Elastic Compute Service:Use Packer to create a custom image

Procedure

Step 1: Install Packer

1. Connect to a Linux instance.

   For more information, see Connect to a Linux instance by using a password.

2. Run the following command to go to the /usr/local/bin directory:

   cd /usr/local/bin

   Note

   The /usr/local/bin directory is included in environment variables. You can install Packer in this directory or a different directory that is added to environment variables.

3. Run the following command to obtain the Packer installation package.

   You can also go to the Install Packer page to obtain a Packer installation package that is suitable for the operating system and architecture of the Linux instance. In this example, the packer_1.8.5_linux_amd64.zip installation package is obtained.

   wget https://releases.hashicorp.com/packer/1.8.5/packer_1.8.5_linux_amd64.zip

4. Run the following command to decompress the Packer installation package:

   unzip packer_1.8.5_linux_amd64.zip

5. Run the following command to check whether Packer is installed and check the version of Packer:

   packer -v

   • If Packer is properly installed, a Packer version number is returned.

   • If Packet is not installed, the command not found message is returned. Check whether the directory in which Packer resides is added to environment variables.

Step 2: Define a Packer template

To create a custom image by using Packer, create a template in the HCL or JSON format. In the template, specify a builder and a provisioner. For more information, see Builders and Provisioners. Packer provides various provisioners that you can use to create custom images. In this example, a Shell provisioner is used.

1. Run the following command to import your AccessKey ID:

   export ALICLOUD_ACCESS_KEY=<AccessKey ID>

   In the preceding command, replace <AccessKey ID> with your AccessKey ID. For information about how to query the AccessKey ID of a RAM user, see View the information about AccessKey pairs of a RAM user.

2. Run the following command to import your AccessKey secret:

   export ALICLOUD_SECRET_KEY=<AccessKey Secret>

   In the preceding command, replace <AccessKey Secret> with your AccessKey secret. The AccessKey secret of a RAM user is displayed only when you create the AccessKey pair for the RAM user. You cannot query the AccessKey secret after the AccessKey pair is created. For more information, see Create an AccessKey pair.

3. Run the following command to create a file named alicloud.

   Note

   You can create the alicloud file in the HCL or JSON format. If you create the file in the HCL format, perform the subsequent operations that are suitable for a template in the HCL format.

   HCL file

   vi alicloud.pkr.hcl

   JSON file

   vi alicloud.json

4. Press the I key to enter the Insert mode, configure the parameters in the following content based on your business requirements, and then paste the content to the alicloud file:

   HCL file

   variable "access_key" {
     type    = string
     default = "${env("ALICLOUD_ACCESS_KEY")}"
   }
   
   variable "secret_key" {
     type    = string
     default = "${env("ALICLOUD_SECRET_KEY")}"
   }
   
   source "alicloud-ecs" "autogenerated_1" {
     associate_public_ip_address = true
     image_name                  = "packer_basic"
     instance_type               = "ecs.g6.large"
     internet_charge_type        = "PayByTraffic"
     io_optimized                = true
     region                      = "cn-qingdao"
     skip_image_validation       = true
     source_image                = "aliyun_3_x64_20G_alibase_20220907.vhd"
     ssh_username                = "root"
   }
   
   build {
     sources = ["source.alicloud-ecs.autogenerated_1"]
     provisioner "shell" {
       inline = ["sleep 30", "yum install redis.x86_64 -y"]
     }
   }

   JSON file

   {
        "variables": {
          "access_key": "{{env `ALICLOUD_ACCESS_KEY`}}",
          "secret_key": "{{env `ALICLOUD_SECRET_KEY`}}"
        },
        "builders": [{
          "type":"alicloud-ecs",
          "region":"cn-qingdao",
          "image_name":"packer_basic",
          "source_image":"aliyun_3_x64_20G_alibase_20220907.vhd",
          "associate_public_ip_address":true,
          "ssh_username":"root",
          "instance_type":"ecs.g6.large",
          "internet_charge_type":"PayByTraffic",
          "io_optimized":true,
          "skip_image_validation":true
        }],
        "provisioners": [{
          "type": "shell",
          "inline": [
            "sleep 30",
            "yum install redis.x86_64 -y"
          ]
        }]
      }

   The following table describes the parameters.

   Metadata item	Cluster Description
   region	The region in which the temporary instance that is used to create the custom image resides. Example: cn-qingdao.
   image_name	The name of the custom image. Example: packer_basic.
   source_image	The name of the base image that is used to create the temporary instance. You can obtain the name of the base image from the public image list in the ECS console or by calling the DescribeImages operation. Important Make sure that the base image that you select supports the instance type that you specify to create the temporary instance. For example, if the base image is an Arm image whose ID contains _arm64_, you must specify an Arm-based instance. Otherwise, the custom image cannot be created.
   instance_type	The instance type of the temporary instance that is used to create the custom image. Example: ecs.g6.large. After the custom image is created, the temporary instance is automatically released. Note When Packer creates the custom image, the CreateInstance operation is called to create a temporary instance. The instance contains the operating system and software that are required to create the custom image. The temporary instance is a pay-as-you-go instance. You are charged for the instance.
   internet_charge_type	The billing method for network usage of the temporary instance that is used to create the custom image. Valid values: PayByBandwidth: pay-by-bandwidth. PayByTraffic
   provisioners	The type of provisioner that is used to create the custom image. Valid values: File PowerShell Shell Local Shell Windows Shell For more information, see Provisioners.

