Manage GCP Subnetwork IAM Permissions

The gcp:compute/subnetworkIAMMember:SubnetworkIAMMember resource, part of the Pulumi GCP provider, grants IAM permissions on VPC subnetworks by adding individual members to roles non-authoritatively. This guide focuses on three capabilities: single-member role grants, time-limited access with IAM Conditions, and multi-member role management.

Subnetwork IAM resources reference existing subnetworks by name, project, and region. The examples are intentionally small. Combine them with your own VPC infrastructure and identity management.

Grant a single user access to a subnetwork

Most IAM configurations add individual users or service accounts to specific subnetworks without affecting other members or roles.

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

const member = new gcp.compute.SubnetworkIAMMember("member", {
    project: network_with_private_secondary_ip_ranges.project,
    region: network_with_private_secondary_ip_ranges.region,
    subnetwork: network_with_private_secondary_ip_ranges.name,
    role: "roles/compute.networkUser",
    member: "user:jane@example.com",
});

import pulumi
import pulumi_gcp as gcp

member = gcp.compute.SubnetworkIAMMember("member",
    project=network_with_private_secondary_ip_ranges["project"],
    region=network_with_private_secondary_ip_ranges["region"],
    subnetwork=network_with_private_secondary_ip_ranges["name"],
    role="roles/compute.networkUser",
    member="user:jane@example.com")

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := compute.NewSubnetworkIAMMember(ctx, "member", &compute.SubnetworkIAMMemberArgs{
			Project:    pulumi.Any(network_with_private_secondary_ip_ranges.Project),
			Region:     pulumi.Any(network_with_private_secondary_ip_ranges.Region),
			Subnetwork: pulumi.Any(network_with_private_secondary_ip_ranges.Name),
			Role:       pulumi.String("roles/compute.networkUser"),
			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.Compute.SubnetworkIAMMember("member", new()
    {
        Project = network_with_private_secondary_ip_ranges.Project,
        Region = network_with_private_secondary_ip_ranges.Region,
        Subnetwork = network_with_private_secondary_ip_ranges.Name,
        Role = "roles/compute.networkUser",
        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.compute.SubnetworkIAMMember;
import com.pulumi.gcp.compute.SubnetworkIAMMemberArgs;
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 SubnetworkIAMMember("member", SubnetworkIAMMemberArgs.builder()
            .project(network_with_private_secondary_ip_ranges.project())
            .region(network_with_private_secondary_ip_ranges.region())
            .subnetwork(network_with_private_secondary_ip_ranges.name())
            .role("roles/compute.networkUser")
            .member("user:jane@example.com")
            .build());

    }
}

resources:
  member:
    type: gcp:compute:SubnetworkIAMMember
    properties:
      project: ${["network-with-private-secondary-ip-ranges"].project}
      region: ${["network-with-private-secondary-ip-ranges"].region}
      subnetwork: ${["network-with-private-secondary-ip-ranges"].name}
      role: roles/compute.networkUser
      member: user:jane@example.com

The member property specifies the identity receiving access, using formats like “user:jane@example.com” or “serviceAccount:app@project.iam.gserviceaccount.com”. The role property defines the permission level. SubnetworkIAMMember is non-authoritative: it adds this one member without removing others who already have the role.

Add time-limited access with IAM Conditions

Temporary access grants expire automatically without manual cleanup, using IAM Conditions to set expiration dates or restrict access by time of day.

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

const member = new gcp.compute.SubnetworkIAMMember("member", {
    project: network_with_private_secondary_ip_ranges.project,
    region: network_with_private_secondary_ip_ranges.region,
    subnetwork: network_with_private_secondary_ip_ranges.name,
    role: "roles/compute.networkUser",
    member: "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

member = gcp.compute.SubnetworkIAMMember("member",
    project=network_with_private_secondary_ip_ranges["project"],
    region=network_with_private_secondary_ip_ranges["region"],
    subnetwork=network_with_private_secondary_ip_ranges["name"],
    role="roles/compute.networkUser",
    member="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/compute"
	"github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := compute.NewSubnetworkIAMMember(ctx, "member", &compute.SubnetworkIAMMemberArgs{
			Project:    pulumi.Any(network_with_private_secondary_ip_ranges.Project),
			Region:     pulumi.Any(network_with_private_secondary_ip_ranges.Region),
			Subnetwork: pulumi.Any(network_with_private_secondary_ip_ranges.Name),
			Role:       pulumi.String("roles/compute.networkUser"),
			Member:     pulumi.String("user:jane@example.com"),
			Condition: &compute.SubnetworkIAMMemberConditionArgs{
				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 member = new Gcp.Compute.SubnetworkIAMMember("member", new()
    {
        Project = network_with_private_secondary_ip_ranges.Project,
        Region = network_with_private_secondary_ip_ranges.Region,
        Subnetwork = network_with_private_secondary_ip_ranges.Name,
        Role = "roles/compute.networkUser",
        Member = "user:jane@example.com",
        Condition = new Gcp.Compute.Inputs.SubnetworkIAMMemberConditionArgs
        {
            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.compute.SubnetworkIAMMember;
import com.pulumi.gcp.compute.SubnetworkIAMMemberArgs;
import com.pulumi.gcp.compute.inputs.SubnetworkIAMMemberConditionArgs;
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 SubnetworkIAMMember("member", SubnetworkIAMMemberArgs.builder()
            .project(network_with_private_secondary_ip_ranges.project())
            .region(network_with_private_secondary_ip_ranges.region())
            .subnetwork(network_with_private_secondary_ip_ranges.name())
            .role("roles/compute.networkUser")
            .member("user:jane@example.com")
            .condition(SubnetworkIAMMemberConditionArgs.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:
  member:
    type: gcp:compute:SubnetworkIAMMember
    properties:
      project: ${["network-with-private-secondary-ip-ranges"].project}
      region: ${["network-with-private-secondary-ip-ranges"].region}
      subnetwork: ${["network-with-private-secondary-ip-ranges"].name}
      role: roles/compute.networkUser
      member: 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")

The condition block defines access constraints. The expression property uses Common Expression Language (CEL) to evaluate access rules at request time. Here, “request.time < timestamp(…)” denies access after midnight on 2019-12-31. The title and description properties document the condition’s purpose.

