Manage GCP IAP Web Region Backend Service IAM Permissions

The gcp:iap/webRegionBackendServiceIamBinding:WebRegionBackendServiceIamBinding resource, part of the Pulumi GCP provider, manages IAM role bindings for Identity-Aware Proxy regional backend services. This resource is authoritative for a given role, meaning it controls the complete member list for that role while preserving other roles on the same backend service. This guide focuses on three capabilities: granting roles to multiple members, adding single members incrementally, and applying time-based access conditions.

IAM bindings reference existing IAP-protected regional backend services. The examples are intentionally small. Combine them with your own backend service infrastructure and identity management workflows.

Grant a role to multiple members at once

When managing IAP access, teams often need to grant the same role to multiple users or service accounts simultaneously.

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

const binding = new gcp.iap.WebRegionBackendServiceIamBinding("binding", {
    project: _default.project,
    region: _default.region,
    webRegionBackendService: _default.name,
    role: "roles/iap.httpsResourceAccessor",
    members: ["user:jane@example.com"],
});

import pulumi
import pulumi_gcp as gcp

binding = gcp.iap.WebRegionBackendServiceIamBinding("binding",
    project=default["project"],
    region=default["region"],
    web_region_backend_service=default["name"],
    role="roles/iap.httpsResourceAccessor",
    members=["user:jane@example.com"])

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := iap.NewWebRegionBackendServiceIamBinding(ctx, "binding", &iap.WebRegionBackendServiceIamBindingArgs{
			Project:                 pulumi.Any(_default.Project),
			Region:                  pulumi.Any(_default.Region),
			WebRegionBackendService: pulumi.Any(_default.Name),
			Role:                    pulumi.String("roles/iap.httpsResourceAccessor"),
			Members: pulumi.StringArray{
				pulumi.String("user:jane@example.com"),
			},
		})
		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 binding = new Gcp.Iap.WebRegionBackendServiceIamBinding("binding", new()
    {
        Project = @default.Project,
        Region = @default.Region,
        WebRegionBackendService = @default.Name,
        Role = "roles/iap.httpsResourceAccessor",
        Members = new[]
        {
            "user:jane@example.com",
        },
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamBinding;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamBindingArgs;
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 binding = new WebRegionBackendServiceIamBinding("binding", WebRegionBackendServiceIamBindingArgs.builder()
            .project(default_.project())
            .region(default_.region())
            .webRegionBackendService(default_.name())
            .role("roles/iap.httpsResourceAccessor")
            .members("user:jane@example.com")
            .build());

    }
}

resources:
  binding:
    type: gcp:iap:WebRegionBackendServiceIamBinding
    properties:
      project: ${default.project}
      region: ${default.region}
      webRegionBackendService: ${default.name}
      role: roles/iap.httpsResourceAccessor
      members:
        - user:jane@example.com

The binding resource treats the members list as a single unit for the specified role. When you update the members array, the resource replaces the entire member list for that role. The webRegionBackendService property identifies which backend service receives the access grant, while project and region specify its location.

Add time-based access with IAM Conditions

Access requirements sometimes include expiration dates or time windows for temporary grants.

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

const binding = new gcp.iap.WebRegionBackendServiceIamBinding("binding", {
    project: _default.project,
    region: _default.region,
    webRegionBackendService: _default.name,
    role: "roles/iap.httpsResourceAccessor",
    members: ["user:jane@example.com"],
    condition: {
        title: "expires_after_2019_12_31",
        description: "Expiring at midnight of 2019-12-31",
        expression: "request.time < timestamp(\"2020-01-01T00:00:00Z\")",
    },
});

import pulumi
import pulumi_gcp as gcp

binding = gcp.iap.WebRegionBackendServiceIamBinding("binding",
    project=default["project"],
    region=default["region"],
    web_region_backend_service=default["name"],
    role="roles/iap.httpsResourceAccessor",
    members=["user:jane@example.com"],
    condition={
        "title": "expires_after_2019_12_31",
        "description": "Expiring at midnight of 2019-12-31",
        "expression": "request.time < timestamp(\"2020-01-01T00:00:00Z\")",
    })

