Configure GCP Firebase App Hosting Default Domains

The gcp:firebase/appHostingDefaultDomain:AppHostingDefaultDomain resource, part of the Pulumi GCP provider, associates a default domain with a Firebase App Hosting backend, providing an automatically-generated URL for serving traffic. This guide focuses on two capabilities: default domain creation and traffic control via the disabled flag.

Default domains depend on an existing Firebase App Hosting backend, which requires a service account and Firebase web app. The examples are intentionally small. Combine them with your own backend configuration and project settings.

Associate a default domain with a backend

Firebase App Hosting backends need a domain to serve traffic. The default domain provides an automatically-generated URL without requiring custom DNS configuration.

import * as pulumi from "@pulumi/pulumi";
import * as gcp from "@pulumi/gcp";

const serviceAccount = new gcp.serviceaccount.Account("service_account", {
    project: "my-project-name",
    accountId: "service-account",
    displayName: "Firebase App Hosting compute service account",
    createIgnoreAlreadyExists: true,
});
const exampleAppHostingBackend = new gcp.firebase.AppHostingBackend("example", {
    project: "my-project-name",
    location: "us-central1",
    backendId: "dd-mini",
    appId: "1:0000000000:web:674cde32020e16fbce9dbd",
    servingLocality: "GLOBAL_ACCESS",
    serviceAccount: serviceAccount.email,
});
const example = new gcp.firebase.AppHostingDefaultDomain("example", {
    project: exampleAppHostingBackend.project,
    location: exampleAppHostingBackend.location,
    backend: exampleAppHostingBackend.backendId,
    domainId: exampleAppHostingBackend.uri,
});

import pulumi
import pulumi_gcp as gcp

service_account = gcp.serviceaccount.Account("service_account",
    project="my-project-name",
    account_id="service-account",
    display_name="Firebase App Hosting compute service account",
    create_ignore_already_exists=True)
example_app_hosting_backend = gcp.firebase.AppHostingBackend("example",
    project="my-project-name",
    location="us-central1",
    backend_id="dd-mini",
    app_id="1:0000000000:web:674cde32020e16fbce9dbd",
    serving_locality="GLOBAL_ACCESS",
    service_account=service_account.email)
example = gcp.firebase.AppHostingDefaultDomain("example",
    project=example_app_hosting_backend.project,
    location=example_app_hosting_backend.location,
    backend=example_app_hosting_backend.backend_id,
    domain_id=example_app_hosting_backend.uri)

package main

import (
	"github.com/pulumi/pulumi-gcp/sdk/v9/go/gcp/firebase"
	"github.com/pulumi/pulumi-gcp/sdk/v9/go/gcp/serviceaccount"
	"github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		serviceAccount, err := serviceaccount.NewAccount(ctx, "service_account", &serviceaccount.AccountArgs{
			Project:                   pulumi.String("my-project-name"),
			AccountId:                 pulumi.String("service-account"),
			DisplayName:               pulumi.String("Firebase App Hosting compute service account"),
			CreateIgnoreAlreadyExists: pulumi.Bool(true),
		})
		if err != nil {
			return err
		}
		exampleAppHostingBackend, err := firebase.NewAppHostingBackend(ctx, "example", &firebase.AppHostingBackendArgs{
			Project:         pulumi.String("my-project-name"),
			Location:        pulumi.String("us-central1"),
			BackendId:       pulumi.String("dd-mini"),
			AppId:           pulumi.String("1:0000000000:web:674cde32020e16fbce9dbd"),
			ServingLocality: pulumi.String("GLOBAL_ACCESS"),
			ServiceAccount:  serviceAccount.Email,
		})
		if err != nil {
			return err
		}
		_, err = firebase.NewAppHostingDefaultDomain(ctx, "example", &firebase.AppHostingDefaultDomainArgs{
			Project:  exampleAppHostingBackend.Project,
			Location: exampleAppHostingBackend.Location,
			Backend:  exampleAppHostingBackend.BackendId,
			DomainId: exampleAppHostingBackend.Uri,
		})
		if err != nil {
			return err
		}
		return nil
	})
}

using System.Collections.Generic;
using System.Linq;
using Pulumi;
using Gcp = Pulumi.Gcp;

