如何使用凭证 json 文件连接到 google pubsub

Question

我需要编写一个函数来使用包含凭证详细信息（从秘密管理器获得）的 json 文件将消息发布到 google pubsub。

**公共异步任务 PublisMessage（ApiRequestHeaders MetaData，PubSubRequest pubSubModel）{字符串 jsonPath = Environment.GetEnvironmentVariable（“GOOGLE_APPLICATION_CREDENTIALS”）；

GoogleCredential googleCredential = null;
using (var jsonStream = new FileStream(jsonPath, FileMode.Open,
    FileAccess.Read, FileShare.Read))
{
    googleCredential = GoogleCredential.FromStream(jsonStream);
}

var createSettings = new PublisherClient.ClientCreationSettings(credentials: googleCredential.ToChannelCredentials());

TopicName topicName = new TopicName(pubSubModel.ProjectId, pubSubModel.TopicName);
try
{
    
    PublisherClient _publisher = await PublisherClient.CreateAsync(topicName,
    clientCreationSettings: createSettings);
    var _message = await GetPublisMessage(pubSubModel.DocumentId, MetaData);
    var acknowledgmentNumber = await _publisher.PublishAsync(_message); //Permission denied error
    
    return true;
}
catch (Exception ex)
{
    _logger.Error("PushMessageToPubsub  Error : " + ex);
    return false;
}

**