Manage GCP Compute Region Disk IAM Policies

The gcp:compute/regionDiskIamPolicy:RegionDiskIamPolicy resource, part of the Pulumi GCP provider, controls IAM permissions for regional disks. Three related resources serve different use cases: RegionDiskIamPolicy replaces the entire policy, RegionDiskIamBinding manages all members for a specific role, and RegionDiskIamMember adds individual members. This guide focuses on three capabilities: authoritative policy replacement, role-level member binding, and incremental member addition.

These resources reference existing regional disks by project, region, and name. The examples are intentionally small. Combine them with your own disk resources and organizational IAM structure.

Replace the entire IAM policy for a regional disk

When you need complete control over disk access, you can set the entire IAM policy at once, replacing any existing permissions.

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

const admin = gcp.organizations.getIAMPolicy({
    bindings: [{
        role: "roles/viewer",
        members: ["user:jane@example.com"],
    }],
});
const policy = new gcp.compute.RegionDiskIamPolicy("policy", {
    project: regiondisk.project,
    region: regiondisk.region,
    name: regiondisk.name,
    policyData: admin.then(admin => admin.policyData),
});

import pulumi
import pulumi_gcp as gcp

admin = gcp.organizations.get_iam_policy(bindings=[{
    "role": "roles/viewer",
    "members": ["user:jane@example.com"],
}])
policy = gcp.compute.RegionDiskIamPolicy("policy",
    project=regiondisk["project"],
    region=regiondisk["region"],
    name=regiondisk["name"],
    policy_data=admin.policy_data)

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		admin, err := organizations.LookupIAMPolicy(ctx, &organizations.LookupIAMPolicyArgs{
			Bindings: []organizations.GetIAMPolicyBinding{
				{
					Role: "roles/viewer",
					Members: []string{
						"user:jane@example.com",
					},
				},
			},
		}, nil)
		if err != nil {
			return err
		}
		_, err = compute.NewRegionDiskIamPolicy(ctx, "policy", &compute.RegionDiskIamPolicyArgs{
			Project:    pulumi.Any(regiondisk.Project),
			Region:     pulumi.Any(regiondisk.Region),
			Name:       pulumi.Any(regiondisk.Name),
			PolicyData: pulumi.String(admin.PolicyData),
		})
		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 admin = Gcp.Organizations.GetIAMPolicy.Invoke(new()
    {
        Bindings = new[]
        {
            new Gcp.Organizations.Inputs.GetIAMPolicyBindingInputArgs
            {
                Role = "roles/viewer",
                Members = new[]
                {
                    "user:jane@example.com",
                },
            },
        },
    });

    var policy = new Gcp.Compute.RegionDiskIamPolicy("policy", new()
    {
        Project = regiondisk.Project,
        Region = regiondisk.Region,
        Name = regiondisk.Name,
        PolicyData = admin.Apply(getIAMPolicyResult => getIAMPolicyResult.PolicyData),
    });

});

package generated_program;

import com.pulumi.Context;
import com.pulumi.Pulumi;
import com.pulumi.core.Output;
import com.pulumi.gcp.organizations.OrganizationsFunctions;
import com.pulumi.gcp.organizations.inputs.GetIAMPolicyArgs;
import com.pulumi.gcp.compute.RegionDiskIamPolicy;
import com.pulumi.gcp.compute.RegionDiskIamPolicyArgs;
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) {
        final var admin = OrganizationsFunctions.getIAMPolicy(GetIAMPolicyArgs.builder()
            .bindings(GetIAMPolicyBindingArgs.builder()
                .role("roles/viewer")
                .members("user:jane@example.com")
                .build())
            .build());

        var policy = new RegionDiskIamPolicy("policy", RegionDiskIamPolicyArgs.builder()
            .project(regiondisk.project())
            .region(regiondisk.region())
            .name(regiondisk.name())
            .policyData(admin.policyData())
            .build());

    }
}

resources:
  policy:
    type: gcp:compute:RegionDiskIamPolicy
    properties:
      project: ${regiondisk.project}
      region: ${regiondisk.region}
      name: ${regiondisk.name}
      policyData: ${admin.policyData}
variables:
  admin:
    fn::invoke:
      function: gcp:organizations:getIAMPolicy
      arguments:
        bindings:
          - role: roles/viewer
            members:
              - user:jane@example.com

RegionDiskIamPolicy is authoritative: it replaces the disk’s entire IAM policy with the one you provide. The policyData comes from the getIAMPolicy data source, which constructs a policy from role-member bindings. This approach gives you full control but requires you to specify all desired permissions; any omitted roles or members are removed.

Grant a role to multiple members at once

When multiple users or service accounts need the same access level, you can bind them all to a single role without affecting other role assignments.