return await Deployment.RunAsync(() => 
{
    var serviceAccount = new Gcp.ServiceAccount.Account("service_account", new()
    {
        Project = "my-project-name",
        AccountId = "service-account",
        DisplayName = "Firebase App Hosting compute service account",
        CreateIgnoreAlreadyExists = true,
    });

    var exampleAppHostingBackend = new Gcp.Firebase.AppHostingBackend("example", new()
    {
        Project = "my-project-name",
        Location = "us-central1",
        BackendId = "dd-mini",
        AppId = "1:0000000000:web:674cde32020e16fbce9dbd",
        ServingLocality = "GLOBAL_ACCESS",
        ServiceAccount = serviceAccount.Email,
    });

    var example = new Gcp.Firebase.AppHostingDefaultDomain("example", new()
    {
        Project = exampleAppHostingBackend.Project,
        Location = exampleAppHostingBackend.Location,
        Backend = exampleAppHostingBackend.BackendId,
        DomainId = exampleAppHostingBackend.Uri,
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.serviceaccount.Account;
import com.pulumi.gcp.serviceaccount.AccountArgs;
import com.pulumi.gcp.firebase.AppHostingBackend;
import com.pulumi.gcp.firebase.AppHostingBackendArgs;
import com.pulumi.gcp.firebase.AppHostingDefaultDomain;
import com.pulumi.gcp.firebase.AppHostingDefaultDomainArgs;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Paths;

public class App {
    public static void main(String[] args) {
        Pulumi.run(App::stack);
    }

    public static void stack(Context ctx) {
        var serviceAccount = new Account("serviceAccount", AccountArgs.builder()
            .project("my-project-name")
            .accountId("service-account")
            .displayName("Firebase App Hosting compute service account")
            .createIgnoreAlreadyExists(true)
            .build());

        var exampleAppHostingBackend = new AppHostingBackend("exampleAppHostingBackend", AppHostingBackendArgs.builder()
            .project("my-project-name")
            .location("us-central1")
            .backendId("dd-mini")
            .appId("1:0000000000:web:674cde32020e16fbce9dbd")
            .servingLocality("GLOBAL_ACCESS")
            .serviceAccount(serviceAccount.email())
            .build());

        var example = new AppHostingDefaultDomain("example", AppHostingDefaultDomainArgs.builder()
            .project(exampleAppHostingBackend.project())
            .location(exampleAppHostingBackend.location())
            .backend(exampleAppHostingBackend.backendId())
            .domainId(exampleAppHostingBackend.uri())
            .build());

    }
}

resources:
  example:
    type: gcp:firebase:AppHostingDefaultDomain
    properties:
      project: ${exampleAppHostingBackend.project}
      location: ${exampleAppHostingBackend.location}
      backend: ${exampleAppHostingBackend.backendId}
      domainId: ${exampleAppHostingBackend.uri}
  exampleAppHostingBackend:
    type: gcp:firebase:AppHostingBackend
    name: example
    properties:
      project: my-project-name
      location: us-central1
      backendId: dd-mini
      appId: 1:0000000000:web:674cde32020e16fbce9dbd
      servingLocality: GLOBAL_ACCESS
      serviceAccount: ${serviceAccount.email}
  serviceAccount:
    type: gcp:serviceaccount:Account
    name: service_account
    properties:
      project: my-project-name
      accountId: service-account
      displayName: Firebase App Hosting compute service account
      createIgnoreAlreadyExists: true

The backend property links the domain to your App Hosting backend. The domainId follows the format {{backend}}--{{project_id}}.{{location}}.hosted.app, which Firebase generates automatically. The domain becomes active immediately, routing requests to your backend.