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := iap.NewWebRegionBackendServiceIamBinding(ctx, "binding", &iap.WebRegionBackendServiceIamBindingArgs{
			Project:                 pulumi.Any(_default.Project),
			Region:                  pulumi.Any(_default.Region),
			WebRegionBackendService: pulumi.Any(_default.Name),
			Role:                    pulumi.String("roles/iap.httpsResourceAccessor"),
			Members: pulumi.StringArray{
				pulumi.String("user:jane@example.com"),
			},
			Condition: &iap.WebRegionBackendServiceIamBindingConditionArgs{
				Title:       pulumi.String("expires_after_2019_12_31"),
				Description: pulumi.String("Expiring at midnight of 2019-12-31"),
				Expression:  pulumi.String("request.time < timestamp(\"2020-01-01T00:00:00Z\")"),
			},
		})
		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 binding = new Gcp.Iap.WebRegionBackendServiceIamBinding("binding", new()
    {
        Project = @default.Project,
        Region = @default.Region,
        WebRegionBackendService = @default.Name,
        Role = "roles/iap.httpsResourceAccessor",
        Members = new[]
        {
            "user:jane@example.com",
        },
        Condition = new Gcp.Iap.Inputs.WebRegionBackendServiceIamBindingConditionArgs
        {
            Title = "expires_after_2019_12_31",
            Description = "Expiring at midnight of 2019-12-31",
            Expression = "request.time < timestamp(\"2020-01-01T00:00:00Z\")",
        },
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamBinding;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamBindingArgs;
import com.pulumi.gcp.iap.inputs.WebRegionBackendServiceIamBindingConditionArgs;
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 binding = new WebRegionBackendServiceIamBinding("binding", WebRegionBackendServiceIamBindingArgs.builder()
            .project(default_.project())
            .region(default_.region())
            .webRegionBackendService(default_.name())
            .role("roles/iap.httpsResourceAccessor")
            .members("user:jane@example.com")
            .condition(WebRegionBackendServiceIamBindingConditionArgs.builder()
                .title("expires_after_2019_12_31")
                .description("Expiring at midnight of 2019-12-31")
                .expression("request.time < timestamp(\"2020-01-01T00:00:00Z\")")
                .build())
            .build());

    }
}

resources:
  binding:
    type: gcp:iap:WebRegionBackendServiceIamBinding
    properties:
      project: ${default.project}
      region: ${default.region}
      webRegionBackendService: ${default.name}
      role: roles/iap.httpsResourceAccessor
      members:
        - user:jane@example.com
      condition:
        title: expires_after_2019_12_31
        description: Expiring at midnight of 2019-12-31
        expression: request.time < timestamp("2020-01-01T00:00:00Z")

IAM Conditions attach temporal constraints to role grants through the condition block. The expression property uses Common Expression Language (CEL) to define when access is valid. Here, the condition checks whether the current request time falls before midnight on January 1, 2020. The title and description provide human-readable context for auditing.

Grant a role to a single member incrementally

When multiple teams manage access independently, member resources let each team add grants without coordinating on a shared list.

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

const member = new gcp.iap.WebRegionBackendServiceIamMember("member", {
    project: _default.project,
    region: _default.region,
    webRegionBackendService: _default.name,
    role: "roles/iap.httpsResourceAccessor",
    member: "user:jane@example.com",
});

import pulumi
import pulumi_gcp as gcp

member = gcp.iap.WebRegionBackendServiceIamMember("member",
    project=default["project"],
    region=default["region"],
    web_region_backend_service=default["name"],
    role="roles/iap.httpsResourceAccessor",
    member="user:jane@example.com")