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

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

import pulumi
import pulumi_gcp as gcp

binding = gcp.compute.RegionDiskIamBinding("binding",
    project=regiondisk["project"],
    region=regiondisk["region"],
    name=regiondisk["name"],
    role="roles/viewer",
    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.NewRegionDiskIamBinding(ctx, "binding", &compute.RegionDiskIamBindingArgs{
			Project: pulumi.Any(regiondisk.Project),
			Region:  pulumi.Any(regiondisk.Region),
			Name:    pulumi.Any(regiondisk.Name),
			Role:    pulumi.String("roles/viewer"),
			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.RegionDiskIamBinding("binding", new()
    {
        Project = regiondisk.Project,
        Region = regiondisk.Region,
        Name = regiondisk.Name,
        Role = "roles/viewer",
        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.RegionDiskIamBinding;
import com.pulumi.gcp.compute.RegionDiskIamBindingArgs;
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 RegionDiskIamBinding("binding", RegionDiskIamBindingArgs.builder()
            .project(regiondisk.project())
            .region(regiondisk.region())
            .name(regiondisk.name())
            .role("roles/viewer")
            .members("user:jane@example.com")
            .build());

    }
}

resources:
  binding:
    type: gcp:compute:RegionDiskIamBinding
    properties:
      project: ${regiondisk.project}
      region: ${regiondisk.region}
      name: ${regiondisk.name}
      role: roles/viewer
      members:
        - user:jane@example.com

RegionDiskIamBinding is authoritative for the specified role: it replaces all members for that role but preserves other roles on the disk. The members property accepts a list of identities (users, service accounts, groups). This resource cannot be used with RegionDiskIamPolicy on the same disk, as they would conflict over policy ownership.

Add a single member to a role incrementally

When you need to grant access to one additional user without disturbing existing permissions, you can add individual members to roles.

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

const member = new gcp.compute.RegionDiskIamMember("member", {
    project: regiondisk.project,
    region: regiondisk.region,
    name: regiondisk.name,
    role: "roles/viewer",
    member: "user:jane@example.com",
});

import pulumi
import pulumi_gcp as gcp

member = gcp.compute.RegionDiskIamMember("member",
    project=regiondisk["project"],
    region=regiondisk["region"],
    name=regiondisk["name"],
    role="roles/viewer",
    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.NewRegionDiskIamMember(ctx, "member", &compute.RegionDiskIamMemberArgs{
			Project: pulumi.Any(regiondisk.Project),
			Region:  pulumi.Any(regiondisk.Region),
			Name:    pulumi.Any(regiondisk.Name),
			Role:    pulumi.String("roles/viewer"),
			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.RegionDiskIamMember("member", new()
    {
        Project = regiondisk.Project,
        Region = regiondisk.Region,
        Name = regiondisk.Name,
        Role = "roles/viewer",
        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.RegionDiskIamMember;
import com.pulumi.gcp.compute.RegionDiskIamMemberArgs;
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 RegionDiskIamMember("member", RegionDiskIamMemberArgs.builder()
            .project(regiondisk.project())
            .region(regiondisk.region())
            .name(regiondisk.name())
            .role("roles/viewer")
            .member("user:jane@example.com")
            .build());

    }
}

resources:
  member:
    type: gcp:compute:RegionDiskIamMember
    properties:
      project: ${regiondisk.project}
      region: ${regiondisk.region}
      name: ${regiondisk.name}
      role: roles/viewer
      member: user:jane@example.com

RegionDiskIamMember is non-authoritative: it adds one member to a role while preserving all other members for that role and all other roles on the disk. The member property accepts a single identity. You can use multiple RegionDiskIamMember resources together, or combine them with RegionDiskIamBinding resources as long as they don’t target the same role.

Beyond these examples

These snippets focus on specific IAM management approaches: authoritative policy replacement, role-level member binding, and incremental member addition. They’re intentionally minimal rather than full access control configurations.

The examples reference pre-existing infrastructure such as regional disks (by project, region, and name). They focus on IAM permission assignment rather than disk provisioning.

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

Conditional IAM bindings (condition blocks)
Service account impersonation
Custom role definitions
Policy conflict resolution between resource types

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 RegionDiskIamPolicy resource reference for all available configuration options.

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Frequently Asked Questions

Resource Selection & Compatibility

What's the difference between RegionDiskIamPolicy, RegionDiskIamBinding, and RegionDiskIamMember?

RegionDiskIamPolicy is authoritative and replaces the entire IAM policy. RegionDiskIamBinding is authoritative for a specific role, preserving other roles. RegionDiskIamMember is non-authoritative, adding a single member while preserving other members for that role.

Can I use RegionDiskIamPolicy with RegionDiskIamBinding or RegionDiskIamMember?

No, RegionDiskIamPolicy cannot be used with RegionDiskIamBinding or RegionDiskIamMember because they will conflict over the policy configuration.

Can I use RegionDiskIamBinding and RegionDiskIamMember together?

Yes, but only if they manage different roles. Using both on the same role will cause conflicts.

Configuration & Properties

What does authoritative mean for IAM resources?

Authoritative resources replace existing configuration. RegionDiskIamPolicy replaces the entire policy, while RegionDiskIamBinding replaces all members for a specific role. Non-authoritative RegionDiskIamMember only adds members without removing existing ones.

Which properties are immutable after creation?

The name, project, and region properties cannot be changed after the resource is created.

How do I generate the policyData for RegionDiskIamPolicy?

Use the gcp.organizations.getIAMPolicy data source to generate the policyData value, as shown in the examples.

Import & Migration

What formats can I use to import a RegionDiskIamPolicy?

You can use several formats: projects/{{project}}/regions/{{region}}/disks/{{name}}, {{project}}/{{region}}/{{name}}, {{region}}/{{name}}, or just {{name}}. Missing values are taken from the provider configuration.

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