# Google Compute Engine VM module

This module can operate in two distinct modes:

- instance creation, with optional unmanaged group
- instance template creation

In both modes, an optional service account can be created and assigned to either instances or template. If you need a managed instance group when using the module in template mode, refer to the [`compute-mig`](../compute-mig) module.

## Examples

### Instance leveraging defaults

The simplest example leverages defaults for the boot disk image and size, and uses a service account created by the module. Multiple instances can be managed via the `instance_count` variable.

```hcl
module "simple-vm-example" {
  source     = "../modules/compute-vm"
  project_id = "my-project"
  region     = "europe-west1"
  zone       = "europe-west1-b"
  name       = "test"
  network_interfaces = [{
    network    = local.network_self_link,
    subnetwork = local.subnet_self_link,
    nat        = false,
    addresses  = null
  }]
  service_account_create = true
  instance_count = 1
}
```

### Instance template

This example shows how to use the module to manage an instance template that defines an additional attached disk for each instance, and overrides defaults for the boot disk image and service account.

```hcl
module "debian-test" {
  source     = "../modules/compute-vm"
  project_id = "my-project"
  region     = "europe-west1"
  zone       = "europe-west1-b"
  name       = "test"
  network_interfaces = [{
    network    = local.network_self_link,
    subnetwork = local.subnet_self_link,
    nat        = false,
    addresses  = null
  }]
  instance_count = 1
  boot_disk      = {
    image = "projects/cos-cloud/global/images/family/cos-stable"
    type  = "pd-ssd"
    size  = 10
  }
  attached_disks = [
    { name = "disk-1", size = 10, image = null, options = null }
  ]
  service_account        = "vm-default@my-project.iam.gserviceaccount.com"
  use_instance_template  = true
}
```

### Instance group

If an instance group is needed when operating in instance mode, simply set the `group` variable to a non null map. The map can contain named port declarations, or be empty if named ports are not needed.

```hcl
module "instance-group" {
  source     = "../../cloud-foundation-fabric/modules/compute-vm"
  project_id = "my-project"
  region     = "europe-west1"
  zone       = "europe-west1-b"
  name       = "ilb-test"
  network_interfaces = [{
    network    = local.network_self_link,
    subnetwork = local.subnetwork_self_link,
    nat        = false,
    addresses  = null
  }]
  boot_disk = {
    image = "projects/cos-cloud/global/images/family/cos-stable"
    type  = "pd-ssd"
    size  = 10
  }
  service_account        = local.service_account_email
  service_account_scopes = ["https://www.googleapis.com/auth/cloud-platform"]
  use_instance_template  = true
  metadata = {
    user-data = local.cloud_config
  }
  group = {}
}