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := iap.NewWebRegionBackendServiceIamMember(ctx, "member", &iap.WebRegionBackendServiceIamMemberArgs{
			Project:                 pulumi.Any(_default.Project),
			Region:                  pulumi.Any(_default.Region),
			WebRegionBackendService: pulumi.Any(_default.Name),
			Role:                    pulumi.String("roles/iap.httpsResourceAccessor"),
			Member:                  pulumi.String("user:jane@example.com"),
		})
		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 member = new Gcp.Iap.WebRegionBackendServiceIamMember("member", new()
    {
        Project = @default.Project,
        Region = @default.Region,
        WebRegionBackendService = @default.Name,
        Role = "roles/iap.httpsResourceAccessor",
        Member = "user:jane@example.com",
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamMember;
import com.pulumi.gcp.iap.WebRegionBackendServiceIamMemberArgs;
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 member = new WebRegionBackendServiceIamMember("member", WebRegionBackendServiceIamMemberArgs.builder()
            .project(default_.project())
            .region(default_.region())
            .webRegionBackendService(default_.name())
            .role("roles/iap.httpsResourceAccessor")
            .member("user:jane@example.com")
            .build());

    }
}

resources:
  member:
    type: gcp:iap:WebRegionBackendServiceIamMember
    properties:
      project: ${default.project}
      region: ${default.region}
      webRegionBackendService: ${default.name}
      role: roles/iap.httpsResourceAccessor
      member: user:jane@example.com

The member resource is non-authoritative, meaning it adds one identity to a role without affecting other members. Multiple teams can each create their own member resources for the same role and backend service. This approach works well when access grants come from different sources or approval workflows.

Beyond these examples

These snippets focus on specific IAM binding features: role binding for multiple members, incremental member grants, and time-based IAM Conditions. They’re intentionally minimal rather than complete access control configurations.

The examples reference pre-existing infrastructure such as IAP-protected regional backend services and GCP project and region configuration. They focus on configuring access grants rather than provisioning the underlying backend services.

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

Full policy replacement (WebRegionBackendServiceIamPolicy)
Policy data retrieval and auditing
Custom role definitions and formatting
Federated identity and workload identity pool configuration

These omissions are intentional: the goal is to illustrate how each IAM binding feature is wired, not provide drop-in access control modules. See the WebRegionBackendServiceIamBinding resource reference for all available configuration options.

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Frequently Asked Questions

Resource Conflicts & Compatibility

Can I use IamPolicy together with IamBinding or IamMember?

No, gcp.iap.WebRegionBackendServiceIamPolicy cannot be used with gcp.iap.WebRegionBackendServiceIamBinding or gcp.iap.WebRegionBackendServiceIamMember because they will conflict over the policy configuration. Choose one approach: IamPolicy for full policy control, or IamBinding/IamMember for per-role/per-member management.

Can I use IamBinding and IamMember together?

Yes, but only if they don’t grant privileges to the same role. Using both resources for the same role will cause conflicts.

IAM Configuration & Member Identities

What member identity formats are supported?

The members property supports multiple formats:

allUsers or allAuthenticatedUsers for broad access
user:{email}, serviceAccount:{email}, group:{email} for specific identities
domain:{domain} for G Suite domains
projectOwner:{projectid}, projectEditor:{projectid}, projectViewer:{projectid} for project-level roles
Federated identities like principal://iam.googleapis.com/locations/global/workforcePools/...

How do I specify a custom IAM role?

Custom roles must use the format [projects|organizations]/{parent-name}/roles/{role-name}. For example: projects/my-project/roles/customRole or organizations/my-org/roles/customRole.

IAM Conditions & Advanced Features

How do I set up time-based access with IAM Conditions?

Use the condition property with title, description, and expression fields. For example, to expire access at midnight on 2020-01-01: expression: "request.time < timestamp(\"2020-01-01T00:00:00Z\")". Note that IAM Conditions have known limitations that may affect certain use cases.

Resource Management

What properties can't be changed after creation?

The role, condition, project, region, and webRegionBackendService properties are immutable and require resource replacement if changed.

What import formats are supported for this resource?

You can import using multiple formats: full path (projects/{project}/iap_web/compute-{region}/services/{name}), or shortened forms ({project}/{region}/{name}, {region}/{name}, or just {name}). Any variables not specified in the import command are taken from the provider configuration.

Using a different cloud?

Explore security guides for other cloud providers:

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