Disable traffic to a default domain

When migrating to a custom domain or temporarily suspending a backend, you can disable the default domain without deleting it.

import * as pulumi from "@pulumi/pulumi";
import * as gcp from "@pulumi/gcp";

const serviceAccount = new gcp.serviceaccount.Account("service_account", {
    project: "my-project-name",
    accountId: "service-account",
    displayName: "Firebase App Hosting compute service account",
    createIgnoreAlreadyExists: true,
});
const exampleAppHostingBackend = new gcp.firebase.AppHostingBackend("example", {
    project: "my-project-name",
    location: "us-central1",
    backendId: "dd-disabled",
    appId: "1:0000000000:web:674cde32020e16fbce9dbd",
    servingLocality: "GLOBAL_ACCESS",
    serviceAccount: serviceAccount.email,
});
const example = new gcp.firebase.AppHostingDefaultDomain("example", {
    project: exampleAppHostingBackend.project,
    location: exampleAppHostingBackend.location,
    backend: exampleAppHostingBackend.backendId,
    domainId: exampleAppHostingBackend.uri,
    disabled: true,
});

import pulumi
import pulumi_gcp as gcp

service_account = gcp.serviceaccount.Account("service_account",
    project="my-project-name",
    account_id="service-account",
    display_name="Firebase App Hosting compute service account",
    create_ignore_already_exists=True)
example_app_hosting_backend = gcp.firebase.AppHostingBackend("example",
    project="my-project-name",
    location="us-central1",
    backend_id="dd-disabled",
    app_id="1:0000000000:web:674cde32020e16fbce9dbd",
    serving_locality="GLOBAL_ACCESS",
    service_account=service_account.email)
example = gcp.firebase.AppHostingDefaultDomain("example",
    project=example_app_hosting_backend.project,
    location=example_app_hosting_backend.location,
    backend=example_app_hosting_backend.backend_id,
    domain_id=example_app_hosting_backend.uri,
    disabled=True)

package main

import (
	"github.com/pulumi/pulumi-gcp/sdk/v9/go/gcp/firebase"
	"github.com/pulumi/pulumi-gcp/sdk/v9/go/gcp/serviceaccount"
	"github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		serviceAccount, err := serviceaccount.NewAccount(ctx, "service_account", &serviceaccount.AccountArgs{
			Project:                   pulumi.String("my-project-name"),
			AccountId:                 pulumi.String("service-account"),
			DisplayName:               pulumi.String("Firebase App Hosting compute service account"),
			CreateIgnoreAlreadyExists: pulumi.Bool(true),
		})
		if err != nil {
			return err
		}
		exampleAppHostingBackend, err := firebase.NewAppHostingBackend(ctx, "example", &firebase.AppHostingBackendArgs{
			Project:         pulumi.String("my-project-name"),
			Location:        pulumi.String("us-central1"),
			BackendId:       pulumi.String("dd-disabled"),
			AppId:           pulumi.String("1:0000000000:web:674cde32020e16fbce9dbd"),
			ServingLocality: pulumi.String("GLOBAL_ACCESS"),
			ServiceAccount:  serviceAccount.Email,
		})
		if err != nil {
			return err
		}
		_, err = firebase.NewAppHostingDefaultDomain(ctx, "example", &firebase.AppHostingDefaultDomainArgs{
			Project:  exampleAppHostingBackend.Project,
			Location: exampleAppHostingBackend.Location,
			Backend:  exampleAppHostingBackend.BackendId,
			DomainId: exampleAppHostingBackend.Uri,
			Disabled: pulumi.Bool(true),
		})
		if err != nil {
			return err
		}
		return nil
	})
}

using System.Collections.Generic;
using System.Linq;
using Pulumi;
using Gcp = Pulumi.Gcp;

return await Deployment.RunAsync(() => 
{
    var serviceAccount = new Gcp.ServiceAccount.Account("service_account", new()
    {
        Project = "my-project-name",
        AccountId = "service-account",
        DisplayName = "Firebase App Hosting compute service account",
        CreateIgnoreAlreadyExists = true,
    });

    var exampleAppHostingBackend = new Gcp.Firebase.AppHostingBackend("example", new()
    {
        Project = "my-project-name",
        Location = "us-central1",
        BackendId = "dd-disabled",
        AppId = "1:0000000000:web:674cde32020e16fbce9dbd",
        ServingLocality = "GLOBAL_ACCESS",
        ServiceAccount = serviceAccount.Email,
    });

