Upstream Firebase User Auth Policy

This policy adds a Firebase Admin token to the outgoing Authentication header allowing requests to Firebase using Service Account admin permissions. This can be useful for calling Firebase services such as Firestore through a Zuplo endpoint that is secured with other means of Authentication such as API keys. Additionally, this policy can be useful for service content to all API users (for example serving a specific Firestore document containing configuration data)

We recommend reading the serviceAccountJson from environment variables (so it is not checked in to source control) using the $env(ENV_VAR) syntax.

Configuration

{
  "name": "my-upstream-firebase-user-auth-inbound-policy",
  "policyType": "upstream-firebase-user-auth-inbound",
  "handler": {
    "export": "UpstreamFirebaseUserAuthInboundPolicy",
    "module": "$import(@zuplo/runtime)",
    "options": {
      "serviceAccountJson": "$env(SERVICE_ACCOUNT_JSON)",
      "webApiKey": "$env(WEB_API_KEY)",
      "userId": "1234",
      "developerClaims": {
        "premium": true
      }
    }
  }
}

name the name of your policy instance. This is used as a reference in your routes.
policyType the identifier of the policy. This is used by the Zuplo UI. Value should be upstream-firebase-user-auth-inbound.
handler/export The name of the exported type. Value should be UpstreamFirebaseUserAuthInboundPolicy.
handler/module the module containing the policy. Value should be $import(@zuplo/runtime).
handler/options The options for this policy:
- serviceAccountJson
  The Google Service Account key in JSON format. Note you can load this from environment variables using the $env(ENV_VAR) syntax.
- userId
  The userId to use as the custom token's subject.
- userIdPropertyPath
  The property on the incoming request.user object to retrieve the value of the userId
- developerClaims
  Optional additional claims to include in the custom token's payload.
- webApiKey
  The Firebase Web API Key (found in project settings)
- tokenRetries
  The number of times to retry fetching the token in the event of a failure. Defaults to 3.
- expirationOffsetSeconds
  The number of seconds less than the token expiration to cache the token. Defaults to 300 seconds.

Configuration​

Configuration