---
description: |
  The `ucloud-uhost` Packer builder plugin provides the capability to build
  customized images based on an existing base image for use in UHost Instance.
page_title: UCloud Image Builder
---

# UCloud Image Builder

Type: `ucloud-uhost`
Artifact BuilderId: `ucloud.uhost`

The `ucloud-uhost` Packer builder plugin provides the capability to build
customized images based on an existing base image for use in UHost Instance.

This builder builds an UCloud image by launching an UHost instance from a source image,
provisioning that running machine, and then creating an image from that machine.

## Configuration Reference

The following configuration options are available for building UCloud images. They are
segmented below into two categories: required and optional parameters.

In addition to the options listed here, a
[communicator](/docs/templates/legacy_json_templates/communicator) can be configured for this
builder.

~> **Note:** The builder doesn't support Windows images for now and only supports CentOS and Ubuntu images via SSH authentication with `ssh_username` (Required) and `ssh_password` (Optional). The `ssh_username` must be `root` for CentOS images and `ubuntu` for Ubuntu images. The `ssh_password` may contain 8-30 characters, and must consist of at least 2 items out of the capital letters, lower case letters, numbers and special characters. The special characters include `()~!@#\$%^&\*-+=\_|{}\[]:;'<>,.?/`.

### Required:

@include 'builder/ucloud/common/AccessConfig-required.mdx'

@include 'builder/ucloud/common/RunConfig-required.mdx'

@include 'builder/ucloud/common/ImageConfig-required.mdx'

### Optional:

@include 'builder/ucloud/common/AccessConfig-not-required.mdx'

@include 'builder/ucloud/common/RunConfig-not-required.mdx'

@include 'builder/ucloud/common/ImageConfig-not-required.mdx'

## Examples

Here is a basic example for build UCloud CentOS image:

<Tabs>
<Tab heading="JSON">

```json
{
  "variables": {
    "ucloud_public_key": "{{env `UCLOUD_PUBLIC_KEY`}}",
    "ucloud_private_key": "{{env `UCLOUD_PRIVATE_KEY`}}",
    "ucloud_project_id": "{{env `UCLOUD_PROJECT_ID`}}"
  },

  "builders": [
    {
      "type": "ucloud-uhost",
      "public_key": "{{user `ucloud_public_key`}}",
      "private_key": "{{user `ucloud_private_key`}}",
      "project_id": "{{user `ucloud_project_id`}}",
      "region": "cn-bj2",
      "availability_zone": "cn-bj2-02",
      "instance_type": "n-basic-2",
      "source_image_id": "uimage-f1chxn",
      "ssh_username": "root",
      "image_name": "packer-test{{timestamp}}"
    }
  ]
}
```

</Tab>
<Tab heading="HCL2">

```hcl
// .pkr.hcl file
variable "ucloud_public_key" {
  type = string
  default = "xxx"
}

variable "ucloud_private_key" {
  type = string
  default = "xxx"
}

variable "ucloud_project_id" {
  type = string
  default = "xxx"
}

source "ucloud-uhost" "basic-example" {
  public_key        =  var.ucloud_public_key
  private_key       =  var.ucloud_private_key
  project_id        =  var.ucloud_project_id
  region            =  "cn-bj2"
  availability_zone =  "cn-bj2-02"
  instance_type     =  "n-basic-2"
  source_image_id   =  "uimage-f1chxn"
  ssh_username      =  "root"
}

build {
  source "sources.ucloud-uhost.basic-example" {
    image_name =  "packer-test-${timestamp()}"
  }
}
```

</Tab>
</Tabs>

Here is a example for build UCloud Ubuntu image:

<Tabs>
<Tab heading="JSON">

```json
{
  "variables": {
    "ucloud_public_key": "{{env `UCLOUD_PUBLIC_KEY`}}",
    "ucloud_private_key": "{{env `UCLOUD_PRIVATE_KEY`}}",
    "ucloud_project_id": "{{env `UCLOUD_PROJECT_ID`}}",
    "password": "ucloud_2020"
  },

  "builders": [
    {
      "type": "ucloud-uhost",
      "public_key": "{{user `ucloud_public_key`}}",
      "private_key": "{{user `ucloud_private_key`}}",
      "project_id": "{{user `ucloud_project_id`}}",
      "region": "cn-bj2",
      "availability_zone": "cn-bj2-02",
      "instance_type": "n-basic-2",
      "source_image_id": "uimage-irofn4",
      "ssh_password": "{{user `password`}}",
      "ssh_username": "ubuntu",
      "image_name": "packer-test-ubuntu{{timestamp}}"
    }
  ],

  "provisioners": [
    {
      "type": "shell",
      "execute_command": "echo '{{user `password`}}' | sudo -S '{{.Path}}'",
      "inline": ["sleep 30", "sudo apt update", "sudo apt install nginx -y"]
    }
  ]
}
```

</Tab>
<Tab heading="HCL2">

```hcl
// .pkr.hcl file
variable "ucloud_public_key" {
  type = string
  default = "xxx"
}

variable "ucloud_private_key" {
  type = string
  default = "xxx"
}

variable "ucloud_project_id" {
  type = string
  default = "xxx"
}

variable "password" {
  type  = string
  default = "ucloud_2020"
}

source "ucloud-uhost" "basic-example" {
  public_key        =  var.ucloud_public_key
  private_key       =  var.ucloud_private_key
  project_id        =  var.ucloud_project_id
  region            =  "cn-bj2"
  availability_zone =  "cn-bj2-02"
  instance_type     =  "n-basic-2"
  ssh_password      =  var.password
  source_image_id   =  "uimage-irofn4"
  ssh_username      =  "ubuntu"
}

build {
  source "sources.ucloud-uhost.basic-example" {
    image_name =  "packer-test-ubuntu-${timestamp()}"
  }
  provisioner "shell" {
      execute_command = "echo '${var.password}' | sudo -S '{{.Path}}'"
      inline          = ["sleep 30", "sudo apt update", "sudo apt install nginx -y"]
  }
}
```

</Tab>
</Tabs>

-> **Note:** Packer can also read the public key and private key from
environmental variables. See the configuration reference in the section above
for more information on what environmental variables Packer will look for.

~> **Note:** Source image may be deprecated after a while, you can use the tools like [UCloud CLI](https://docs.ucloud.cn/cli/intro) to run `ucloud image list` to find one that exists.
