Is there a way to enable Firebase Auth via Email through an API/CLI? - firebase

Question

We are transitioning to using Terraform to create our architecture on Google Compute, and part of it utilises Firebase for the front-end. So far, I have managed to get this all working fine, but have hit a snag on Firebase Auth. Essentially, I want to allow 'Email/Password' authentication on a Firbase project programmatically.
The above shows where you find the setting in the UI console, but I want to be able to do that via an API/CLI, and also set the 'Authorised Domain'.

Answer 1

Yes, as of November 2022, this is now possible, either using Terraform, or the gcloud CLI and a bit of scripting. Both methods make use of the REST Identity Toolkit API.
If using Terraform: Your config file needs to specify a google_identity_platform_project_default_config resource: the documentation for it is available here. By way of example – assuming you've already declared a google_project resource called my_project, you could add the google_identity_platform_project_default_config resource as follows:
resource "google_identity_platform_project_default_config" "myconfig" {
project = google_project.myproject.project_id
sign_in {
allow_duplicate_emails = false
anonymous {
enabled = false
}
email {
enabled = true
password_required = false
}
}
}
This would enable email+password authentication, disallow anonymous access, and disallow duplicate email addresses.
If using the gcloud CLI: This would be a good deal fiddlier. I haven't tested it out completely, but it is presumably equivalent to what Terraform is doing behind the scenes. You need to obtain a service account access token, then use cURL (or a similar tool/API) to amend the Identity Toolkit configuration using the PATCH method (documentation here), supplying the token in the "Authorization" header.
gcloud lets you get an access token using the command gcloud auth print-access-token, but according to this 2021 blog post1 by #DazWilkin, the token obtained using your regular human credentials can't perform the necessary PATCH operation; you need to use a token backed by a service account that has the correct permissions.
The blog post gives further details, but roughly, the steps are:
Create a service account and give it the correct permissions. (Not necessary if you already have an appropriate service account; such an account can be created either using the Firebase console or Terraform's google_service_account resource.)
Create a JSON service account key file. (Not necessary if you already have a key created, plus a JSON file for it. These JSON files contain an object with the keys "project_id", "private_key_id", and "private_key", and are exactly the same sort of file as gets generated from the Firebase console if you go to "Project Overview" / "Project Settings" / "Service Accounts" / "Generate new private key". They can also be created programmatically using Terraform's google_service_account_key resource.)
Allow gcloud to perform operations using the service account's permissions, by running gcloud's "auth activate-service-account" subcommand: something like
$ gcloud auth activate-service-account --key-file=/path/to/key-file.json EMAIL_ADDRESS_OF_SERVICE_ACCOUNT
Obtain an access token for the service account by running gcloud auth print-access-token EMAIL_ADDRESS_OF_SERVICE_ACCOUNT.
Supply that token in the header of an HTTP PATCH request using cURL.
For more details, see the blog post; it's concerned with amending the "authorized domains" list for a Firebase project, but enabling email/password authentication would be very similar.
1 Also mentioned in this stackoverflow answer.