What is package association-阿里云帮助中心

When you create a service template, you can use the package association feature to include packages from file-type deployments. This topic describes the package association feature.

How it works

The package association feature lets you define a placeholder in your service template and associate it with a file deployment. When you create a service instance, Compute Nest automatically detects the placeholder and replaces it with the file URL from the deployment that matches the service instance's region.

Procedure

Define a placeholder in the template.
Before you configure a package association, you must define a placeholder. These placeholders have two primary uses: in general-purpose templates or for a MigrateTask resource in a database template.
Package association placeholders use the following formats:
- (Recommended) If the deployment's file URL is a private URL, use the following format: {{ computenest::file::xxx }}.
- If the deployment's file URL is a public URL, use the following format: {{ computenest::publicfile::xxx }}
Note
xxx represents a custom identifier that cannot contain spaces.
- Define a placeholder in a general-purpose template.
  The following example shows how to define placeholders in a template. In this example, a UserData script downloads the files and renames them to TestFirst.txt and TestSecond.tar.
  Note
  - When you define a package association placeholder in a template, we recommend enclosing the placeholder in single ('') or double ("") quotation marks.
  - If you use the wget command to download a file, we recommend adding the -O parameter to specify the output filename.
```
TiDBServer:
    Type: ALIYUN::ECS::InstanceGroup
    Properties:
      ……
      UserData:
        Fn::Sub:
          - |
            #!/bin/sh
            sleep 10
            wget '{{ computenest::file::DemoFirst }}' -O TestFirst.txt
            wget '{{ computenest::file::DemoSecond }}' -O TestSecond.tar
            ……
```
- Define a placeholder in a MigrateTask resource.
```
SQLDump:
    Type: ALIYUN::RDS::MigrateTask
    Properties:
        ……
      DBName: mytest
      DBInstanceId:
        Fn::GetAtt:
          - Database
          - DBInstanceId
      OssObjectPositions: {{ computenest::file::DemoFirst }}
```
Configure package association.
1. On the service creation page, in the Deployment Package Association section, click Select Deployment Package under Set Package Association.
2. In the Select Deployment (Package Association) dialog box, select the file deployment and version to associate.
  If you do not have a file deployment, create one first. For more information, see Create a deployment. The placeholder, such as {{ computenest::file::testfile }}, appears at the top of the dialog box. You can only select file-type deployments. You can add a description as needed.
3. Click OK. The Deployment Association area also contains the Set Image Association (to configure the image to be replaced, such as centos_7, associated resources, such as ECSInstances, and the corresponding deployment), Set Container Image Association (to configure association identifiers and the corresponding deployment), and Set Helm Association settings. If the current template has no Helm configuration, the message "The current template has no Helm association" is displayed.

Examples

When you create a service instance, Compute Nest automatically replaces the placeholders in the template with the file URLs from the associated deployments. Compute Nest selects the URL for each placeholder based on the service instance's region.

The following code shows the result after Compute Nest replaces a placeholder in a general-purpose template.

If the deployment's file URL is a private URL, the result is as follows.

Conditions: {}
Resources:
  ECSInstances:
    Type: 'ALIYUN::ECS::InstanceGroup'
    Properties:
      UserData: |
        #!/bin/sh
        mkdir /root/lzq
        cd /root/lzq
        wget 'https://computenest-artifacts-cn-wulanchabu.oss-cn-wulanchabu-internal.aliyuncs.com/xxx/cn-zhangjiakou/xxx/示例文本.txt'
        wget 'https://computenest-artifacts-cn-wulanchabu.oss-cn-wulanchabu-internal.aliyuncs.com/xxx/cn-guangzhou/xxx/changes.txt'
        wget {{DemoThird}}
      SystemDiskCategory:

If the deployment's file URL is a public URL, the result is as follows.

Properties:
  UserData: |
    #!/bin/sh
    mkdir /root/lzq
    cd /root/lzq
    wget 'https://computenest-artifacts-cn-wulanchabu.oss-cn-wulanchabu.aliyuncs.com/xxx/cn-beijing/xxx/1976虚拟背景.jpg'
    wget {{DemoThird}}
  SystemDiskCategory:
    Ref: SystemDiskCategory
  VpcId:

Note

Because the service instance is deployed in the China (Ulanqab) region, Compute Nest replaces the placeholder with the file URL for that region.

For a MigrateTask resource, Compute Nest formats the file deployment URL as required by the OssObjectPositions parameter.
The OssObjectPositions parameter consists of three parts separated by colons (:): the OSS endpoint, the OSS bucket name, and the object key of the backup file. For example, oss-ap-southeast-1.aliyuncs.com:rdsmssqlsingapore:autotest_2008R2_TestMigration_FULL.bak. For more information, see ALIYUN::RDS::MigrateTask. Compute Nest automatically converts the file deployment URL to this format.
```
},
"OssObjectPositions": "oss-cn-hangzhou-internal.aliyuncs.com:computenest-artifacts-cn-hangzhou:xxx/cn-zhangjiakou/xxx/示例文本.txt",
"DBInstanceId": {
```
Note
Because the service instance is deployed in the China (Hangzhou) region, Compute Nest replaces the placeholder with the file URL for that region.