Use proxy with Google.Cloud.Storage.V1

Hello team,

By design in our “on prem” datacenter we need to use a proxy to go though internet. We have been able to upload some file to our GCS without any proxy but we are stuck to upload a file when we need to use a proxy.

We use:

• .NET Core 2
• Windows Server 2016 to run our website

Where should we define the proxy in the API ? We didn’t find any way to do it ! Is it even possible ? We tried several ways but without success.

Code is very basic :

using (StreamReader r = new StreamReader("xxxx.json"))
            {
                string jsonFromStream = r.ReadToEnd();
                json = JsonConvert.DeserializeObject(jsonFromStream);
            }

            var credential = GoogleCredential.FromJson(json.ToString());
            var storageClient = StorageClient.Create(credential);
            storageClient.UploadObject("lr-xxxx-yyyy", "blogexample/image.png", null, image);

Thanks, Alexandre

[amanda-tarafa]

@liiri Google.Cloud.Logging.V2 works over gRPC not over HTTP so the way to set a proxy is different. There are two steps:

• For the credential, you use code just like the one above, i.e. create the credential with the HttpClientFactory that has a proxy set.

• Then, create the service client as follows (which will make all auth related requests go through the proxy):

            GoogleCredential proxiedCredential = ...; // Similar to above
            LoggingServiceV2ClientBuilder builder = new LoggingServiceV2ClientBuilder
            {
                TokenAccessMethod = (proxiedCredential as ITokenAccess).GetAccessTokenForRequestAsync
            };
            var loggingClient = builder.Build();
           // Use loggingClient normally.
  

• For gRPC requests (i.e. the actual logging requests) to use a proxy, then, you need to look at what Grpc.Core requieres. And that is to set any of a number of environment variables as described on the first point in gRPC environment variables docs. Also you might want to take a look at issues like https://github.com/grpc/grpc/issues/13323 and https://github.com/grpc/grpc/issues/12815 which are related. If you cannot make this part work, It’s better if you ask directly on https://github.com/grpc/grpc as we just rely on gRPC’s implementation for proxy setting.

[amanda-tarafa]

For posterity, we now have a better way to set a proxy for Google.Cloud.Storage.V1. If you are using Google.Cloud.Storage.V1 v3.5.0 (which is the latest at the moment of writing this) or an older version, you need to add an explicit dependency on Google.Api.Gax.Rest version 3.4.0.

IWebProxy proxy = ...;
Google.Apis.Http.HttpClientFactory factory = HttpClientFactory.ForProxy(proxy);

var scopes = new string[] { ... };
var credential= GoogleCredential.FromFile(sa_file); //Or any other way of obtaining the a Google credential
credential = credential.CreateScoped(scopes).CreateWithHttpClientFactory(factory);

var clientBuilder = new StorageClientBuilder
{
    Credential = credential,
    // All HTTP client instances for API calls will be obtained from this factory
    HttpClientFactory = factory
}

var client = clientBuilder.Build();

// Use client to perform Storage operations normally.