Can OAuth2 be used in Google Cloud Client Libraries?

Question

• I would like to use .net variant of Google Cloud Client Libraries (Resource Manager for creating new project, for example).
• I wouldn't like to use neither service account credentials nor ADC.

Can I somehow pass existing OAuth credentials (access token, obtained for appropriate scope) to the client library to authenticate the given user? (Or) do I need any authentication client library?

Briefly looked at the ProjectsClientBuilder class, but seems heavy generated (also as the documentation), meaning it's a bit harder to find any hint.

Answer 1

The following example shows how to authorize the Google cloud resource manager API using Oauth2 for an installed app.

// Key file from google developer console (INSTALLED APP)
var PathToInstalledKeyFile = @"C:\Development\FreeLance\GoogleSamples\Credentials\credentials.json";

// scope of authorization needed for the method in question.
var scopes = "https://www.googleapis.com/auth/cloud-platform";

// Installed app authorizaton.
var credential = GoogleWebAuthorizationBroker.AuthorizeAsync(GoogleClientSecrets.FromFile(PathToInstalledKeyFile).Secrets,
    new []{  scopes },
    "userName",
    CancellationToken.None,
    new FileDataStore("usercreds", true)).Result;

var client = new ProjectsClientBuilder()
{
    Credential = credential,
}.Build();

var projects = client.ListProjects(new FolderName("123"));

Note for a web application the code will be different. Web authorization is not the same with the client library. I havent tried to connect any of the cloud apis via web oauth before.