I encountered a similar issue and, like exampleuser, I was able to resolve it by adjusting permissions.

When I created a function, I noticed that the default service account was set to

<project-name>@appspot.gserviceaccount.com

You can confirm this by accessing the

Environment variables, networking, timeouts, and more

From there, make sure to verify or change the account to the 'App Engine default service account':

Next, I checked the IAM to review the permissions assigned to this service account.

However, the IAM did not have the service account listed in its records.

To address this, I added the service account by going to >> Add >> New members. By entering the project ID, the service account should appear in the drop-down for selection.

Subsequently, I granted the following permissions:

• Project >> Editor (It may already have this)
• Datastore >> Cloud Datastore Owner
• Storage >> Storage Admin

I hope this solution proves beneficial to you as well.

To solve the issue, I took the necessary steps to set up the serviceAccount. Here's a snippet of the code that worked for me:

const admin = require("firebase-admin");

const serviceAccount = require("path/to/serviceAccountKey.json");

admin.initializeApp({
  credential: admin.credential.cert(serviceAccount),
  databaseURL: "https://your-database-url.firebaseio.com"
});

If you're not sure how to generate the serviceAccountKey, you can do so by accessing: Firebase dashboard -> Project Settings -> Service Accounts tab

I hope this solution proves helpful!

Dealing with Cloud Functions also presented a challenge for me. Simply deleting or redeploying the function did not resolve my issue. Upon further investigation, I discovered that the IAM roles for the default service account were not properly configured when my project was set up. To rectify this, I had to manually assign an Editor role in the IAM Admin panel for

<project-name>@appspot.gserviceaccount.com

I encountered a similar error and after searching extensively, I couldn't find a solution. So, I decided to share my experience here in case it might help someone else...

We operate with two separate firebase projects; one for development (DEV) and the other for production (PROD). The PERMISSION_DENIED issue can also arise if you mistakenly specify the wrong projectId in the following line of code:

admin.initializeApp({projectId: 'your_project_id'});

Here's a solution that successfully resolved my issue:

• My problem arose from switching between different Firebase projects in order to test a Cloud Function and observe the results in production within Firestore. Despite having the Cloud Function set up to create data in production Firestore for one project (e.g., "project-dev"), I consistently encountered a permission denied error when attempting to create new documents via the cloud function using the downloaded serviceAccount credentials for another project ("project-sandbox").

let serviceAccount = require('../credentials-sb.json');
admin.initializeApp({
    credential: admin.credential.cert(serviceAccount),
    databaseURL: "https://<project>-sandbox.firebaseio.com"
});

• I realized that I had not yet utilized the firebase use command for the new project, nor had I added it to .firebaserc file. Essentially, I was operating under a different project setting than what the credentials file required. After running firebase use project-sandbox, followed by npm run shell to execute my function from the emulator, everything functioned seamlessly. The emulator served its purpose correctly for both "project-sandbox" and "project-dev".

It is likely that this was due to defining a project-id environment variable automatically detected during the execution of admin.initializeApp(), or alternatively, could have been manually set as demonstrated below:

let serviceAccount = require('../credentials-sb.json');
admin.initializeApp({
    project-id: '<project>-sandbox'
    credential: admin.credential.cert(serviceAccount),
    databaseURL: "https://inkling-sandbox.firebaseio.com"
});

I trust that these insights are beneficial! Feel free to share your feedback on the outcome.

A quick and effective fix that solved the issue for me was executing these commands:

firebase login //login using browser with project account
firebase init firestore //When prompted, choose the firebase project

I made sure to run this in the same directory where I set up the project initially.

Important Note: Always select No when it asks about overwriting any files.

Additional Tip: This approach resolved my local functions not functioning properly after transferring the project between machines. Reinitializing the project proved to be the solution when nothing else worked.

After encountering issues with my service account, I decided to recreate it from scratch and then redeploy it.

By creating a new service account, I was able to resolve this issue efficiently.

1. To resolve the issue, I created a new service account in IAM.
2. Next, I assigned the roles 'Cloud Datastore User' and 'Firebase Rules Viewer' to the new service account in IAM.
3. Finally, I edited the function details in Cloud Functions and configured it to use the new service account.