动态打包程序变量名称

如何解决动态打包程序变量名称

Use-Case将使用PACKER变量文件在“ us-east-1”和“ us-east-2”区域中构建AWS AMI。对于NV和OH，我可以有两个单独的文件。但是我正在尝试使用相同的变量文件来做到这一点。

基于 Packer_Var_File.json 文件中变量' PACKER_BUILD_REGION '的值，我的打包程序版本应仅选择特定于NV或OH区域的值。任何建议如何实现这一目标？

打包程序生成命令： packer build -var-file Packer_Var_File.json Packer_Build_File.json

Packer_Var_File.json 文件的详细信息，如下所示

{
    "PACKER_BUILD_REGION": "NV","1": "This Section to defined 'North Verginia' REGION SPECIFIC Varianles for AMI Build","!": "================================================================================","NV_region": "us-east-1","NV_vpc_id": "vpc-00112233","NV_subnet_id": "subnet-001122334455","NV_ssh_keypair_name": "NV_SSH_KEY","NV_ssh_private_key_file": "{{user `NV_ssh_keypair_name`}}.pem","NV_security_group_ids": "sg-0101010,sg-0202020,sg-03030303","2": "This Section to defined 'OHIO' REGION SPECIFIC Varianles for AMI Build","@": "======================================================================","OH_region": "us-east-2","OH_vpc_id": "vpc-33221100","OH_subnet_id": "subnet-554433221100","OH_ssh_keypair_name": "OH_SSH_KEY","OH_ssh_private_key_file": "{{user `OH_ssh_keypair_name`}}.pem","OH_security_group_ids": "sg-121314,sg-131517","3": "This Section to defined all COMMON Varianles for AMI Build","#": "==========================================================","KEY_region":               "{{user `PACKER_BUILD_REGION`}}_region","KEY_vpc_id":               "{{user `PACKER_BUILD_REGION`}}_vpc_id","KEY_subnet_id":            "{{user `PACKER_BUILD_REGION`}}_subnet_id","KEY_source_ami":           "{{user `PACKER_BUILD_REGION`}}_source_ami","KEY_ssh_keypair_name":     "{{user `PACKER_BUILD_REGION`}}_ssh_keypair_name","KEY_ssh_private_key_file": "{{user `PACKER_BUILD_REGION`}}_ssh_private_key_file","KEY_security_group_ids":   "{{user `PACKER_BUILD_REGION`}}_security_group_ids","region": "{{ user `KEY_region` }}","vpc_id": "{{user `KEY_vpc_id` }}","subnet_id": "{{user `KEY_subnet_id` }}","ssh_keypair_name": "{{user `KEY_ssh_keypair_name` }}","ssh_private_key_file": ".\\{{user `KEY_ssh_private_key_file`}}","security_group_ids": "{{user `KEY_security_group_ids` }}","aws_access_key": "{{env `AWS_ACCESS_KEY_ID`}}","aws_secret_key": "{{env `AWS_SECRET_ACCESS_KEY`}}","instance_type": "t3.large","iam_profile_name": "Agent_iam_Access","ami_description": "AMI on Windows Server 2019 with JDK 1.8.0_251,Chrome Driver 83.0.3987.106,Chrome Browser 83.0.3987.149,and Selenium 3.7.1 Jar","ami_regions": "us-east-1,us-east-2","ami_users": "01223334444,43322211110"
}

解决方法

您可以在打包程序文件中使用env变量。可以使用用户变量在模板中使用环境变量。 env函数仅在用户变量的默认值内可用，从而允许您将用户变量默认为环境变量。

我刚刚用一个简单的打包程序构建了一个。

var.json

{
    "Data": "{{ env `name`}}"
}

main.json

{
  "builders": [
    {
        "type": "file","content": "{{user `Data`}}","target": "dummy_artifact"
      }
  ]
}

所以现在我必须设置环境变量

1. name=test1 packer build -var-file var.json main.json
2. name=test2 packer build -var-file var.json main.json

第一次运行将创建文件的内容为test1，第二次创建的内容为test2。

---

现在让我们回到您的示例，如果对文件应用相同的方法，它将无法正常工作。例如如下所示：

{
    "PACKER_BUILD_REGION": "{{env `MY_CUSTOM_BUILD_REGION `}}"
}

您不能在变量内使用变量。如果使用此选项，则它将无法正常工作，因为最终值将是NV_region而不是us-east-1

，因此您需要更新变量文件。

因此，您不能；使用变量修改变量，最好使用两个不同的文件进行配置，或者您可以编写自己的bash脚本来生成变量，然后修改变量文件以从{{1}获取值}。