Connect to firestore emulator with admin SDK requires supplying the project-id

Edit: Summary of the discussion below:

1. The firebase admin SDK must init with some project-id, but it doesn’t have to be a real one.
2. Meanwhile, if you also want to visualize the db using the emulator UI, or if you’re using the function emulator at the same time, then the emulator must start with the same project-id as the admin SDK. This can be achieved with firebase --project=some_project_id emulators:start. Without the flag, the emulator will use the project id in your .firebaserc, and create a different instance of db running parallel with the admin SDK’s instance.

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Original issue:

I found that when I have a firestore running on local emulator, and I want to directly access it with a script using the admin SDK, I need to supply the project-id to the admin SDK, which I believe is not the intended behavior.

I use the nodejs firebase-admin package, not sure if the bug is theirs.

[REQUIRED] Environment info

firebase-tools: 8.10.0 npm firebase-admin package 9.1.1

Platform: Windows

[REQUIRED] Test case

see below

[REQUIRED] Steps to reproduce

1. have the firestore emulator running
2. create a test.js locally:

const admin = require('firebase-admin'); 
admin.initializeApp();
admin.firestore().collection('foo').add({ a: 1 });

1. run it: $ FIRESTORE_EMULATOR_HOST="localhost:8080" node test.js

[REQUIRED] Expected behavior

should see a document created in the emulator firestore UI

[REQUIRED] Actual behavior

Error: Unable to detect a Project Id in the current environment.

To fix this, I need to supply the project id to the admin SDK:

admin.initializeApp({ projectId: 'my-project-id' }); // now works

But I believe it’s not the intended behavior.

[thMthMnky]

With the following environment variables:

GCLOUD_PROJECT="test-my-project" 

FIREBASE_AUTH_EMULATOR_HOST="localhost:9099",

The following initialization seemed to allow the admin SDK to use the firestore emulator but it only allowed partial use of the auth emulator (calls to admin.auth().listUsers() returned an empty array despite there being at least one emulated user):

import * as admin from 'firebase-admin'

admin.initializeApp({ projectId: process.env.GCLOUD_PROJECT});

const Firestore = admin.firestore();

Firestore.settings({
      host: "localhost:8080",
      ssl: false
});

Currently using: firebase-tools: v9.4.0 npm firebase-admin package v9.5.0

[samtstern]

@RicardoAratani we are working on a plan to make it much more obvious when you have a project ID mismatch and also make it easier to set things up!