Can't resolve metadata server in ComputeTokenUrl

[MricMoho]

Hi,

I have actually some servers in compute engine and i wanted to the use ComputeCredential to create my client but I get an error because the host "metadata" can't be resolved:

        public const string ComputeTokenUrl =
            "http://metadata/computeMetadata/v1/instance/service-accounts/default/token";

https://github.com/google/google-api-dotnet-client/blob/master/Src/Support/Google.Apis.Auth/OAuth2/GoogleAuthConsts.cs

It should not be "metadata.google.internal" instead?
Or directly the IP like you did in last realease in the ComputeCredential class?
public const string MetadataServerUrl = "http://169.254.169.254"; // IP address instead of name to avoid DNS resolution
https://github.com/google/google-api-dotnet-client/pull/1158/files

[jskeet]

Could you give me more background about how you're running into this?

• What platform within Compute Engine are you running on? (Is this plain GCE with a VM, and if so, what kind of VM? Or is it Kubernetes Engine etc?)
• What code are you using at the moment? Are you fetching the default credentials, or something else?

[MricMoho]

Yes, it's a plain GCE with a VM, running on Windows Server 2012 R2 Datacenter.

Type de machine
n1-standard-2 :2 vCPU, 7,5 Go de mémoire
Plate-forme du processeur
Intel Haswell
Zone
europe-west1-d

I am fetching them using GetApplicationDefault()

        static void Main(string[] args)
        {
            GoogleCredential credentials = Google.Apis.Auth.OAuth2.GoogleCredential.GetApplicationDefault();
            try
            {
                var client = StorageClient.Create(credentials);

                var testFile = new StreamReader("test.png");
                client.UploadObject("bucketname", "test.png", "image/png", testFile.BaseStream);
                Console.WriteLine("all ok");
            }
            catch (Exception e)
            {
                Console.WriteLine(e.Message);
                Console.WriteLine(e.InnerException);
            }
        }

[jskeet]

As an aside, if you call StorageClient.Create(), that will use the application default credentials for you, so your code can be simplified further :)

However, for the moment, if you know you're running on GCE, you could try this workaround:

var url = "http://169.254.169.254/computeMetadata/v1/instance/service-accounts/default/token";
var initializer = new ComputeCredential.Initializer(url);
var credential = new ComputeCredential(initializer);

Then pass that to StorageClient.Create. That would give us a good idea of whether the URL is really the problem.

[MricMoho]

Thx for the workaround.
Works fine with that

[jskeet]

Great - in that case, I'll leave this issue open for now, and we can modify that constant.