    var example = new Gcp.Firebase.AppHostingDefaultDomain("example", new()
    {
        Project = exampleAppHostingBackend.Project,
        Location = exampleAppHostingBackend.Location,
        Backend = exampleAppHostingBackend.BackendId,
        DomainId = exampleAppHostingBackend.Uri,
        Disabled = true,
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.serviceaccount.Account;
import com.pulumi.gcp.serviceaccount.AccountArgs;
import com.pulumi.gcp.firebase.AppHostingBackend;
import com.pulumi.gcp.firebase.AppHostingBackendArgs;
import com.pulumi.gcp.firebase.AppHostingDefaultDomain;
import com.pulumi.gcp.firebase.AppHostingDefaultDomainArgs;
import java.util.List;
import java.util.ArrayList;
import java.util.Map;
import java.io.File;
import java.nio.file.Files;
import java.nio.file.Paths;

public class App {
    public static void main(String[] args) {
        Pulumi.run(App::stack);
    }

    public static void stack(Context ctx) {
        var serviceAccount = new Account("serviceAccount", AccountArgs.builder()
            .project("my-project-name")
            .accountId("service-account")
            .displayName("Firebase App Hosting compute service account")
            .createIgnoreAlreadyExists(true)
            .build());

        var exampleAppHostingBackend = new AppHostingBackend("exampleAppHostingBackend", AppHostingBackendArgs.builder()
            .project("my-project-name")
            .location("us-central1")
            .backendId("dd-disabled")
            .appId("1:0000000000:web:674cde32020e16fbce9dbd")
            .servingLocality("GLOBAL_ACCESS")
            .serviceAccount(serviceAccount.email())
            .build());

        var example = new AppHostingDefaultDomain("example", AppHostingDefaultDomainArgs.builder()
            .project(exampleAppHostingBackend.project())
            .location(exampleAppHostingBackend.location())
            .backend(exampleAppHostingBackend.backendId())
            .domainId(exampleAppHostingBackend.uri())
            .disabled(true)
            .build());

    }
}

resources:
  example:
    type: gcp:firebase:AppHostingDefaultDomain
    properties:
      project: ${exampleAppHostingBackend.project}
      location: ${exampleAppHostingBackend.location}
      backend: ${exampleAppHostingBackend.backendId}
      domainId: ${exampleAppHostingBackend.uri}
      disabled: true
  exampleAppHostingBackend:
    type: gcp:firebase:AppHostingBackend
    name: example
    properties:
      project: my-project-name
      location: us-central1
      backendId: dd-disabled
      appId: 1:0000000000:web:674cde32020e16fbce9dbd
      servingLocality: GLOBAL_ACCESS
      serviceAccount: ${serviceAccount.email}
  serviceAccount:
    type: gcp:serviceaccount:Account
    name: service_account
    properties:
      project: my-project-name
      accountId: service-account
      displayName: Firebase App Hosting compute service account
      createIgnoreAlreadyExists: true

Setting disabled to true stops the domain from serving traffic while preserving its configuration. This is useful during maintenance windows or when transitioning to custom domains. Set it back to false to resume serving traffic.

Beyond these examples

These snippets focus on specific default domain features: default domain association and traffic control via disabled flag. They’re intentionally minimal rather than full hosting configurations.

The examples require pre-existing infrastructure such as Firebase App Hosting backend, service account for backend compute, and Firebase web app (appId). They focus on domain configuration rather than provisioning the backend infrastructure.

To keep things focused, common domain patterns are omitted, including:

Custom domain configuration (separate resource)
SSL certificate management
Domain verification workflows

These omissions are intentional: the goal is to illustrate how default domain features are wired, not provide drop-in hosting modules. See the Firebase App Hosting Default Domain resource reference for all available configuration options.

Let's configure GCP Firebase App Hosting Default Domains

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Frequently Asked Questions

Configuration & Setup

Do I need to create a backend before creating a default domain?

Yes, the domain requires an existing AppHostingBackend resource. All examples show the domain referencing the backend’s project, location, backendId, and uri properties.

What format should I use for the domainId?

For default domains, use the format {{backend}}--{{project_id}}.{{location}}.hosted.app. In practice, you can reference the backend’s uri property as shown in the examples.

Domain Management

What properties can't I change after creating the domain?

The backend, domainId, location, and project properties are immutable and cannot be modified after creation.

Is the domain enabled by default?

Yes, domains are enabled by default. The disabled property defaults to false.

How do I disable a domain?

Set the disabled property to true when creating or updating the domain.

Using a different cloud?

Explore networking guides for other cloud providers:

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