How do I add Google Application Credentials/Secret to Vercel Deployment?

Question

I am using Vercel Deployments with a NextJS app. Deployments are automatically run when I push to master, but I don't want to store keys in GitHub. My serverless functions are reliant on my database. When run locally, I can simply use Google's Default Authentication Credentials, but this is not possible when deployed to Vercel. As such, I created a Service Account to enable the server to have access.

How do I load the service account credentials without pushing they key itself to GitHub?

• I tried adding the key as described in this issue, but that didn't work.

• AFAIK setting an environment variable in Vercel is not helpful because Google environment variables require a path/JSON file (vs. simply text).

Answer 1

Rather than using a path to a JSON file, you can create an object and include environment variables as the values for each object key. For example:

admin.initializeApp({
  credential: admin.credential.cert({
    client_email: process.env.FIREBASE_CLIENT_EMAIL,
    private_key: process.env.FIREBASE_PRIVATE_KEY,
    project_id: 'my-project'
  }),
  databaseURL: 'https://my-project.firebaseio.com'
});

Then, you can add the environment variables inside your project settings in Vercel.