Create and Import Local Images using Packer

Overview

Packer is a lightweight open-source tool for automatic image packaging launched by Hashicorp Company (for more details, refer to the previous document). SurferCloud now supports one-click importing of homemade local images into the SurferCloud cloud platform thanks to the integration of Packer.

Image Import Example

Next, a CentOS image will be created and imported using Packer. It is shown below:

Packer first makes a RAW image using QEMU Builder (opens in a new tab), stored in a local directory specified by user, and then uses import Post-Processors (opens in a new tab) to store the local image to a UFile specified by user, and automate the import into the SurferCloud cloud platform.

Environment setup

Installing Packer

Follow the official installation document (opens in a new tab) to install Packer

Configure default User

Set keys TEST_PUBLIC_KEY, TEST_PRIVATE_ KEY and project ID TEST_PROJECT_ID as global environment variables (recommended), or specify public_key、 private_key、 project_id explicitly in the json file.

Installing QEMU

Follow the official installation document (opens in a new tab), you can use command line to install, MacOS: brew install qemu, CentOs: yum install qemu-kvm, Ubuntu: apt-get install qemu

Creating a UFile bucket

Follow the official document

Writing JSON File

We use the creation and import of a custom CentOS 6.10 image on MacOs as an example. Firstly, create a clean empty folder as a workspace, switch to that directory, and write a JSON spec file (eg：local.json), as follows ：

{"variables": {
  "test_public_key": "{{env `TEST_PUBLIC_KEY`}}",
  "test_private_key": "{{env `TEST_PRIVATE_KEY`}}",
  "test_project_id": "{{env `TEST_PROJECT_ID`}}",
  "disk_size": "4096",
  "iso_checksum": "0da4a1206e7642906e33c0f155d2f835",
  "iso_checksum_type": "md5",
  "iso_name": "CentOS-6.10-x86_64-minimal.iso",
  "ks_path": "centos-6.10/ks.cfg",
  "mirror": "http://mirrors.ustc.edu.cn/centos",
  "mirror_directory": "6.10/isos/x86_64",
  "template": "centos-6.10-x86_64"
},
  "builders":[
    {
      "type": "qemu",
      "boot_command": [
        "<tab> text ks=http://{{ .HTTPIP }}:{{ .HTTPPort }}/{{user `ks_path`}}<enter><wait>"
      ],
      "boot_wait": "10s",
      "disk_size": "{{user `disk_size`}}",
      "http_directory": "http",
      "iso_checksum": "{{user `iso_checksum`}}",
      "iso_checksum_type": "{{user `iso_checksum_type`}}",
      "iso_url": "{{user `mirror`}}/{{user `mirror_directory`}}/{{user `iso_name`}}",
      "output_directory": "packer-{{user `template`}}-qemu",
      "shutdown_command": "echo 'packer'|sudo -S shutdown -P now",
      "ssh_password": "test_packer",
      "ssh_port": 22,
      "ssh_username": "root",
      "ssh_timeout": "10000s",
      "vm_name": "{{ user `template` }}.raw",
      "net_device": "virtio-net",
      "disk_interface": "virtio",
      "format": "raw",
      "use_default_display": "false",
      "qemuargs": [
        ["-display", "cocoa"]
      ]
    }
  ],
  "post-processors":[
    {
      "type":"import",
      "public_key": "{{user `test_public_key`}}",
      "private_key": "{{user `test_private_key`}}",
      "project_id": "{{user `test_project_id`}}",
      "region":"cn-bj2",
      "ufile_bucket_name": "packer-test",
      "image_name": "packer_import_test",
      "image_os_type": "CentOS",
      "image_os_name": "CentOS 6.10 64bits",
      "format": "raw"
    }
  ]
}

This sets up a qemu Builder and an import Post-Processors (opens in a new tab), where the UFile bucket name and other information are configured.

Writing Kickstart Files

According to the http_directory and boot_command configured in the JSON file above for QEMU, you need to create a ./http/centos-6.10/ directory under the JSON file directory to store the Kickstart file, i.e., ks.cfg, as follows: (Kickstart reference document (opens in a new tab))

install
cdrom
lang en_US.UTF-8
keyboard us
network --bootproto=dhcp
rootpw test_packer
firewall --disabled
selinux --permissive
timezone UTC
unsupported_hardware
bootloader --location=mbr
text
skipx
zerombr
clearpart --all
autopart
auth --enableshadow --passalgo=sha512
firstboot --disabled
reboot

%packages --nobase --ignoremissing
sudo
gcc
make
%end

Running Command Line

By running the command packer build local.json, you can create and import a custom image in one click.

Create Custom Images with Packer Image Upload