5. Press the Esc key, enter :wq, and then press the Enter key to save your changes and exit the Insert mode.

Step 3: Create a custom image by using Packer

To create a custom image by using the Packer template that you created, perform the following operations:

1. Run the following command to create a custom image.

   HCL file

   packer build alicloud.pkr.hcl

   The following sample command output indicates that a custom image whose ID is m-m5e3f0gu2dxs4z0s**** is created in the China (Qingdao) region:

   alicloud-ecs.autogenerated_1: output will be in this color.
   
   ==> alicloud-ecs.autogenerated_1: Prevalidating source region and copied regions...
   ==> alicloud-ecs.autogenerated_1: Prevalidating image name...
       alicloud-ecs.autogenerated_1: Found image ID: aliyun_3_x64_20G_alibase_20220907.vhd
   ==> alicloud-ecs.autogenerated_1: Creating temporary keypair: packer_64bf3d40-2fe7-8251-276d-df59a0bb****
   ---------------------------
   ==> alicloud-ecs.autogenerated_1: Provisioning with shell script: /tmp/packer-shell3356722207
       alicloud-ecs.autogenerated_1: Last metadata expiration check: 0:00:11 ago on Tue 25 Jul 2023 11:12:18 AM CST.
   ---------------------------
       alicloud-ecs.autogenerated_1: Complete!
   ==> alicloud-ecs.autogenerated_1: Stopping instance: i-m5e87pt498pr8zv0****
   ==> alicloud-ecs.autogenerated_1: Waiting instance stopped: i-m5e87pt498pr8zv0****
   ==> alicloud-ecs.autogenerated_1: Creating image: packer_basic
       alicloud-ecs.autogenerated_1: Detach keypair packer_64bf3d40-2fe7-8251-276d-df59a0bb**** from instance: i-m5e87pt498pr8zv0****
   ==> alicloud-ecs.autogenerated_1: Cleaning up 'EIP'
   ==> alicloud-ecs.autogenerated_1: Cleaning up 'instance'
   ==> alicloud-ecs.autogenerated_1: Cleaning up 'security group'
   ==> alicloud-ecs.autogenerated_1: Cleaning up 'vSwitch'
   ==> alicloud-ecs.autogenerated_1: Cleaning up 'VPC'
   ==> alicloud-ecs.autogenerated_1: Deleting temporary keypair...
   Build 'alicloud-ecs.autogenerated_1' finished after 4 minutes 32 seconds.
   
   ==> Wait completed after 4 minutes 32 seconds
   
   ==> Builds finished. The artifacts of successful builds are:
   --> alicloud-ecs.autogenerated_1: Alicloud images were created:
   
   cn-qingdao: m-m5e3f0gu2dxs4z0s****

   JSON file

   packer build alicloud.json

   The following sample command output indicates that a custom image whose ID is m-m5e3f0gu2dxs4z0s**** is created in the China (Qingdao) region:

   alicloud-ecs output will be in this color.
   
   ==> alicloud-ecs: Prevalidating image name...
       alicloud-ecs: Found image ID: aliyun_3_x64_20G_alibase_20220907.vhd
   ==> alicloud-ecs: Creating temporary keypair: packer_6345090e-ec1f-8ea0-348c-f85ba047****
   ==> alicloud-ecs: Creating vpc
   ---------------------------
   ==> alicloud-ecs: Provisioning with shell script: /tmp/packer-shell090019677
       alicloud-ecs: Last metadata expiration check: 0:00:15 ago on Tue 11 Oct 2022 02:12:51 PM CST.
   ---------------------------
       alicloud-ecs: Complete!
   ==> alicloud-ecs: Deleting image snapshots.
   ==> alicloud-ecs: Creating image: packer_basic
       alicloud-ecs: Detach keypair packer_6345090e-ec1f-8ea0-348c-f85ba047**** from instance: i-m5e7it5p4dpwetfr****
   ==> alicloud-ecs: Cleaning up 'EIP'
   ==> alicloud-ecs: Cleaning up 'instance'
   ==> alicloud-ecs: Cleaning up 'security group'
   ==> alicloud-ecs: Cleaning up 'vSwitch'
   ==> alicloud-ecs: Cleaning up 'VPC'
   ==> alicloud-ecs: Deleting temporary keypair...
   Build 'alicloud-ecs' finished.
   
   ==> Builds finished. The artifacts of successful builds are:
   --> alicloud-ecs: Alicloud images were created:
   
   cn-qingdao: m-m5e3f0gu2dxs4z0s****

2. View the created custom image.

   1. Log on to the ECS console.

   2. In the left-side navigation pane, choose Instances & Images > Images.

   3. In the upper-left corner of the top navigation bar, select the region that is specified in the alicloud file. Example: China (Qingdao).

   4. On the Custom Images tab, view the custom image named packer_basic.