Manage GCP Compute Disk IAM Permissions

The gcp:compute/diskIamMember:DiskIamMember resource, part of the Pulumi GCP provider, manages IAM permissions for Compute Engine disks by adding individual members to roles without affecting other permissions. This guide focuses on three approaches: adding single members (DiskIamMember), managing complete role membership (DiskIamBinding), and replacing entire policies (DiskIamPolicy).

These resources reference existing Compute Engine disks and require IAM permissions in your GCP project. The examples are intentionally small. Combine them with your own disk resources and organizational IAM structure.

Grant a single user access to a disk

Most IAM configurations add individual users or service accounts to specific roles incrementally.

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

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

import pulumi
import pulumi_gcp as gcp

member = gcp.compute.DiskIamMember("member",
    project=default["project"],
    zone=default["zone"],
    name=default["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.NewDiskIamMember(ctx, "member", &compute.DiskIamMemberArgs{
			Project: pulumi.Any(_default.Project),
			Zone:    pulumi.Any(_default.Zone),
			Name:    pulumi.Any(_default.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.DiskIamMember("member", new()
    {
        Project = @default.Project,
        Zone = @default.Zone,
        Name = @default.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.DiskIamMember;
import com.pulumi.gcp.compute.DiskIamMemberArgs;
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 DiskIamMember("member", DiskIamMemberArgs.builder()
            .project(default_.project())
            .zone(default_.zone())
            .name(default_.name())
            .role("roles/viewer")
            .member("user:jane@example.com")
            .build());

    }
}

resources:
  member:
    type: gcp:compute:DiskIamMember
    properties:
      project: ${default.project}
      zone: ${default.zone}
      name: ${default.name}
      role: roles/viewer
      member: user:jane@example.com

The member property specifies one identity (user, service account, group, or domain). The role property defines the permission level. DiskIamMember is non-authoritative: it adds this member to the role without removing other members or affecting other roles on the disk.

Grant multiple users the same role

When multiple users need identical permissions, you can manage them as a group.

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

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

import pulumi
import pulumi_gcp as gcp

binding = gcp.compute.DiskIamBinding("binding",
    project=default["project"],
    zone=default["zone"],
    name=default["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.NewDiskIamBinding(ctx, "binding", &compute.DiskIamBindingArgs{
			Project: pulumi.Any(_default.Project),
			Zone:    pulumi.Any(_default.Zone),
			Name:    pulumi.Any(_default.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.DiskIamBinding("binding", new()
    {
        Project = @default.Project,
        Zone = @default.Zone,
        Name = @default.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.DiskIamBinding;
import com.pulumi.gcp.compute.DiskIamBindingArgs;
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 DiskIamBinding("binding", DiskIamBindingArgs.builder()
            .project(default_.project())
            .zone(default_.zone())
            .name(default_.name())
            .role("roles/viewer")
            .members("user:jane@example.com")
            .build());

    }
}

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

The members property lists all identities that should have this role. DiskIamBinding is authoritative for the specified role: it replaces any existing members for that role while preserving other roles. You can use multiple DiskIamBinding resources on the same disk as long as they manage different roles.

Replace the entire IAM policy for a disk

Some workflows require complete control over all IAM bindings.

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.DiskIamPolicy("policy", {
    project: _default.project,
    zone: _default.zone,
    name: _default.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.DiskIamPolicy("policy",
    project=default["project"],
    zone=default["zone"],
    name=default["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.NewDiskIamPolicy(ctx, "policy", &compute.DiskIamPolicyArgs{
			Project:    pulumi.Any(_default.Project),
			Zone:       pulumi.Any(_default.Zone),
			Name:       pulumi.Any(_default.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.DiskIamPolicy("policy", new()
    {
        Project = @default.Project,
        Zone = @default.Zone,
        Name = @default.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.DiskIamPolicy;
import com.pulumi.gcp.compute.DiskIamPolicyArgs;
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 DiskIamPolicy("policy", DiskIamPolicyArgs.builder()
            .project(default_.project())
            .zone(default_.zone())
            .name(default_.name())
            .policyData(admin.policyData())
            .build());

    }
}

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

The policyData property accepts output from getIAMPolicy, which defines all roles and members in a single policy document. DiskIamPolicy is authoritative for the entire policy: it replaces all existing bindings. This resource cannot coexist with DiskIamBinding or DiskIamMember on the same disk, as they will conflict over policy ownership.

Beyond these examples

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

The examples reference pre-existing infrastructure such as Compute Engine disks in specified zones and GCP projects with IAM permissions. They focus on configuring IAM bindings rather than provisioning the underlying disk resources.

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

Conditional IAM bindings (condition property)
Custom role definitions
Federated identity configuration
Cross-project or cross-organization access

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 Compute Disk IAM Member resource reference for all available configuration options.

Let's manage GCP Compute Disk IAM Permissions

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Frequently Asked Questions

Resource Selection & Conflicts

Which IAM resource should I use for managing disk permissions?

Choose based on your needs:

gcp.compute.DiskIamPolicy: Authoritative control, replaces the entire IAM policy
gcp.compute.DiskIamBinding: Authoritative for a specific role, preserves other roles
gcp.compute.DiskIamMember: Non-authoritative, adds a single member while preserving other members for that role

Why am I seeing IAM policy conflicts with my disk resources?

gcp.compute.DiskIamPolicy cannot be used with gcp.compute.DiskIamBinding or gcp.compute.DiskIamMember as they fight over policy control. Choose one approach: use DiskIamPolicy alone for full control, or use DiskIamBinding/DiskIamMember for granular management.

Can I use DiskIamBinding and DiskIamMember together?

Yes, but only if they manage different roles. Using both resources for the same role causes conflicts.

Configuration & Identity Formats

What member identity formats can I use?

Supported formats include:

Public access: allUsers, allAuthenticatedUsers
Specific identities: user:{email}, serviceAccount:{email}, group:{email}, domain:{domain}
Project roles: projectOwner:{projectid}, projectEditor:{projectid}, projectViewer:{projectid}
Federated identities: Workload/workforce identity pools (see Principal identifiers documentation)

How do I specify a custom IAM role?

Custom roles must use the format [projects|organizations]/{parent-name}/roles/{role-name}. This format is required both when creating resources and importing them.

Immutability & Updates

What happens if I need to change the role or member?

All properties are immutable: member, role, name, project, zone, and condition. Any changes require replacing the resource.

Using a different cloud?

Explore security guides for other cloud providers:

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