```

<!-- BEGIN TFDOC -->
## Variables

| name | description | type | required | default |
|---|---|:---: |:---:|:---:|
| name | Instances base name. | <code title="">string</code> | ✓ |  |
| network_interfaces | Network interfaces configuration. Use self links for Shared VPC, set addresses to null if not needed. | <code title="list&#40;object&#40;&#123;&#10;nat        &#61; bool&#10;network    &#61; string&#10;subnetwork &#61; string&#10;addresses &#61; object&#40;&#123;&#10;internal &#61; list&#40;string&#41;&#10;external &#61; list&#40;string&#41;&#10;&#125;&#41;&#10;&#125;&#41;&#41;">list(object({...}))</code> | ✓ |  |
| project_id | Project id. | <code title="">string</code> | ✓ |  |
| region | Compute region. | <code title="">string</code> | ✓ |  |
| zone | Compute zone. | <code title="">string</code> | ✓ |  |
| *attached_disk_defaults* | Defaults for attached disks options. | <code title="object&#40;&#123;&#10;auto_delete &#61; bool&#10;mode        &#61; string&#10;type &#61; string&#10;source      &#61; string&#10;&#125;&#41;">object({...})</code> |  | <code title="&#123;&#10;auto_delete &#61; true&#10;source      &#61; null&#10;mode        &#61; &#34;READ_WRITE&#34;&#10;type &#61; &#34;pd-ssd&#34;&#10;&#125;">...</code> |
| *attached_disks* | Additional disks, if options is null defaults will be used in its place. | <code title="list&#40;object&#40;&#123;&#10;name  &#61; string&#10;image &#61; string&#10;size  &#61; string&#10;options &#61; object&#40;&#123;&#10;auto_delete &#61; bool&#10;mode        &#61; string&#10;source      &#61; string&#10;type &#61; string&#10;&#125;&#41;&#10;&#125;&#41;&#41;">list(object({...}))</code> |  | <code title="">[]</code> |
| *boot_disk* | Boot disk properties. | <code title="object&#40;&#123;&#10;image &#61; string&#10;size  &#61; number&#10;type &#61; string&#10;&#125;&#41;">object({...})</code> |  | <code title="&#123;&#10;image &#61; &#34;projects&#47;debian-cloud&#47;global&#47;images&#47;family&#47;debian-10&#34;&#10;type &#61; &#34;pd-ssd&#34;&#10;size  &#61; 10&#10;&#125;">...</code> |
| *group* | Define this variable to create an instance group for instances. Disabled for template use. | <code title="object&#40;&#123;&#10;named_ports &#61; map&#40;number&#41;&#10;&#125;&#41;">object({...})</code> |  | <code title="">null</code> |
| *hostname* | Instance FQDN name. | <code title="">string</code> |  | <code title="">null</code> |
| *instance_count* | Number of instances to create (only for non-template usage). | <code title="">number</code> |  | <code title="">1</code> |
| *instance_type* | Instance type. | <code title="">string</code> |  | <code title="">f1-micro</code> |
| *labels* | Instance labels. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">{}</code> |
| *metadata* | Instance metadata. | <code title="map&#40;string&#41;">map(string)</code> |  | <code title="">{}</code> |
| *min_cpu_platform* | Minimum CPU platform. | <code title="">string</code> |  | <code title="">null</code> |
| *options* | Instance options. | <code title="object&#40;&#123;&#10;allow_stopping_for_update &#61; bool&#10;can_ip_forward            &#61; bool&#10;deletion_protection       &#61; bool&#10;preemptible               &#61; bool&#10;&#125;&#41;">object({...})</code> |  | <code title="&#123;&#10;allow_stopping_for_update &#61; true&#10;can_ip_forward            &#61; false&#10;deletion_protection       &#61; false&#10;preemptible               &#61; false&#10;&#125;">...</code> |
| *scratch_disks* | Scratch disks configuration. | <code title="object&#40;&#123;&#10;count     &#61; number&#10;interface &#61; string&#10;&#125;&#41;">object({...})</code> |  | <code title="&#123;&#10;count     &#61; 0&#10;interface &#61; &#34;NVME&#34;&#10;&#125;">...</code> |
| *service_account* | Service account email. Unused if service account is auto-created. | <code title="">string</code> |  | <code title="">null</code> |
| *service_account_create* | Auto-create service account. | <code title="">bool</code> |  | <code title="">false</code> |
| *service_account_scopes* | Scopes applied to service account. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
| *tags* | Instance tags. | <code title="list&#40;string&#41;">list(string)</code> |  | <code title="">[]</code> |
| *use_instance_template* | Create instance template instead of instances. | <code title="">bool</code> |  | <code title="">false</code> |

## Outputs

| name | description | sensitive |
|---|---|:---:|
| external_ips | Instance main interface external IP addresses. |  |
| group | Instance group resource. |  |
| instances | Instance resources. |  |
| internal_ips | Instance main interface internal IP addresses. |  |
| names | Instance names. |  |
| self_links | Instance self links. |  |
| service_account | Service account resource. |  |
| service_account_email | Service account email. |  |
| service_account_iam_email | Service account email. |  |
| template | Template resource. |  |
| template_name | Template name. |  |
<!-- END TFDOC -->

## TODO

- [ ] add support for instance groups