Failed host lookup: while using dart frog.

[guccisekspir]

Hello,

I was trying to implement dart firebase admin library to my dart:frog project. It is successfully initializing but when I try to do anything related firestore I get
Failed host lookup: 'metadata.google.internal'

I dont have any logic I am just calling on main.

Future<FirebaseAdminApp> init(InternetAddress ip, int port) async {
  final admin = FirebaseAdminApp.initializeApp(
    'gizemlikutucom',
    // This will obtain authentication informations from the environment
    Credential.fromApplicationDefaultCredentials(),
  );

  return admin;
}

Future<HttpServer> run(Handler handler, InternetAddress ip, int port) async {
  FirebaseAdminApp admin = await init(ip, port);

  try {
    final firestore = Firestore(admin);
    DocumentSnapshot a = await firestore.collection("a").doc("b").get();

    print(a.data());
  } catch (e) {
    print(e);
  }

  return serve(handler, ip, port);
}

here the versions

environment:
  sdk: ">=3.0.0 <4.0.0"

dependencies:
  dart_firebase_admin: ^0.0.2
  dart_frog: ^1.0.0
  shelf_cors_headers: ^0.1.5

[Ehesp]

Are you getting this error in local development?

[guccisekspir]

Yes!

[Ehesp]

Thanks - does this error throw when calling firestore, or when initializing the app?

[guccisekspir]

initializing working well, it is about calling firestore. Get set etc. all functions throw this error.

[rrousselGit]

Do you maybe have some stracktrace and a more complete example? Ideally something we can run

Firestore is working fine for me, and there's no reference to metadata.google.internal in the source, so I'm not immediately sure where that error is from.

[guccisekspir]

Okey I will try but is firestore working fine for you on dart frog project @rrousselGit ?

[rrousselGit]

Acutally I think I know what this endpoint is.
But I still need a stacktrace from you.

[guccisekspir]

Here the stack trace

#0      IOClient.send (package:http/src/io_client.dart:94:7)
<asynchronous suspension>
#1      BaseClient._sendUnstreamed (package:http/src/base_client.dart:93:32)
<asynchronous suspension>
#2      MetadataServerAuthorizationFlow._getScopes (package:googleapis_auth/src/oauth2_flows/metadata_server.dart:89:22)
<asynchronous suspension>
#3      Future.wait.<anonymous closure> (dart:async/future.dart:525:21)
<asynchronous suspension>
#4      MetadataServerAuthorizationFlow.run (package:googleapis_auth/src/oauth2_flows/metadata_server.dart:63:21)
<asynchronous suspension>
#5      clientFromFlow (package:googleapis_auth/src/oauth2_flows/base_flow.dart:27:25)
<asynchronous suspension>
#6      clientViaMetadataServer (package:googleapis_auth/src/metadata_server_client.dart:43:5)
<asynchronous suspension>
#7      clientViaApplicationDefaultCredentials (package:googleapis_auth/auth_io.dart:95:10)
<asynchronous suspension>
#8      _FirestoreHttpClient._getClient (package:dart_firebase_admin/src/google_cloud_firestore/firestore.dart:176:24)
<asynchronous suspension>
#9      _FirestoreHttpClient.v1.<anonymous closure> (package:dart_firebase_admin/src/google_cloud_firestore/firestore.dart:188:11)
<asynchronous suspension>
#10     DocumentReader._fetchDocuments (package:dart_firebase_admin/src/google_cloud_firestore/document_reader.dart:50:23)
<asynchronous suspension>
#11     DocumentReader.get (package:dart_firebase_admin/src/google_cloud_firestore/document_reader.dart:21:5)
<asynchronous suspension>
#12     DocumentReference.get (package:dart_firebase_admin/src/google_cloud_firestore/reference.dart:223:20)
<asynchronous suspension>
#13     run (file:///Users/cagri/Documents/GitHub/gizemli_kutu_back/main.dart:29:26)
<asynchronous suspension>
#14     withHotreload.<anonymous closure> (package:shelf_hotreload/src/with_hotreload.dart:81:21)
<asynchronous suspension>
#15     withHotreload (package:shelf_hotreload/src/with_hotreload.dart:102:3)
<asynchronous suspension>

[rrousselGit]

I am not fully sure why yet, but that issue appears to be caused by logging in with the environment.
I'll see if I can update the source to get a better error message, and try a few things to see if I can reproduce it locally.

But for now, you could try logging in with a service-account.json file. That likely would work

[rrousselGit]

Alternatively, are you trying to use the emulator but maybe didn't start it?

[rrousselGit]

The weird thing is that it's googleapis_auth who's failing, not the Admin SDK itself. Maybe we should chat with them to see what could possibly cause this.

[rrousselGit]

I think I know:

You don't seem to be logged in. Therefore googleapis_auth fallbacks to reaching out to the google-cloud-only API for logging in – which fails since you're working locally.

You should have one of the following setup:

• Platform.environment['GOOGLE_APPLICATION_CREDENTIALS']
• on windows, %appdata%/gcloud/application_default_credentials.json
• otherwise $HOME/.config/gcloud/application_default_credentials.json (with HOME env set!)

If none of these are true, you'll end-up with this error.

The error message is cryptic, but likely expected.

[rrousselGit]

Closing as this was answered. I raised a PR to improve the error message. It's only a matter of time before the message is more intuitive :)

[mafreud]

Same issue here. I hope a better error message comes to this package.

Btw, authenticating with service account json works fine.