Google Compute Engine Subnetwork IAM

This page shows how to write Terraform for Compute Engine Subnetwork IAM and write them securely.

google_compute_subnetwork_iam (Terraform)

The Subnetwork IAM in Compute Engine can be configured in Terraform with the resource name google_compute_subnetwork_iam. The following sections describe how to use the resource and its parameters.

Example Usage from GitHub

An example could not be found in GitHub.

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Parameters

The following arguments are supported:

  • subnetwork - (Required) Used to find the parent resource to bind the IAM policy to

  • region - (Optional) The GCP region for this subnetwork. Used to find the parent resource to bind the IAM policy to. If not specified, the value will be parsed from the identifier of the parent resource. If no region is provided in the parent identifier and no region is specified, it is taken from the provider configuration.

  • project - (Optional) The ID of the project in which the resource belongs. If it is not provided, the project will be parsed from the identifier of the parent resource. If no project is provided in the parent identifier and no project is specified, the provider project is used.

  • member/members - (Required) Identities that will be granted the privilege in role. Each entry can have one of the following values:

    • allUsers: A special identifier that represents anyone who is on the internet; with or without a Google account.
    • allAuthenticatedUsers: A special identifier that represents anyone who is authenticated with a Google account or a service account.
    • user:[emailid]: An email address that represents a specific Google account. For example, alice@gmail.com or joe@example.com.
    • serviceAccount:[emailid]: An email address that represents a service account. For example, my-other-app@appspot.gserviceaccount.com.
    • group:[emailid]: An email address that represents a Google group. For example, admins@example.com.
    • domain:[domain]: A G Suite domain (primary, instead of alias) name that represents all the users of that domain. For example, google.com or example.com.
    • projectOwner:projectid: Owners of the given project. For example, "projectOwner:my-example-project"
    • projectEditor:projectid: Editors of the given project. For example, "projectEditor:my-example-project"
    • projectViewer:projectid: Viewers of the given project. For example, "projectViewer:my-example-project"
  • role - (Required) The role that should be applied. Only one google_compute_subnetwork_iam_binding can be used per role. Note that custom roles must be of the format [projects|organizations]/[parent-name]/roles/[role-name].

  • policy_data - (Required only by google_compute_subnetwork_iam_policy) The policy data generated by a google_iam_policy data source.

  • condition - (Optional, Beta) An IAM Condition for a given binding. Structure is documented below.


The condition block supports:

  • expression - (Required) Textual representation of an expression in Common Expression Language syntax.

  • title - (Required) A title for the expression, i.e. a short string describing its purpose.

  • description - (Optional) An optional description of the expression. This is a longer text which describes the expression, e.g. when hovered over it in a UI.

Warning: Terraform considers the role and condition contents (title+description+expression) as the identifier for the binding. This means that if any part of the condition is changed out-of-band, Terraform will consider it to be an entirely different resource and will treat it as such.

In addition to the arguments listed above, the following computed attributes are exported:

  • etag - (Computed) The etag of the IAM policy.

Explanation in Terraform Registry

Three different resources help you manage your IAM policy for Compute Engine Subnetwork. Each of these resources serves a different use case:

  • google_compute_subnetwork_iam_policy: Authoritative. Sets the IAM policy for the subnetwork and replaces any existing policy already attached.
  • google_compute_subnetwork_iam_binding: Authoritative for a given role. Updates the IAM policy to grant a role to a list of members. Other roles within the IAM policy for the subnetwork are preserved.
  • google_compute_subnetwork_iam_member: Non-authoritative. Updates the IAM policy to grant a role to a new member. Other members for the role for the subnetwork are preserved.

    Note: google_compute_subnetwork_iam_policy cannot be used in conjunction with google_compute_subnetwork_iam_binding and google_compute_subnetwork_iam_member or they will fight over what your policy should be.

    Note: google_compute_subnetwork_iam_binding resources can be used in conjunction with google_compute_subnetwork_iam_member resources only if they do not grant privilege to the same role.

    Note: This resource supports IAM Conditions (beta) but they have some known limitations which can be found here. Please review this article if you are having issues with IAM Conditions.

Tips: Best Practices for The Other Google Compute Engine Resources

In addition to the google_compute_disk, Google Compute Engine has the other resources that should be configured for security reasons. Please check some examples of those resources and precautions.

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google_compute_disk

Ensure the encryption key for your GCE disk is stored securely

It is better to store the encryption key for your GCE disk securely. Secret Manager could be used instead.

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google_compute_firewall

Ensure your VPC firewall blocks unwanted outbound traffic

It is better to block unwanted outbound traffic not to expose resources in the VPC to unwanted attacks.

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google_compute_instance

Ensure appropriate service account is assigned to your GCE instance

It is better to create a custom service account for the instance and assign it.

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google_compute_project_metadata

Ensure OS login for your GCE instances is enabled at project level

It is better to enable OS login for your GCE instances. Enabling OS login ensures that SSH keys used to connect to instances are mapped with IAM users, allowing centralized and automated SSH key management.

risk-label

google_compute_ssl_policy

Ensure to use modern TLS protocols

It's better to adopt TLS v1.2+ instead of outdated TLS protocols.

risk-label

google_compute_subnetwork

Ensure VPC flow logging is enabled

It is better to enable VPC flow logging. VPC flow logging allows us to audit traffic in your network.

Review your Google Compute Engine settings

In addition to the above, there are other security points you should be aware of making sure that your .tf files are protected in Shisho Cloud.

Frequently asked questions

What is Google Compute Engine Subnetwork IAM?

Google Compute Engine Subnetwork IAM is a resource for Compute Engine of Google Cloud Platform. Settings can be wrote in Terraform.

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