Call to load credentials with FirebaseAdmin does not work

Usually I post my issues on stack exchange, because I’m assuming the problem is mine. So I’ve done that…

But It occurs to me that on this one maybe I should log a bug. Sure seems to be one. So here’s what I wrote…

I am working with FirebaseAdmin 1.9.1 and attempting to use the recommended method for this call:

FirebaseApp.Create(new AppOptions()  
{
  Credential = credential,
});

From all that I read, I can load the credential paramater via this…

var credential = await GoogleCredential.GetApplicationDefaultAsync();

or this

credential = GoogleCredential.FromFile("/your/path/to/glory/google-service-accounts.json");

And if the value of a special environment variable is set as so…

"GOOGLE_APPLICATION_CREDENTIALS": "/your/path/to/glory/google-service-accounts.json",

…the two approaches should produce the same, working, result.

Not so! Not so.

The 2nd version works, but the first, recommended, approach? Using GetApplicationDefaultAsync?

Not so much.

I have checked and re-checked, and the two strings containing “/your/path/to/glory/google-service-accounts.json” are identical, though obviously not the value I’ve pasted here.

GOOGLE_APPLICATION_CREDENTIALS I copied and pasted directly. And I can see it properly set in the environment variables.

In fact, just to add salt to my wounds, I tried this…

credential = GoogleCredential.FromFile(_configuration["GOOGLE_APPLICATION_CREDENTIALS"]);

And the credentials DID load.

[WellspringCS]

Cutting to the point: I did scrutinize that code yesterday, asking the same question. But (in a longer paragraph I started to write to you this morning, I realized I was telling you that GOOGLE_APPLICATION_CREDENTIALS was coming in via secrets.

Ooops. That’s not environment.

I moved it and… problem solved. Thanks much!

[hiranya911]

You can see here that the first thing it does is to look up the GOOGLE_APPLICATION_CREDENTIALS env variable:

https://github.com/googleapis/google-api-dotnet-client/blob/master/Src/Support/Google.Apis.Auth/OAuth2/DefaultCredentialProvider.cs#L84

My guess is that your env variable is not set correctly (or it is not set in a way that is visible to your running process). This causes it to fallback to one of the other credential discovery mechanisms, and ends up finding the wrong credentials.