permission error while accessing firestore across project

[rmr-code]

I am in project A and would like to access firestore data in project B.

I have added in Project B IAM, project A's base account (project-a@appspot.gserviceaccount.com) as a service account and assigned it roles of cloud firestore editor.

The rule set for firestore in project B is:

service cloud.firestore {
  match /databases/{database}/documents {
    match /{document=**} {
      allow read, write: if false;
    }
  }
}

In my app, when I try to access project B firestore I receive a permission error. The code is:

let secondaryAppConfig = {
    projectId: project-b,
    databaseURL: let dbURL = 'https://project-b.firebaseio.com';
};
 // create the App
  let secondaryApp = admin.initializeApp(secondaryAppConfig, project-b);
 // get the database object
 secondarydb = admin.firestore(secondaryApp);

However, if I create a private key of the firestore of project B and share it with project A it works. Thus, the following works:

let serviceAccount = require(.. path to key json file ..)
let secondaryAppConfig = {
    credential: admin.credential.cert(serviceAccount),
    databaseURL: let dbURL = 'https://project-b.firebaseio.com';
};

 // create the App
  let secondaryApp = admin.initializeApp(secondaryAppConfig, project-b);
 // get the database object
 secondarydb = admin.firestore(secondaryApp);

What do I need to set in project B to get this working without sharing of the private key? Thanks

[google-oss-bot]

I found a few problems with this issue:

• I couldn't figure out how to label this issue, so I've labeled it for a human to triage. Hang tight.
• This issue does not seem to follow the issue template. Make sure you provide all the required information.

[hiranya911]

Stackoverflow is the right place to for usage questions such as this. Please follow up at https://stackoverflow.com/questions/55077644/google-function-accessing-firestore-database-of-another-project

[JeongJun-Lee]

Same here. Is there any solution?

[AshishisLiquid]

@JeongJun-Lee Maybe this could help you i tried my best to done this. I have done project deployment with single firestore. For Reference My project you can check