Auto Scaling:Use Alibaba Cloud SDK for Python to execute rolling update tasks

Step 1: Install Alibaba Cloud SDK for Python

1. Run the following command to check whether Alibaba Cloud SDK for Python is installed:

   python --version

   If Alibaba Cloud SDK for Python is installed, the following output is displayed.

2. Run the following command to install the dependencies of OOS:

   pip install alibabacloud_oos20190601==3.2.1

Step 2: Execute a rolling update task

1. Create a Python script and enter the following sample code to execute a rolling update task:

   For information about the OOS template parameters in the code, see Template parameters.

   # -*- coding: utf-8 -*-
   import os
   import sys
   
   from typing import List
   
   from alibabacloud_oos20190601.client import Client as oos20190601Client
   from alibabacloud_tea_openapi import models as open_api_models
   from alibabacloud_oos20190601 import models as oos_20190601_models
   from alibabacloud_tea_util import models as util_models
   from alibabacloud_tea_util.client import Client as UtilClient
   
   
   class Sample:
       def __init__(self):
           pass
   
       @staticmethod
       def create_client() -> oos20190601Client:
           """
           Use your AccessKey ID and AccessKey secret to initialize the client.
           @return: Client
           @throws Exception
           """
           # If the project code is leaked, the AccessKey pair may be leaked and the security of all resources in your Alibaba Cloud account may be compromised. The following sample code is provided only for reference. 
           config = open_api_models.Config(
               # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_ID environment variable is configured. ,
               access_key_id=os.environ['ALIBABA_CLOUD_ACCESS_KEY_ID'],
               # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_SECRET environment variable is configured. ,
               access_key_secret=os.environ['ALIBABA_CLOUD_ACCESS_KEY_SECRET']
           )
           config.endpoint = f'oos.cn-hangzhou.aliyuncs.com'
           return oos20190601Client(config)
   
       @staticmethod
       def main(
               args: List[str],
       ) -> None:
           client = Sample.create_client()
           tags = {
               'scaling_group': 'asg-bp1******'
           }
           start_execution_request = oos_20190601_models.StartExecutionRequest(
               region_id='cn-hangzhou',
               template_name='ACS-ESS-RollingUpdateByRunCommandInScalingGroup',
               parameters='''{"invokeType": "invoke",
                           "scalingGroupId": "asg-bp1******",
                           "commandType": "RunShellScript",
                           "invokeScript": "df -h;ifconfig",
                           "rollbackScript": "df -h;ifconfig",
                           "OOSAssumeRole": "",
                           "exitProcess": [
                               "ScaleIn",
                               "ScaleOut",
                               "HealthCheck",
                               "AlarmNotification",
                               "ScheduledAction"
                           ],
                           "enterProcess": [
                               "ScaleIn",
                               "ScaleOut",
                               "HealthCheck",
                               "AlarmNotification",
                               "ScheduledAction"
                           ],
                           "batchNumber": 2,
                           "batchPauseOption": "Automatic"}''',
               tags=tags
           )
           runtime = util_models.RuntimeOptions()
           try:
               # Write code to print the response of the API operation based on your business requirements.
               resp = client.start_execution_with_options(start_execution_request, runtime)
               print(resp.body)
           except Exception as error:
               # Exercise caution when you handle exceptions in actual business scenarios, and do not ignore exceptions in your project. In this example, error messages are printed only for reference. 
               # Print error messages.
               print(error.message)
               # Provide the URL for troubleshooting.
               print(error.data.get("Recommend"))
               UtilClient.assert_as_string(error.message)
   
   if __name__ == '__main__':
       Sample.main(sys.argv[1:])
   

2. Run the Python script and view the response.

   Note

   When you execute a rollback task, enter the execution ID of the source rolling update task. You can obtain information such as the execution ID of the source rolling update task in the command output, as shown in the following figure.

   

Step 3: (Optional) Execute a rollback task

If exceptions occur when rolling update tasks are executed or you want to use previous configurations after rolling update tasks are executed, you can execute rollback tasks to restore the configurations of ECS instances.

1. Create a Python script and enter the following sample code to execute a rollback task:

   For information about the OOS template parameters in the code, see Template parameters. Sample code:

   # -*- coding: utf-8 -*-
   import os
   import sys
   
   from typing import List
   
   from alibabacloud_oos20190601.client import Client as oos20190601Client
   from alibabacloud_tea_openapi import models as open_api_models
   from alibabacloud_oos20190601 import models as oos_20190601_models
   from alibabacloud_tea_util import models as util_models
   from alibabacloud_tea_util.client import Client as UtilClient
   
   
   class Sample:
       def __init__(self):
           pass
   
       @staticmethod
       def create_client() -> oos20190601Client:
           """
           Use your AccessKey ID and AccessKey secret to initialize the client.
           @return: Client
           @throws Exception
           """
           # If the project code is leaked, the AccessKey pair may be leaked and the security of all resources in your Alibaba Cloud account may be compromised. The following sample code is provided only for reference. 
           config = open_api_models.Config(
               # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_ID environment variable is configured. ,
               access_key_id=os.environ['ALIBABA_CLOUD_ACCESS_KEY_ID'],
               # Required. Make sure that the ALIBABA_CLOUD_ACCESS_KEY_SECRET environment variable is configured. ,
               access_key_secret=os.environ['ALIBABA_CLOUD_ACCESS_KEY_SECRET']
           )
           config.endpoint = f'oos.cn-hangzhou.aliyuncs.com'
           return oos20190601Client(config)
   
       @staticmethod
       def main(
               args: List[str],
       ) -> None:
           client = Sample.create_client()
           tags = {
               'scaling_group': 'asg-bp1******'
           }
           start_execution_request = oos_20190601_models.StartExecutionRequest(
               region_id='cn-hangzhou',
               template_name='ACS-ESS-RollingUpdateByRunCommandInScalingGroup',
               parameters='''{"invokeType": "rollback",
                           "scalingGroupId": "asg-bp1******",
                           "commandType": "RunShellScript",
                           "rollbackScript": "df -h;ifconfig",
                           "OOSAssumeRole": "",
                           "sourceExecutionId": "exec-c1******",
                           "batchNumber": 2,
                           "batchPauseOption": "Automatic"}''',
               tags=tags
           )
           runtime = util_models.RuntimeOptions()
           try:
               # Write code to print the response of the API operation based on your business requirements.
               resp = client.start_execution_with_options(start_execution_request, runtime)
               print(resp.body)
           except Exception as error:
               # Exercise caution when you handle exceptions in actual business scenarios, and do not ignore exceptions in your project. In this example, error messages are printed only for reference. 
               # Print error messages.
               print(error.message)
               # Provide the URL for troubleshooting.
               print(error.data.get("Recommend"))
               UtilClient.assert_as_string(error.message)
   
   
   if __name__ == '__main__':
       Sample.main(sys.argv[1:])
   

2. Run the Python script and view the response.

   The following figure shows an example.

Template parameters