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Building VMs with Cloud-Init

NetActuate VMs support cloud-init and bash scripts passed at build time via the build API. Use this to bootstrap configuration, install packages, write files, and run commands automatically when a VM first boots — without requiring post-boot SSH access.

How It Works​

When you include script_type and script_content in a VM build request, NetActuate passes the script to the VM via the hypervisor at first boot. The script runs before the VM is reachable via SSH.

The script_content parameter must be base64-encoded. The script_type parameter tells the platform how to interpret the content.

Supported Script Types​

script_type valueFormat
cloud-initCloud-init YAML (recommended)
cloud_initAlias for cloud-init
user-dataAlias for cloud-init
user_dataAlias for cloud-init
bashBash shell script

Note: Not all OS images support cloud-init. Ubuntu 24.04 LTS and most modern Linux images do. Verify your image supports the script type before using this feature.

Cloud-Init Example​

Write your cloud-init YAML, then base64-encode it before passing it to the API.

Cloud-init YAML (before encoding):

#cloud-config
packages:
  - nginx
  - curl

runcmd:
  - systemctl enable nginx
  - systemctl start nginx

write_files:
  - path: /etc/app/config.env
    permissions: '0600'
    content: |
      APP_ENV=production

Encode and build:

SCRIPT=$(base64 < cloud-init.yaml)

curl -X POST https://vapi2.netactuate.com/api/build \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "mbpkgid": 1001,
    "location": 12,
    "image": 203,
    "fqdn": "web01.example.com",
    "ssh_key_id": 88,
    "script_type": "cloud-init",
    "script_content": "'"$SCRIPT"'"
  }'

Bash Script Example​

#!/bin/bash
apt-get update -y
apt-get install -y nginx
systemctl enable nginx
systemctl start nginx

Encode and pass with "script_type": "bash".

Combining with Secrets Manager​

Cloud-init content can reference secrets stored in NetActuate Secrets Manager using template syntax. Substitution happens server-side before the script reaches the VM.

#cloud-config
write_files:
  - path: /etc/app/config.env
    permissions: '0600'
    content: |
      DB_PASSWORD=${{secret.DB_PASSWORD}}
      API_KEY=${{secret.API_KEY}}

runcmd:
  - systemctl restart myapp

See Using Secrets Manager with Cloud-Init for the full workflow including creating secrets.

Using Cloud-Init with Ansible​

Pass script_content through the netactuate.compute.node module:

- name: Provision VM with cloud-init
  netactuate.compute.node:
    auth_token: "{{ auth_token }}"
    hostname: "{{ inventory_hostname }}"
    plan: "{{ plan }}"
    location: "{{ location }}"
    image: "Ubuntu 24.04 LTS (20240423)"
    script_type: "cloud-init"
    script_content: "{{ lookup('file', 'cloud-init.yaml') | b64encode }}"
    state: present

Using Cloud-Init with Terraform​

resource "netactuate_server" "web" {
  hostname     = "web01"
  plan         = "VR8x4x50"
  location     = "LAX"
  image        = "5787"
  ssh_keys     = [var.ssh_key_id]
  cloud_config = file("cloud-init.yaml")
}

Need Help?​

If you need assistance, visit our support page.