Manage GCP Cloud Storage Folder IAM Bindings

The gcp:storage/managedFolderIamBinding:ManagedFolderIamBinding resource, part of the Pulumi GCP provider, grants IAM roles to members for Cloud Storage managed folders, controlling who can access folder contents. This guide focuses on three capabilities: binding roles to multiple members, time-based conditional access, and non-authoritative member addition.

ManagedFolderIamBinding is one of three IAM resources for managed folders. It’s authoritative for a given role, meaning it replaces the member list for that role while preserving other roles. The examples are intentionally small. Combine them with your own bucket and managed folder infrastructure.

Grant a role to multiple members at once

Teams managing access often need to assign 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.storage.ManagedFolderIamBinding("binding", {
    bucket: folder.bucket,
    managedFolder: folder.name,
    role: "roles/storage.admin",
    members: ["user:jane@example.com"],
});

import pulumi
import pulumi_gcp as gcp

binding = gcp.storage.ManagedFolderIamBinding("binding",
    bucket=folder["bucket"],
    managed_folder=folder["name"],
    role="roles/storage.admin",
    members=["user:jane@example.com"])

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := storage.NewManagedFolderIamBinding(ctx, "binding", &storage.ManagedFolderIamBindingArgs{
			Bucket:        pulumi.Any(folder.Bucket),
			ManagedFolder: pulumi.Any(folder.Name),
			Role:          pulumi.String("roles/storage.admin"),
			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.Storage.ManagedFolderIamBinding("binding", new()
    {
        Bucket = folder.Bucket,
        ManagedFolder = folder.Name,
        Role = "roles/storage.admin",
        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.storage.ManagedFolderIamBinding;
import com.pulumi.gcp.storage.ManagedFolderIamBindingArgs;
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 ManagedFolderIamBinding("binding", ManagedFolderIamBindingArgs.builder()
            .bucket(folder.bucket())
            .managedFolder(folder.name())
            .role("roles/storage.admin")
            .members("user:jane@example.com")
            .build());

    }
}

resources:
  binding:
    type: gcp:storage:ManagedFolderIamBinding
    properties:
      bucket: ${folder.bucket}
      managedFolder: ${folder.name}
      role: roles/storage.admin
      members:
        - user:jane@example.com

The members property accepts a list of identities in specific formats: user:{email}, serviceAccount:{email}, group:{email}, or special identifiers like allUsers. The binding replaces any existing members for this role on the managed folder, but leaves other roles untouched.

Add time-based access with IAM Conditions

Temporary access grants are common when contractors or external teams need limited-duration permissions.

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

const binding = new gcp.storage.ManagedFolderIamBinding("binding", {
    bucket: folder.bucket,
    managedFolder: folder.name,
    role: "roles/storage.admin",
    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.storage.ManagedFolderIamBinding("binding",
    bucket=folder["bucket"],
    managed_folder=folder["name"],
    role="roles/storage.admin",
    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/storage"
	"github.com/pulumi/pulumi/sdk/v3/go/pulumi"
)

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := storage.NewManagedFolderIamBinding(ctx, "binding", &storage.ManagedFolderIamBindingArgs{
			Bucket:        pulumi.Any(folder.Bucket),
			ManagedFolder: pulumi.Any(folder.Name),
			Role:          pulumi.String("roles/storage.admin"),
			Members: pulumi.StringArray{
				pulumi.String("user:jane@example.com"),
			},
			Condition: &storage.ManagedFolderIamBindingConditionArgs{
				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.Storage.ManagedFolderIamBinding("binding", new()
    {
        Bucket = folder.Bucket,
        ManagedFolder = folder.Name,
        Role = "roles/storage.admin",
        Members = new[]
        {
            "user:jane@example.com",
        },
        Condition = new Gcp.Storage.Inputs.ManagedFolderIamBindingConditionArgs
        {
            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.storage.ManagedFolderIamBinding;
import com.pulumi.gcp.storage.ManagedFolderIamBindingArgs;
import com.pulumi.gcp.storage.inputs.ManagedFolderIamBindingConditionArgs;
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 ManagedFolderIamBinding("binding", ManagedFolderIamBindingArgs.builder()
            .bucket(folder.bucket())
            .managedFolder(folder.name())
            .role("roles/storage.admin")
            .members("user:jane@example.com")
            .condition(ManagedFolderIamBindingConditionArgs.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:storage:ManagedFolderIamBinding
    properties:
      bucket: ${folder.bucket}
      managedFolder: ${folder.name}
      role: roles/storage.admin
      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 let you add time-based or attribute-based restrictions to role bindings. The expression property uses CEL (Common Expression Language) to define when the binding is active. Here, the role expires at midnight on 2019-12-31. The title and description help identify the condition’s purpose.