Grant a role to multiple members at once

When multiple users need the same permissions, SubnetworkIAMBinding manages the complete member list for a single role authoritatively.

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

const binding = new gcp.compute.SubnetworkIAMBinding("binding", {
    project: network_with_private_secondary_ip_ranges.project,
    region: network_with_private_secondary_ip_ranges.region,
    subnetwork: network_with_private_secondary_ip_ranges.name,
    role: "roles/compute.networkUser",
    members: ["user:jane@example.com"],
});

import pulumi
import pulumi_gcp as gcp

binding = gcp.compute.SubnetworkIAMBinding("binding",
    project=network_with_private_secondary_ip_ranges["project"],
    region=network_with_private_secondary_ip_ranges["region"],
    subnetwork=network_with_private_secondary_ip_ranges["name"],
    role="roles/compute.networkUser",
    members=["user:jane@example.com"])

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := compute.NewSubnetworkIAMBinding(ctx, "binding", &compute.SubnetworkIAMBindingArgs{
			Project:    pulumi.Any(network_with_private_secondary_ip_ranges.Project),
			Region:     pulumi.Any(network_with_private_secondary_ip_ranges.Region),
			Subnetwork: pulumi.Any(network_with_private_secondary_ip_ranges.Name),
			Role:       pulumi.String("roles/compute.networkUser"),
			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.Compute.SubnetworkIAMBinding("binding", new()
    {
        Project = network_with_private_secondary_ip_ranges.Project,
        Region = network_with_private_secondary_ip_ranges.Region,
        Subnetwork = network_with_private_secondary_ip_ranges.Name,
        Role = "roles/compute.networkUser",
        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.compute.SubnetworkIAMBinding;
import com.pulumi.gcp.compute.SubnetworkIAMBindingArgs;
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 SubnetworkIAMBinding("binding", SubnetworkIAMBindingArgs.builder()
            .project(network_with_private_secondary_ip_ranges.project())
            .region(network_with_private_secondary_ip_ranges.region())
            .subnetwork(network_with_private_secondary_ip_ranges.name())
            .role("roles/compute.networkUser")
            .members("user:jane@example.com")
            .build());

    }
}

resources:
  binding:
    type: gcp:compute:SubnetworkIAMBinding
    properties:
      project: ${["network-with-private-secondary-ip-ranges"].project}
      region: ${["network-with-private-secondary-ip-ranges"].region}
      subnetwork: ${["network-with-private-secondary-ip-ranges"].name}
      role: roles/compute.networkUser
      members:
        - user:jane@example.com

The members property lists all identities that should have this role. SubnetworkIAMBinding is authoritative for the specified role: it replaces any existing members with this list. Use SubnetworkIAMMember instead if you need to preserve other members or manage permissions incrementally.

Beyond these examples

These snippets focus on specific subnetwork IAM features: single-member and multi-member grants, and IAM Conditions for time-based access. They’re intentionally minimal rather than full access control configurations.

The examples reference pre-existing infrastructure such as VPC subnetworks (by name, project, and region). They focus on granting permissions rather than provisioning the underlying network resources.

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

  • Full policy management (SubnetworkIAMPolicy resource)
  • Service account and group identities
  • Federated identity and workload identity principals
  • Custom role definitions and organizational roles

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

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Frequently Asked Questions

Resource Selection & Conflicts
Which IAM resource should I use for managing subnetwork permissions?
Choose based on your needs: gcp.compute.SubnetworkIAMPolicy is authoritative and replaces the entire IAM policy, gcp.compute.SubnetworkIAMBinding is authoritative for a specific role (preserves other roles), and gcp.compute.SubnetworkIAMMember is non-authoritative (adds individual members without affecting others).
Can I use SubnetworkIAMPolicy with SubnetworkIAMBinding or SubnetworkIAMMember?
No, gcp.compute.SubnetworkIAMPolicy cannot be used with gcp.compute.SubnetworkIAMBinding or gcp.compute.SubnetworkIAMMember because they will conflict over the policy configuration.
Can I use SubnetworkIAMBinding and SubnetworkIAMMember together?
Yes, but only if they don’t grant privilege to the same role. Using both resources for the same role will cause conflicts.
IAM Configuration
What member identity formats are supported?
Supported formats include allUsers, allAuthenticatedUsers, user:{email}, serviceAccount:{email}, group:{email}, domain:{domain}, projectOwner:{projectid}, projectEditor:{projectid}, projectViewer:{projectid}, and federated identities like principal://iam.googleapis.com/....
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/my-custom-role.
Can I use IAM Conditions with subnetwork IAM resources?
Yes, all three resources support IAM Conditions, but be aware of known limitations. The condition property is immutable once set.
What properties are immutable after creation?
All core properties are immutable: member, role, subnetwork, project, region, and condition cannot be changed after resource creation.
Import & Migration
How do I import a subnetwork IAM resource with a custom role?
Use the full custom role name in your import command: [projects/my-project|organizations/my-org]/roles/my-custom-role. For example: pulumi import gcp:compute/subnetworkIAMMember:SubnetworkIAMMember editor "projects/my-project/regions/us-central1/subnetworks/my-subnet roles/my-custom-role user:jane@example.com".

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