.com/api/v2/",
  "grant_type":"client_credentials"}'

In the above example, the mapping relationship is shown as below.

• The issuerUrl parameter in this plugin is mapped to --url https://dev-kt-aa9ne.us.auth0.com/oauth/token.
• The privateKey file parameter in this plugin should at least contains the client_id and client_secret fields.
• The audience parameter in this plugin is mapped to "audience":"https://dev-kt-aa9ne.us.auth0.com/api/v2/".

Client Configuration

You can use the Oauth2 authentication provider with the following Pulsar clients.

Java

You can use the factory method to configure authentication for Pulsar Java client.

import org.apache.pulsar.client.impl.auth.oauth2.AuthenticationFactoryOAuth2;

String issuerUrl = "https://dev-kt-aa9ne.us.auth0.com/oauth/token";
String credentialsUrl = "file:///path/to/KeyFile.json";
String audience = "https://dev-kt-aa9ne.us.auth0.com/api/v2/";

PulsarClient client = PulsarClient.builder()
    .serviceUrl("pulsar://broker.example.com:6650/")
    .authentication(
        AuthenticationFactoryOAuth2.clientCredentials(issuerUrl, credentialsUrl, audience))
    .build();

In addition, you can also use the encoded parameters to configure authentication for Pulsar Java client.

Authentication auth = AuthenticationFactory
    .create(AuthenticationOAuth2.class.getName(), "{"type":"client_credentials","privateKey":"./key/path/..","issuerUrl":"...","audience":"..."}");
PulsarClient client = PulsarClient.builder()
    .serviceUrl("pulsar://broker.example.com:6650/")
    .authentication(auth)
    .build();

C++ client

The C++ client is similar to the Java client. You need to provide parameters of issuerUrl, private_key (the credentials file path), and the audience.

#include <pulsar/Client.h>

pulsar::ClientConfiguration config;
std::string params = R"({
    "issuer_url": "https://dev-kt-aa9ne.us.auth0.com/oauth/token",
    "private_key": "../../pulsar-broker/src/test/resources/authentication/token/cpp_credentials_file.json",
    "audience": "https://dev-kt-aa9ne.us.auth0.com/api/v2/"})";

config.setAuth(pulsar::AuthOauth2::create(params));

pulsar::Client client("pulsar://broker.example.com:6650/", config);

Go client

To enable OAuth2 authentication in Go client, you need to configure OAuth2 authentication. This example shows how to configure OAuth2 authentication in Go client.

oauth := pulsar.NewAuthenticationOAuth2(map[string]string{
		"type":       "client_credentials",
		"issuerUrl":  "https://dev-kt-aa9ne.us.auth0.com/oauth/token",
		"audience":   "https://dev-kt-aa9ne.us.auth0.com/api/v2/",
		"privateKey": "/path/to/privateKey",
		"clientId":   "0Xx...Yyxeny",
	})
client, err := pulsar.NewClient(pulsar.ClientOptions{
		URL:              "puslar://my-cluster:6650",
		Authentication:   oauth,
})

Python client

To enable OAuth2 authentication in Python client, you need to configure OAuth2 authentication. This example shows how to configure OAuth2 authentication in Python client.

from pulsar import Client, AuthenticationOauth2

params = '''
{
    "issuer_url": "https://dev-kt-aa9ne.us.auth0.com",
    "private_key": "/path/to/privateKey",
    "audience": "https://dev-kt-aa9ne.us.auth0.com/api/v2/"
}
'''

client = Client("puslar://my-cluster:6650", authentication=AuthenticationOauth2(params))