Add a single member to an existing role

When you need to grant access to one additional user without affecting existing members, use ManagedFolderIamMember for non-authoritative updates.

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

const member = new gcp.storage.ManagedFolderIamMember("member", {
    bucket: folder.bucket,
    managedFolder: folder.name,
    role: "roles/storage.admin",
    member: "user:jane@example.com",
});

import pulumi
import pulumi_gcp as gcp

member = gcp.storage.ManagedFolderIamMember("member",
    bucket=folder["bucket"],
    managed_folder=folder["name"],
    role="roles/storage.admin",
    member="user:jane@example.com")

package main

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

func main() {
	pulumi.Run(func(ctx *pulumi.Context) error {
		_, err := storage.NewManagedFolderIamMember(ctx, "member", &storage.ManagedFolderIamMemberArgs{
			Bucket:        pulumi.Any(folder.Bucket),
			ManagedFolder: pulumi.Any(folder.Name),
			Role:          pulumi.String("roles/storage.admin"),
			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.Storage.ManagedFolderIamMember("member", new()
    {
        Bucket = folder.Bucket,
        ManagedFolder = folder.Name,
        Role = "roles/storage.admin",
        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.storage.ManagedFolderIamMember;
import com.pulumi.gcp.storage.ManagedFolderIamMemberArgs;
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 ManagedFolderIamMember("member", ManagedFolderIamMemberArgs.builder()
            .bucket(folder.bucket())
            .managedFolder(folder.name())
            .role("roles/storage.admin")
            .member("user:jane@example.com")
            .build());

    }
}

resources:
  member:
    type: gcp:storage:ManagedFolderIamMember
    properties:
      bucket: ${folder.bucket}
      managedFolder: ${folder.name}
      role: roles/storage.admin
      member: user:jane@example.com

Unlike ManagedFolderIamBinding, which replaces the entire member list for a role, ManagedFolderIamMember adds a single member without disturbing others. The member property takes one identity in the same formats as the members list. This resource is useful when multiple teams manage access independently.

Beyond these examples

These snippets focus on specific IAM binding features: role binding with multiple members, conditional access with time-based expiration, and non-authoritative member addition. They’re intentionally minimal rather than full access control configurations.

The examples reference pre-existing infrastructure such as Cloud Storage buckets with managed folders. They focus on configuring IAM bindings rather than provisioning the storage resources themselves.

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

  • Full IAM policy replacement (ManagedFolderIamPolicy)
  • Custom role definitions and formatting
  • Service account and group identity management
  • IAM Condition limitations and troubleshooting

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

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Frequently Asked Questions

Resource Selection & Conflicts
What's the difference between ManagedFolderIamPolicy, ManagedFolderIamBinding, and ManagedFolderIamMember?
ManagedFolderIamPolicy is fully authoritative and replaces the entire IAM policy. ManagedFolderIamBinding is authoritative for a specific role, preserving other roles. ManagedFolderIamMember is non-authoritative, adding individual members while preserving existing members for that role.
Can I use ManagedFolderIamPolicy together with ManagedFolderIamBinding or ManagedFolderIamMember?
No, ManagedFolderIamPolicy cannot be used with ManagedFolderIamBinding or ManagedFolderIamMember because they will conflict over the policy configuration.
Can I use ManagedFolderIamBinding and ManagedFolderIamMember together?
Yes, but only if they don’t grant privileges to the same role. If both resources manage the same role, they will conflict.
Configuration & Setup
How do I specify a custom IAM role?
Custom roles must use the full path format: [projects|organizations]/{parent-name}/roles/{role-name} (e.g., projects/my-project/roles/my-custom-role).
What member identity formats are supported?
Supported formats include allUsers, allAuthenticatedUsers, user:{email}, serviceAccount:{email}, group:{email}, domain:{domain}, projectOwner:projectid, projectEditor:projectid, and projectViewer:projectid.
What properties can't be changed after creation?
The bucket, managedFolder, role, and condition properties are immutable and cannot be modified after the resource is created.
Advanced Features
Can I use IAM Conditions with this resource?
Yes, IAM Conditions are supported using the condition property with title, description, and expression fields. However, IAM Conditions have known limitations that may affect certain use cases.
How do I add time-based access restrictions?
Use the condition property with an expression like request.time < timestamp("2020-01-01T00:00:00Z") to create time-based access policies.
Import & Migration
What format should I use when importing IAM bindings?
Use space-delimited identifiers: "b/{{bucket}}/managedFolders/{{managed_folder}} roles/storage.objectViewer" for bindings, or add the member identity for member imports.
How do I import a resource with a custom role?
Use the full custom role path in the import command: [projects/my-project|organizations/my-org]/roles/my-custom-role instead of just the role name.

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